- 1 About this Wiki
- 2 E46 Summary
- 3 Buying an E46
- 3.1 How durable or reliable is the E46? Is it expensive to own?
- 3.2 Options & Package Codes
- 4 E46 Manuals
- 5 Maintenance
- 5.1 Overview/Checklists
- 5.2 Check Engine/Service Engine Soon Light (CEL/SES) scanning for ERROR CODES
- 5.3 Oil service
- 5.4 Inspection I / Inspection II
- 5.5 Transmission fluid
- 5.6 Differential fluid
- 5.7 Brakes
- 5.8 Coolant
- 5.9 Spark Plugs
- 5.10 Cabin Microfilter replacement
- 5.11 Fuel filter replacement & Fuel Pump Diagnosis and Replacement
- 5.12 Engine drive belt chirping/cracking/replacement
- 5.13 Coolant Expansion Tank
- 5.14 Water Pump replacement
- 5.15 Thermostat replacement
- 5.16 Radiator temperature sensor replacement
- 5.17 Power steering fluid flush & Mass Air Flow (MAF) sensor cleaning
- 5.18 Magnetic Infandibulator Replacement
- 5.19 M3 Valve Adjustment
- 5.20 Wiper Blades
- 5.21 Windshield Washer Pump
- 5.22 Power Steering Pump Failure & Replacement
- 5.23 Oil Separator Valve(CCV), Idle Control Valve (ICV), DISA Valve, Lower Intake Boot Replacement
- 5.24 Oil Filter Housing Gasket(OFHG)
- 5.25 Motor Mounts / Engine Mounts
- 5.26 Torque Values
- 5.27 Replacing the Battery
- 6 Add-on Compatibility
- 6.1 Alarm
- 6.2 Satellite Radio
- 6.3 Bluetooth Phone
- 6.4 BMW iPod Adapter
- 6.5 DICE iPod adapter
- 6.6 Dension Gateway iPod adapters
- 6.7 Auxilary Input
- 6.8 Reversing Camera
- 6.9 TV Modules
- 6.10 Rear sunblind
- 6.11 Add on/compatibility discussion
- 7 Audio
- 7.1 I've got NAV and my FM stereo is fading
- 7.2 Changing speed sensitive volume control
- 7.3 How to improve sound quality
- 7.4 H/K Retrofit DIY
- 7.5 Upgrade Threads
- 7.6 Set Radio Tuning for US/Europe
- 8 Brakes
- 8.1 Problems with the ground wire/harness for your brake/tail lights?
- 8.2 What is brake bed-in?
- 8.3 Parking brake adjustment
- 8.4 Should I get a big brake kit?
- 8.5 Bleeding and changing your brake pads
- 8.6 Do I have to replace my rotors at the same time as my pads?
- 8.7 What are the max and min specs for rotors?
- 8.8 What is the min spec for pads and shoes?
- 8.9 Rebuilding your brake calipers
- 8.10 Brake caliper and rotor hat painting
- 8.11 Brake caliper painting
- 8.12 Worn brake pad sensor light reset procedure
- 8.13 Brake Job Torque Values
- 8.14 *************COOLING SYSTEM**************(including belt tensioner/idler pulleys)
- 8.15 HIGHLY RECOMMENDED Cooling System Maintenance (and everything else cooling)
- 9 Electrical
- 9.1 Where is the fuse box?
- 9.2 Relays
- 9.3 Speedometer a little optimistic?
- 9.4 Hidden Onboard Computer Functions
- 9.5 Where can I find switched power (+12v) for accessories?
- 9.6 Want to put your convertible top up/down with the key?
- 9.7 Troubleshooting
- 9.7.1 Turn signal bulb burned out?
- 9.7.2 Tail light ground recall/Does your car think you have a tail light out when you have no burned out bulbs?
- 9.7.3 Electrical systems going whack? (Dying Battery or Failed iBus device)
- 9.7.4 Problems Starting with possible other odd electrical behavior
- 9.7.5 Remote lock/unlock on your key not working?
- 9.7.6 DSC, ABS, and BRAKE lights all illuminated? The "trifecta" of lights, wheel speed sensors, etc.
- 9.7.7 ECU/DME fan behind driver's dash
- 9.8 I/K-Bus Information
- 10 Engine
- 10.1 Alternator Replacement
- 10.2 Oxygen Sensor Replacement
- 10.3 Timing Chain Tensioner Spring Replacement
- 10.4 OIL LEAKS - Valve Cover Gasket, Crankcase Vent/Oil Separator, Oil Filter Housing Gasket, Oil Pan Gasket
- 10.5 CCV Explained
- 10.6 Troubleshooting
- 10.6.1 Check Engine/Service Engine Soon Light (CEL/SES) and scanning for ERROR CODES
- 10.6.2 NO START
- 10.6.3 Engine running rough, stalls at idle, etc?
- 10.6.3.1 Misfire and Lean Code Troubleshooting P0171 P0174
- 10.6.3.2 Fuel Pump Troubleshooting
- 10.6.3.3 Fuel Pressure Specs
- 10.6.3.4 Fuel Volume Specs
- 10.6.3.5 Ignition coils
- 10.6.3.6 Camshaft position sensors
- 10.6.3.7 Crankshaft position sensor
- 10.6.3.8 Cracked intake tube
- 10.6.3.9 VANOS failure
- 10.6.3.10 Secondary Air Control System Codes P0491 & P0492
- 10.6.3.11 Vacuum Fittings on Rear and Underside of Intake Manifold
- 10.6.4 Mass Airflow(MAF)Sensor Testing
- 10.6.5 Horrible Burning Smell/Smoke coming from rear/passenger(US) side of engine (Valve Cover Gasket-VCG)
- 10.6.6 Oil light (yellow or red) illuminates during driving or after shutting the car off?
- 10.6.7 My car whines when I turn the steering wheel
- 10.7 Electrical Connector Junction Box/"Where does this connector go?"
- 10.8 Sock Mod - Solve that power steering fluid splash problem
- 11 Fuel System
- 12 Interior
- 12.1 What is the sensor/light by my headlight switch?
- 12.2 What is the red knob below the rear-view mirror?
- 12.3 How do I know if I've got leather or leatherette?
- 12.4 Interior trim removal/replacement
- 12.5 OEM Homelink Garage Door Opener
- 12.6 OEM ///M dead pedal and aluminum pedals
- 12.7 OEM ///M steering wheel
- 12.8 Red Sharpie Gauge Needle Mod
- 12.9 Angel Eye On/Off Switch
- 12.10 Third Brake Light Removal
- 12.11 Troubleshooting
- 13 Navigation
- 14 Exterior / Body
- 14.1 Wheels/Tires
- 14.2 Aerodynamics/Body Kits
- 14.3 How to fit M3 body parts on a Non-M Car
- 14.4 Where are the jack points on the E46?
- 14.5 Facelifting a pre-facelift Sedan
- 14.6 Exterior trim replacement
- 14.7 Bumper Sag/Gap
- 14.8 Lighting
- 14.9 Lighting troubleshooting
- 14.10 Other Add-ons
- 14.11 Troubleshooting
- 15 Performance
- 15.1 BMW Performance Catalog
- 15.2 Straight line performance / Horsepower
- 15.3 Turning ability
- 15.4 Removing Weight
- 15.5 Driver Skill
- 16 Steering & Suspension
- 17 Transmission
- 18 HVAC - Ventilation & A/C / Climate Control
- 18.1 I hear a beep at 37 degrees fahrenheit (3 degrees celsius). Why?
- 18.2 Switching between Fahrenheit and Celsius
- 18.3 Troubleshooting
- 18.3.1 Erratic fan speed?
- 18.3.2 Does your driver's side A/C blow colder than the passenger side?
- 18.3.3 A/C Evaporator/Expansion Valve DIY (you won't believe the pics)
- 18.3.4 Musty(Gym Sock) Smell from Vents?
- 18.3.5 Getting constant heat even when the AC is on?
- 18.3.6 I hear a "cricket/screeching" from my vents
- 19 Parts?
- 20 OTHER See also (M3, Bentley Service Manual, Other Useful Info)
- 21 External links
About this Wiki
The E46 Wiki should be used as a tool to help all E46 owners. The greatest feature of the Wiki is that anyone with an account on Bimmerfest has the ability to edit it. See something incorrect or notice something missing? Simply click on the edit link to the right of any section. To discuss changes to the Wiki, post a message here.
This Wiki was primarily authored by KrisL - http://www.linquist.net. If you like my posts or the information I provide, please use me as your referrer (Kris Linquist #170334) when joining the BMW Car Club of America ($48/yr). The BMW CCA offers a great magazine with tech tips, high-performance driving schools, car control clinics, autocrosses, social events, and even $500+ off of your next new or CPO BMW after you've been a member for a year (independent of the dealer transaction!). When you join the BMW CCA, you'll automatically become a member of your local chapter. I am a car control driving instructor and autocross coordinator for the Golden Gate Chapter.
What is an E46?
Each BMW body style is assigned a two digit number preceeded by "E". The "E" stands for "Entwicklung", the German word for development. The E46 is the body style for the following models (USA model listing except where noted):
- 316i - sedan - 1999 through 2005 model years (available in EU only)
- 318i - sedan - 1999 through 2001 model years (available in EU only)
- 320i - sedan - 2000 through 2004 model years (available in EU and Canada only)
- 323i - sedan - 1999 through 2000 model years
- 323Ci - coupe - 2000 model year only
- 323Cic - convertible - 2000 model year only
- 323iT - wagon - 2000 model year only
- 328i - sedan - 1999 through 2000 model years
- 328Ci - coupe - 2000 model year only
- 325i - sedan - 2001 through 2005 model years
- 325Ci - coupe - 2001 through 2006 model years
- 325Cic - convertible - 2001 through 2006 model years
- 325iT - wagon - 2001 through 2005 model years
- 325xi - sedan - all wheel drive - 2001 through 2005 model years
- 325xiT - wagon - all wheel drive - 2001 through 2005 model years
- 330i - sedan - 2001 through 2005 model years
- 330Ci - coupe - 2001 through 2006 model years
- 330Cic - convertible - 2001 through 2006 model years
- 330xi - sedan - all wheel drive - 2001 through 2005 model years
- M3 - coupe - 2001 through 2006 model years
- M3 - convertible - 2001 through 2006 model years
The 2006 3 Series sedan and 2007 3 Series coupe are the new body style, the E90.
Changes throughout the E46 run
- Changes from 1999 to 2000
- E46 Coupe launched
- DSC replaces ASC (different traction control systems)
- Auto Recirculation becomes standard
- Light Yellow Metallic will replace Sea Green
- There will be a red interior offered
- The 323 will have 15" Alloy wheels standard (replacing hub caps for no-option package 323s)
- The Premium pkg will have wood trim and moonroof standard, with 16" wheels only (no more 15" offered)
- The 323 will get the Sport/Premium combo package offered
- Coupes get Topaz Blue as a color option
- Power seats are a stand-alone option on 323
- Changes for Sept 1999 Production
- Power seats with driver's seat memory upgraded to include exterior mirror memory.
- Radios will have clock function; as a result, an onboard computer function and the time can be displayed at the same time.
- Child seat tether anchorages added as standard equipment.
- Center console buttons redesigned.
- New key design
- Automatic transmission changes to Steptronic
- Changes from 2000 to 2001
- 323i is replaced by the 325i and receives a the new M54 2.5L engine with 184hp & 175lb/ft of torque.
- 328i is replaced by the 330i and receives a the new M54 3.0L engine with 225hp & 214lb/ft of torque.
- Engine type for 323i and 328i was M52TU, engine type for 325i and 330i is the new M54
- New sport steering wheel with circular airbag cover.
- New dual exhaust from headers to muffler.
- 325i sports package gets 17x8 style 44 wheels.
- 17" rims are standard
- Sports package rims are changed to syle M68 with 17x7.5 up front and 17x8.5 in the rear.
- Brakes are 1" larger
- Headlight washer jets standard on cold-weather package
- Silver trim around headlights
- "Updated" steering (more power assist) Note: Due to customer feedback, there was a midyear change back to a system with less boost, although still more than 323s and 328s had.
- Coupes get titanium front spoiler trim.
- Changes for March 2001 Production
- Gray Green replaces Sea Green on Converts, added to coupes
- Oxford Green replaces Fern Green
- Black Sapphire now available for all
- Orient Blue now available for coupes
- Topaz Blue now avail convert, sedan, wagons
- Gray leather now avail w/Bright Red all models
- Black leather/l'ette now avail w/Gray Green (coupes)
325i and 325iT:
- New standard equipment: foglights, cruise control, & automatic climate control
325Ci and 325Cic:
- New standard equipment: automatic Climate Control
- New standard equipment: power Seats, Harman Kardon stereo, & sport suspension
330Ci and 330Cic:
- New standard equipment: Harman Kardon stereo
- Changes from 2001 to 2002
- NAV systems now have a widescreen 16x9 display.
- E46 Sedans and wagons receive a facelift: New headlight and taillight designs, side directional marker moved and re-shaped, new wider grille, new hood, new front bumpers for 325i and 330i without sport package.
- 18" wheel option offered on the 330s
- Changes for Sept 2002 Production
- Sirius satellite radio now pre-wired on non-navigation cars
- Changes from 2002 to 2003
- NAV system becomes DVD based (Mark IV NAV system). In addition, the navigation system will now be available with in-dash CD-player or cassette player.
- The sound system head unit now has a new auxiliary input (aux input kit required)
- Sedans receive third rear headrest and 3-point seatbelt.
- Rain sensor and automatic headlight control will now be part of the Premium Package.
- Front armrest will be standard in the sedan and sport wagon.
- Moonroof will be standard in the sport wagon.
- Emission regulations established by the California Air Resources Board (CARB) required BMW to sell vehicles with new emission standards in California, Massachusetts, New York and Vermont. In order to comply with these regulations, starting MY03 BMW sold Super Ultra Low Emission Vehicles (SULEV) in these four states.
- BMW offered three SULEV models in the states mentioned above: 325i sedan, sport wagon and coupe (equipped with automatic transmission). There were no AWD SULEV models. For ordering purposes in the four states mentioned, these three SULEV vehicles had their own model designations.
- The difference between SULEV and non-SULEV vehicles extended beyond the emissions rating. Arguably the most important was the warranty: an extensive emissions warranty covers far more. It lasts 15-years and 150,000-miles with no deductible. Some of the differences are obvious (the engine looks different), others not so much: the fuel tank is metal instead of plastic (for evaporative emissions purposes). Originally, only automatic transmission 325 models could be SULEV vehicles, but this changed with the E90 model transition where either transmission could be a SULEV.)
- Tire Pressure Monitor replaces the Flat Tire monitor on vehicles with run-flat tires. The alarm display and button in the middle console remain unchanged.
- 330xi with Sport Package will come with 17" all-season run-flat tires with styling 98 wheels (same as the current run-flat tire option).
- Changes for March 2003 Production
- Performance package introduced on the 330i sedan. It's only offered with a manual transmission and NOT offered with the premium package.
- All E46s are now pre-wired for the BMW bluetooth kit
- All 330 manual transmissions now 6-speed instead of 5-speed
- All steptronic transmissions are now GM, not ZF.
- Changes for Sept 2003 Production
- All 330i/330xi Sedans, and 330Ci Coupes must be ordered with option 403 - moonroof. Additionally, all 330Ci Convertibles for September production must be ordered with ZPP - premium package.
- Myrtle wood is no longer available as a stand-alone option. It will only be available when the Premium Package is ordered.
- A new interior trim will be made available on all 3 Series. SA 426 or Aluminum "Brushed Columns" trim will be available as a no cost option when the Premium Package is ordered. If the Premium Package is ordered and SA 426 is not specified, the car will be equipped with Myrtle Wood trim (as before)
- Cars equipped with Navigation are now pre-wired for Sirius
- SMG or Sequential Manual Gearbox will become available for most rear-wheel drive 3 Series models beginning October 2003 production. It will only be available in conjunction with the sport package. SMG will not be available in conjunction with the Performance Package or all-wheel drive models.
- E46 SMG models were remarkably rough-shifting and problematic. They sold poorly as a result. Very few were ordered and this option was later dropped. While the SMG system used on the 325 was not the same system as used on the M3, both have poor reputations. For full details see the various long-term tests of these drive train combinations in Car and Driver, Automobile, and other enthusiast magazines.)
- June 2003 to December 2003
- M3 CSL production (1400 units)
- Changes from 2003 to 2004
- Performance package now available on coupes and convertibles, as well as with the automatic transmission and the premium package (on all 330s).
- The climate control head unit has a new control button layout (temp, fan and recirc control buttons) for simpler operation and ease of use.
Sedan and wagon:
- The rain sensor and automatic headlight control standard for all Sedans and Sports Wagons. These features were previously only available with the Premium Package (ZPP).
- Automatic STEPTRONIC transmission will be available in conjunction with the Performance Package.
- New Sport Package wheel for 325i Sedan and Sports Wagon. Styling 119 replaces Styling 96.
- New base wheel for the 330i/330xi Sedan and 325xi Sedan/Sports Wagon when equipped with the Sport Package. New wheel replaces Styling 73.
- Titanium exterior trim on the front grille and headlights will no longer be a differentiator for 330i and 330xi Sedans. (The headlights will be black and the front spoiler will be a combination of black and body color.)
Coupes and Convertibles:
- Coupes and convertibles receive a major face lift with a new front grille (larger "BMW kidneys"), revised cleaner looking lower bumper design and front/rear light design including LED tail lights, repositioned side turn signal lights and clear front corners on sport package cars.
- The Xenon headlight package was upgraded to the Adaptive Xenon package for coupes/convertibles only.
- Adaptive Xenons not only auto-level as the standard Xenons do, but they also rotate side-to-side depending on orientation of the steering wheel. The goal is to point the light in the direction the car is traveling. A complex algorithm uses car speed, wheel angle, etc. to determine where to point the lights. Of interesting note is the fact that when the car is not moving, the lights will not turn to the driver's side (this is to avoid potential blinding of oncoming traffic, e.g. at a stop light). The headlight switch must be in the "A" (automatic) position -- turning the headlight switch to the "On" position will auto-level the headlights and turn them on, but they will be fixed straight ahead and not turn left and right.
325i and 325i Sports Wagon:
- Styling 119 (17 x 8) with performance tires replaces Styling 96 when the sport package (ZSP) is ordered. This aligns the 325i with the 325Ci. Now all rear-wheel drive 325 models have the same Sport Package Wheel.
- MY2004 330i/330xi Sedan Base wheel. 325xi and 325xi Sports Wagon Sport Package wheel.
- Styling 137 (17 x 7) with all-season tires replaces Styling 73, also known as the Radial spoke.
- Changes from 2004 to 2005
- Performance package 330s get a perforated leather steering wheel instead of alcantara
- The change was made about halfway through the 2005 model year and driven primarily by the inability of the alcantara wheel to hold up well over time. Prior to May 2005, Performance Package 330s shipped with alcantara, after that they shipped with a perforated leather wheel. Many originally-alcantara Performance Package 330s, however, will have had the alcantara wheel swapped out for leather under warranty due to excessive wear of the alcantara.
- Lumbar seat support added to the premium package on the 325.
- CD shuttle became MP3 compatible
Buying an E46
How durable or reliable is the E46? Is it expensive to own?
Given that the average E46 is 7+ years old, this is a particularly common concern for prospective buyers.
To begin with, "reliability" means different things to different people. To some, a car that starts and runs and doesn't break down frequently would be considered reliable. To others, a "reliable" car is one that runs forever with little or no maintenance. The E46 is of the former--the engines and most of the drivetrain components are first class, though unfortunately there are also peripheral components of questionable design and/or production quality which are likely to fail. If you want or expect a car that will get you where you need to go (provided it is properly maintained), an E46 will do that. If you want a car that you can abuse or neglect, or one that will be absolutely free of any sort of minor nuisance or defect, look elsewhere. That being said, unlike some other BMW's models, the E46 does not have particularly problematic electronics; "gremlins" are unusual. Virtually all of the model's common problems are now well documented, and most are actually fairly easy to diagnose and repair.
The following E46/BMW components can be considered highly dependable (Least likely to cause issues):
The following components are reasonably dependable but do occasionally suffer from minor or seemingly unusual issues (which are generally cheap and/or easy to resolve):
The following components are relatively suspect:
Cost of upkeep varies wildly. The E46 is not an exotic car per se, and does not generally require any special service techniques beyond any other typical import car, though dealerships and many third party shops will attempt to bill you as though it is. Without question, you will save a significant sum of money by performing your own simple repairs and routine maintenance; meanwhile, paying dealership/shop prices for window regulator repairs and blower resistor pack replacements will make it difficult to justify the cost of ownership.
Bottom line, budget about $1000 per year for repairs and maintenance (including tires, brakes, oil, etc) if you perform the maintenance yourself. If you intend to have a third party perform all work, you might realistically expect to spend 2-3x this amount.
What should I look out for?
The E46 doesn't have many significant problem areas and is generally a durable vehicle; however if the car was not maintained at by the PO, you can expect numerous problems just like any used and abused car. If you are going to buy a used E46, avoid cars without a good maintenance and repair history. Luckily, the E46 had free maintenance until 36,000 or 50,000 miles (depending on year), so most early maintenance was performed by BMW dealers. Any dealer should be able to provide the service history with just the last seven digits of the VIN.
Below are some typically and well known issues:
- Window regulators - The windows will then either make clicking noises as they go up/down (sign of a failing regulator) or not operate at all possibly leaving your window partially or fully open. This is an extremely common failure and a clear weakspot on the E46 Sedans. Out of warranty, expect to pay $700+ per door for parts and labor. Some owners had success asking BMW NA to cover all or a portion of the cost for this design defect even when the vehicle was out of warranty.
- Tail lamp wiring - The updated E46 sedan (from 9/01 to 3/05 production) wiring harness has a design defect with grounding wires for the rear lighting that are too small and are made of poor quality materials, thus leading to wiring harness failure due to overheating. As stated in BMW's TSB, "Customers may complain that one of the rear lights is inoperative. CAUSE: Minor corrosion at the 8-pin rear lamp connector creates high resistance causing damage to the connector housing. CORRECTION: Repair the damaged wire(s) and replace damaged connector housing. Install additional ground wires to both left and right rear lamps." This can be easily confirmed by careful examination of the rear lamp wiring connectors which are usually melted. Symptoms include a "burned out bulb" warning in the instrument panel and (intermittently) completely inoperative rear lamp cluster(s). While BMW has a TSB for this problem, many have occurred out of warranty leading to arguments with the dealer (automotive lighting standards are Federally legislated, yet BMW refuses to repair this design defect once the cars are out of warranty). BMW dealers expect $350-$400, or more, PER SIDE to make the tail lamps work. As a result, check for a NHTSA recall (or a class-action lawsuit against BMW) before you pay for repairs. There are many threads on this problem; see the BMW TIS (search for SIB 63 03 06 if the attached link is inop)here. This problem was not limited to US market as you can read here. Cheaper DIY repairs can also be found on a variety of web forums, although your results may vary; here is one: here.
- Cooling system - The cooling system will eventually fail catastrophically due to a disintegrating water pump bearing. When this occurs all coolant is lost within seconds and the engine will overheat instantly (remember, these cars have only a total of ~2 gallons of coolant). A much better water pump than the stock/OEM unit is available from EMP Steward, but it's pricey ($200) compared to stock ($70). Other items on the cooling system that should be considered maintenance items since they will likely/eventually fail are the plastic/electric thermostat and the coolant reservoir. Therefore, preventative cooling system maintenance replacing these items every 60k to 80k miles is strongly advised. If an engine is allowed to seriously overheat the repair costs can reach several thousand dollars because of warped cylinder heads. There is an excellent write-up on the cooling system and components posted as a sticky on E46fanatics.com written by Mango.
- VANOS - Unit wear and failure. This was already the case with the M52 engines in the E36, but it's much easier to repair on the E46's M54 engines since the timing chains do not have to be removed. This defect is mostly related to the Buna o-rings in the unit's control pistons which due to heat induced hardening allow excessive oil bypass, thus leading to less accurate control of camshaft timing. Fluctuating idle or stalling can also be signs of this problem. Depending on maintenance this can already occur at 50K miles. If this defect occurs, there is a noticeable rattle in the engine from the VANOS unit, often around 2,000 rpm and low rpm performance will be affected. Repair is actually relatively easy and a true DIY for someone who has basic skills. Replacing the Buna o-rings with higher quality Viton rings in the VANOS unit will fix the issue. Better yet Dr. Vanos sells complete rebuild and blue printed VANOS units that are even better than new OEM BMW units and Beisan Systems sells the above mentioned Viton seal/o-ring DIY kits. Cam sensors (intake and exhaust) on the VANOS unit are also prone to fail and as small as they are, they are expensive ($100+). The exhaust sensor is usually the first to fail and that occurs often right around 100K miles. It has been proven that ONLY OEM BMW sensors should be installed during repair since all aftermarket units are not that compatible and of lower quality. VANOS units on ZHP cars are especially failure prone for undetermined reasons. Common opinion is that this is related to the more aggressive camshaft profiles.
- Subframe - There are many reports of cracked or torn subframe mounting points. Most often the two rear mounting points below the trunk floor are affected. This occurs more often (but not exclusive to) on the early E46 323/328 models. BMW later improved the subframe mounting points in the trunk floor of the car and in later E46 325i/330i this problem seems to be less common. This problem seems to be so frequent in early E46 cars that a check before buying a 323i/328i IS AN ABSOLUTE MUST! Repairs are very expensive and difficult since the rear axle and subfram have to be removed and the unibody frame and mounting points have to be welded. Recurring stress cracking often occurs even after a repair has been made. You can find more information as well as what it looks like in these threads: Thread 1 Thread 2 Thread 3
- HVAC - Many E46 models have erratic HVAC fan speed condition wherein the instrument panel display indicates a set constant fan speed, yet the fan changes speed on a 1hz rate (constantly up and down), or fails to come on at all. This is almost always results from failure of defective original Final Stage Resistors (FSR) whose design provided insufficient heat sink surface area. The improved design FSR's can be purchased for ~$60 to $80 from a wide variety of vendors; installation threads abound.
- Front control arm bushings - tend to fail after 40-60k miles. You can replace them with Powerflex bushings from Bimmerworld for $149 (pre-pressed into new carriers).
- Ignition Coils - There was a recall for failure-prone Bremi ignition coils. Symptoms include multiple yet intermittent "cylinder misfire" OBD-II codes, among with other difficult to diagnose problems. A dealer can tell you if this TSB/recall has been performed in which all six Bremi coils were replaced. The following build date & VIN ranges were affected by this recall:
- FM Stereo - There was a technical service bulletin for fading FM stereo reception on cars with navigation with the BM53 tuner. The fix is to replace the BM53 tuner in the trunk. Reference service measure #B65-209-04 with your dealer.
- There was a technical service bulletin for a 4000RPM power dip on cars equipped with the ZHP Performance Package. The fix is to send the car's DME to New Jersey for reprogramming. Reference service bulletin # SIB 12 17 05 with your dealer - More info here: http://www.linquist.net/motorsports/bmw/sib121705.txt
- Radiator Cooling Fan - There was a recall of the electric radiator cooling fan on a wide variety of BMW models, to include many early E46's. The problem could result in an engine compartment electrical fire several minutes after the engine was shut off. Several cars (and homes) were destroyed by the resulting fires.
- Sunroof - The sunroof shade track/rails are prone to failure. The sunroof will sometimes fail to operate in the heat on older models.
- Weather Stripping - The interior weather stripping above the coupe doors often falls down after a few years. Easily glued into place. (Some even fell down before the cars were sold new.)
- Erratic Idle - There was a technical service bulletin for an erratic idle with possible stalling. Reference service measure #B12-207-0 with your dealer.
Is the 330/328 worth the price premium over the 325/323?
Nobody can answer this question but you. The 330/328 obviously have more hp and torque, as well as bigger brakes. To make the 330/328 a better value, BMW includes more options as standard with the "up level" model (such as power seats, HK premium sound in later years, trip computer, etc.). Furthermore, there would likely be a premium back when you sell or trade it in. In covertible version the differences are even more pronounced since the convertible is a much heavier car and the substantially higher torque of the 328/330 engines are very helpful. Fuel economy is surprisingly identical between the engines since the smaller engines have to be pushed harder in traffic what the larger engines accomplish with more ease. Test drive a car in your price range and see if it meets your needs.
Should I buy the extended maintenance or extended warranty?
First of all, you should recognize the difference between maintenance and warranty. BMW offered 36,000 mi/3yr or 50,000 mi/4yr free maintenance (depending on year). This maintenance covered oil changes, brakes, and windshield wipers (it may also cover items like coolant or brake fluid flush depending on timing). BMW also offered a 50,000 mi/4yr bumper to bumper warranty, which covers any problems you may have.
If your car has <50,000 miles, then you can extend the free maintenance to 100,000 mi/6yr. This extension can be purchased from any BMW dealer and the maintenance can be performed by any dealer. There are deals out there where dealers are offering the maintenance extension for as low as $950. A single 4-wheel brake job can cost about that much if performed by a dealer. Additionally, worn clutch replacements are included within the extended maintenance plan. If you are comfortable doing your own work, it's rarely worth extending the maintenance.
BMW offers two types of warranty extensions:
- Certified Pre-Owned warranty: The CPO warranty covers you until 6yrs/100k miles from the original in-service date. It covers most of the drivetrain, but NOT most of the electronics. This is generally offered on pre-owned cars sold by a BMW dealer.
- BMW Original Owner Protection Coverage (2OP): This is offered to the original owner or lessee only and can only be purchased while the car is still under the original 4yr/50k mile factory warranty. Its coverage is identical to that of the CPO warranty. More information on this warranty can be found here
Any other warranty offered to you will be underwritten by a third party.
Here's a small FAQ on third party extended warranties:
What are the car/key memory options?
They can be set by a dealer or any independent mechanic with a MODIC3/GT1 BMW diagnostic computer.
The list of programmable options can be found here. http://www.ge39.com/files/BMW_MemoryOptions.pdf
Options & Package Codes
BMW of North America offers specific option packages. Elsewhere in the world, a program called BMW Individual is offered to allow individuals to better mix and match options. Options and packages often have numerical or alphanumerical codes associated with them. These codes are used as shorthand to describe the option or package on many BMW forums around the internet.
Here is a list of option codes in a post by Terry Kennedy.
This information is specific to US-bound E46s.
ZSP - Sport Package
The sport package has been available on all E46 3-series cars. It typically included:
- A 3-spoke multifunction steering wheel
- Sport seats with adjustable thigh support and heavier, more pronounced side bolsters.
- Sport wheels and tires (larger wheels with a different design and lower-profile tires)
- Sport suspension calibration (stiffer springs/shocks). Larger swaybars than standard. Note that 2001 and up 330i sedans got the sport suspension as standard equipment that all Coupes recieved.
ZPP - Premium Package
The premium package has been available on all 3-series cars. It typically included:
- Different wheels/tires [if ordered with the sport package, the sport package wheels/tires superseed]
- A multifunction steering wheel [IF it was not already standard on the vehicle]
- Wood grain interior trim [if ordered with the sport package, the premium package wood is typically installed, unless specifically requested otherwise]
- Rain-sensing windshield wipers (became standard equipment in 2004)
- Auto-dimming rear-view mirror
- Power seats
- Lumbar Support (not available on the 325)
- Moonroof (note: moonroof can also be ordered separately)
ZHP - Performance Package
The performance package was available on 2003-2005 330 sedans (330i) and 2004-2006 330 coupes and convertibles (330Ci/330Cic). In 2003, it was only available with the 6-speed manual transmission and WITHOUT the premium package. In 2004, all performance package cars were also available with the automatic (steptronic) transmission as well as the premium package.
Obviously, the Performance Package is an inclusive optional package incorporating all of the features of the Sport Package, so they're not available together.
Original Press release: The 330i Performance Package has been created exclusively for the U.S. market for enthusiasts by enthusiasts at BMW Individual, a division of BMW M GmbH. There is no aspect of the driving experience that has not been enhanced by the Performance Package. Modifications to the 3.0-liter in-line six-cylinder engine, which include different camshafts and performance-modified Digital Motor Electronics, yield a ten horsepower increase to 235. For the first time in a 330i a six-speed manual transmission will be standard. With the Performance Package it will include a short-throw shifter. The package also includes a shorter final drive ratio. The benefits of these modifications are immediately apparent - the 330i with a Performance Package will accelerate from 0 - 60 miles-per-hour in 6 seconds, about half a second faster than a standard 330i. To match the straight-line performance a new sports suspension, more aggressively tuned than the 330i's standard sport suspension, is mated to 18-inch wheels with mixed-size performance tires. In addition to the wheels and tires the exterior of the 330i Performance Package is distinguished by its Aerodynamic Package, black headlight trim, high gloss shadowline trim and a new exhaust that not only appears but also sounds more aggressive. The look and feel of the interior has been refined with cloth and Alcantara sport seats matching the Alcantara sport steering wheel. An anthracite headliner and Black cube aluminum trim complete an ambiance tailored to the enthusiast. Silver cube aluminum trim is optional. The instrumentation includes red needles while the tachometer reflects the modified engine's 300 higher rpm limit. Production of the 330i Performance Package will begin in March 2003 with the first cars arriving at BMW centers in April.
TEXT COURTESY of BMWNA
Per the BMW press release, this package included the following changes. However, many of these claims have been found to be misleading:
- Engine mods that equal a gain of 10HP & 8 ft/lb of torque by utilizing different camshafts and reprogramming the Digital Motor Electronics to allow a 6800 RPM max (up from 6500).
- 6 speed short throw shifter (for manual transmission equipped cars)
- 3.07:1 Final drive ratio w/ manual trans instead of the standard 2.93:1. Convertibles retained the already installed 3.07 ratio.
- Max Speed Limiter set to 155 mph (instead of 128)
- New M suspension, more "sporty" than standard or poor road package.
There are no "ZHP" specific springs. The same springs are used for comparably equipped 330's for both the ZSP and the ZHP. In both cases, the spring rate for the post 4/01 build ZSP and ZHP is believed to be slightly less than that of the pre-4/01 ZSP
- Firmer shocks (Jounce: front +50%, rear +20%), (Rebound: front +35%, rear -8%)
ZHP does use different dampers than the ZSP. There is a shortage of shock dyno data, but based on the SACHS damping parameter values it is believe the jounce damping is the same but rebound damping is stiffer on the ZHP. Pre-4/01 sport package cars had similar damping values to the ZHP but used the higher grade SACHS "Advantage" dampers rather than the "Super Touring" model.
- Smaller diameter anti-roll bars: 23.5 mm front (v. 24mm pre-04/01 ZSP), 18mm rear (v. 19mm pre-04/01 ZSP)
There is no 18.5 mm rear sway bar offered by BMW for the E46.
- More rigid forward bushings
Front Control arm bushings are the same ZHP/ZSP
- ZHP control arms are different and use a stiffer ball joint
- Lower ride height by 15 mm (.6 inches) utilizing shorter auxiliary springs
Since both the ZSP and ZHP use the same springs, they have the same ride height. Both are 15mm lower than a non-sport E46 -.5 degrees of camber (for a total of -1.1 degrees) Alignment settings are the same ZSP and ZHP
- Exterior trim elements (front & rear fascia, trunk lid spoiler)
- Special exterior trim: Anthracite (charcoal) headlight surrounds, High-Gloss
- Shadowline (black gloss) trim
- Large diameter stainless steel dual exhaust outlets
- Extra thick Alcantara steering wheel (later switched to perforated leather)
- ZSP Sport Seats
- Alcantara & cloth upholstery to replace leatherette and standard trim (leather still optional)
- Choice of "Black Cube" or "Silver Cube" interior trim
- Red needles on the instrument cluster
- Style 135's are added, 18x8.0" front, 18x8.5" rear
- Wider Tires: 225/40ZR-18 in front and 255/35ZR-18 in the rear.
- Reduced steering rack ratio. 13.7:1 versus 15.5:1
All post 4/01 330's use the same ratio steering rack. The ratio of this rack is 13.7:1, it is believed to be different from that used on the 325's
ZCP - Competition Package
The Competition Package was offered on 2005-2006 M3 coupes only. It included:
- Interlagos Blue as a color option
- Larger compound/cross-drilled brakes, with larger rear piston and special brake pads. Same as CSL. *345mm front diameter (20mm larger) and 328mm rear (same diameter as standard)
- M-Track mode DSC (a traction control mode that allows for more 'playing')
- Alcantara M3 steering wheel (audio and cruise control buttons deleted) and Alcantara e-brake handle
- 19" BBS "cross-spoke" design wheels 19"x 8" front/ 19"x 9.5" rear
- Shorter ratio steering rack. 14.5:1 versus 15.4:1. Same as CSL
- Aluminum "Alu Tec" interior trim
ZCW - Cold weather package
The cold weather package has been available on all 3-series and M3 cars. It typically included:
- Pass-through ski bag
- Heated seats
- Headlight washers
Options & Package code discussion
Please discuss this section of the wiki in this thread.
E46 vehicle manuals AND the business CD (radio) manual can be found here. (USA/English)
BMW Oil service/Inspection I/Inspection II checklists can be found here for 2001-2004 model years. Other model years are similar enough to use the same checklist.
Enhanced Maintenance Schedule by Mike Miller of Bimmer and Roundel magazines Check out 
Very good discussion of the most common e46 maintenance/repair issues can be found here.
Check Engine/Service Engine Soon Light (CEL/SES) scanning for ERROR CODES
See Engine/Troubleshooting for more information
Although BMW recommends oil service every 15,000 miles, the majority of forum members perform them at half the interval - every 7500 miles. Oil and filter change info can be found on My330i.com here. Paul180 also has a great DIY here. You can also use an Oil Extractor (Pela makes popular models) to perform the oil change, link 1 is here and link 2 here. There are concerns that an improper oil filter change can lead to leaks at the oil filter housing gasket. See the oil filter housing section under other maintenance for further insight.
You can purchase OEM (Mann brand) filters for under $5 online on sites like Autohaus Arizona or ECS Tuning. If you drive a BMW in the USA, you should always use an oil that meets BMW's LL-01 specification. BMW's LL-04 spec is only approved for non-USA vehicles, and this is due to the formula inconsistencies and high sulfur content of many USA gasolines.
That limits USA drivers to either:
- BMW's own "High Performance SAE 5W-30 Synthetic Oil"
- Oils for sale online, such as:
- Or the four brands listed below:
|Castrol Syntec(Edge) European Formula||SAE 0W-30||BP Lubricants USA|
|Mobil 1||SAE 0W-40||ExxonMobil|
|Pennzoil Ultra Euro||SAE 5W-40||Pennzoil Quaker State|
|Valvoline Synpower MST||SAE 5W-30||Valvoline|
A useful comparison of the pertinent physical data for many US available engine oils which are frequently cited for use in M52/M54 engines is available at:
For those driving BMWs outside the USA, both the USA oils and these listed below are suitable:
|ADDINOL Super power MV 0537||SAE 5W-30||Addinol Lube Oil GmbH|
|Agip Formula LL B 01||SAE 0W-30||ENI S.p.A.Refining and Marketing Division|
|Agip Sint 2000 Evolution||SAE 5W-40||ENI S.p.A.Refining and Marketing Division|
|Agip TECSINT SL||SAE 5W-40||ENI S.p.A.Refining and Marketing Division|
|Aral SuperTronic||SAE 5W-30||Aral|
|AXCL S-Class Motor Oil||SAE 0W-30||AXCL Gulf FZE|
|BP Visco 7000||SAE 0W-40||BP Oil International|
|BP Visco 7000 Special||SAE 0W-30||BP Oil International|
|BP Visco 7000 Turbo Diesel||SAE 0W-40||BP Oil International|
|Castrol Formula SLX LL01||SAE 0W-30||Castrol Limited|
|Castrol Formula SLX Turbo Diesel||SAE 0W-30||Castrol Limited|
|Castrol Formula RS Power and Protection||SAE 0W-40||Castrol Limited|
|Castrol Syntec(Edge)||SAE 0W-30||Castrol Limited|
|Castrol Super Racing 0W-40||SAE 0W-40||Castrol Limited|
|Castrol TXT Softec LL01||SAE 5W-30||Castrol Limited|
|Cepsa Star Mega Synthetic||SAE 0W-30||Cepsa Lubricantes S.A.|
|Elf Excellium LDX||SAE 0W-30||Total|
|Formula Shell Ultra AB||SAE 5W-30||Shell International Petroleum Company|
|Gulf Formula TLX||SAE 0W-30||Total|
|Havoline Synthetic BM||SAE 0W-30||Texaco|
|Igol Process Compact P||SAE 5W-30||Igol France S.A.|
|Jet Top Level||SAE 0W-40||ConocoPhillips GmbH|
|Labo RC||SAE 0W-30||***hs Labo Auto S.A.|
|Liqui Moly Longlife High Tech||SAE 5W-30||Liqui Moly|
|megol Motoren***246;l New Generation||SAE 5W-30||Meguin GmbH|
|Mobil 1 Turbo Diesel||SAE 0W-40||ExxonMobil|
|Motorex Profile B-XL||SAE 0W-30||Bucher AG|
|Motorex Select SP-X||SAE 5W-30||Bucher AG|
|Motul Specific LL-01||SAE 5W-30||Motul S.A:|
|OMV full syn plus||SAE 5W-30||OMV AG|
|Pentospeed 0W-30 VS*||SAE 0W-30||Deutsche Pentosin-Werke|
|Petronas Syntium 3000 LL||SAE 5W-30||Petronas|
|Q8 Formula Special||SAE 0W-30||Kuwait Petroleum|
|Quaker State European Formula Ultra||SAE 5W-30||Pennzoil Quaker State|
|Satoil LazerWay B||SAE 5W-30||Svenska Statoil AB|
|Shell Helix Ultra AB||SAE 5W-30||Shell International Petroleum Company|
|Total/Elf Quartz INEO MC3||SAE 0W-30|
|Titan Supersyn SL||SAE 0W-30||***hs Petrolub AG|
|Valvoline SynPower MXL||SAE 0W-30||Valvoline|
|Veedol Powertron LL01||SAE 5W-30||Veedol International|
|Veedol Syntron||SAE 0W-30||Veedol International|
|Wintershall VIVA 1 Longlife||SAE 5W-30||SRS Schmierstoff Vertrieb GmbH|
|Yacco VX 1600||SAE 5W-30||Yacco S.A.S.|
Resetting the service indicator
The service indicator toggles between "Oil service" and "Inspection", and when reset, begins counting down from approximately 15,000 miles. It gets to zero miles once your car has consumed 2500L of fuel.
Model Year 1999 to Mid-2000
- Locate the 20-pin OBD connector. It is under the hood, passenger side, behind the battery terminal.
- Open the connector, and locate pins 7 and 19. The connector has a pacman in the center, surrounded by two rings of pins. Pin 7 is on the outer ring opposite the pacman's mouth. Pin 19 is on the inner ring 90 degrees clockwise from pin 7. If you don't know where these are, follow the link to pictures below.
- Turn the ignition switch to position 2 (RUN), but not to start - notice that this is different than the process used in slightly older cars.
- Connect together pins 7 and 19 for about 5 seconds, then remove the jumper.
- WARNING - Do not keep the jumper in place longer - if you get to 10 seconds you will reset the Inspection I/II Indicator. (unless of course that is what you are trying to do!)
- Turn off the ignition key.
You should not have the 20-pin DLC connector. You only need to HOLD the left odometer reset button WHILE turning the key to position 1 (Accessory). Keep holding the button for 5 or so seconds until any of the following shows in the display: OIL SERVICE or INSPECTION with RESET or RE. Release the button and press it again for another 5 or so seconds until RESET or RE flash. While the display flashes, press the button one more time briefly. If done correctly, END SIA should show up for a few seconds. All done.
Inspection I / Inspection II
Inspection I should be performed at 30,000, 90,000, and 150,000 miles. Inspection II should be performed at 60,000, 120,000, and 180,000 miles.
For a high level overview of what is included in Inspection I and II, go here
To get started on many of the Inspection II items that are simply 'inspections' of various parts throughout the vehicle, see the three inspection guides posted here
EPBB has written up some great Inspection I/Inspection II instructions that guide you through some of the actual maintenance tasks that you should perform, you can find those here
Here is a service bulletin on how to check your ATF fluid.
Bimmerfest user Torquewrench wrote an awesome how-to on changing your automatic transmission fluid (Esso ATF LT71141) & filter on a ZF auto transmission here:
For the green stickered GM-France built 5L40-E/GM5 (A5S 390R); BMW specifies replacement fill as Texaco ETL 8072-B. It is available in 25 liter bulk containers for about $180 from mileoneparts.com (BMW p/n 83-22-0-403-249)
ATF (ETL 8072B, GM transmission) change DIY by Starless (bimmerfest.com) can be found here
Texaco USA does not stock that product in one liter bottles. I emailed them (Texaco) and they recommended using Havoline Multi-Vehicle ATF.
Havoline's corporate product data sheet cites Havoline Multi-Vehicle ATF as a suitable replacement fill for both ETL 8072-B and ETL 7045-E (used on the ZF trans). A local Havoline distributor will drop ship a box of 12 ea. one (1) quart bottles for about $50. gordo325xiwagon Aug07
Many suggest Redline MTL or D4 ATF in the manual transmission. Some recommend sticking with BMW MTF-LT-2 **Ok to substitute Pentosin 1028AMZ0632 MTF2 (75W-80 GL-4 in 1 liter containers for $18.50 at pelicanparts.com) in place of Lifetime Oil MTF-LT-2(BMW part #: 83-22-0-309-031 5 liter container for $128) Pentosin is the OEM supplier for this fluid.** E46 AWD models' transfer cases use the same fluid type as the transmission.
Castrol VMX80 is also 75W80 GL-4, and since BMW fluids are often rebranded Castrol, there is speculation that it's the same. Unconfirmed as of yet.
bokchoys.com has a good tutorial on changing your differential fluid here. impee.co.uk has a similar one with additional photos here. There is a discrepancy in torque specs between the two tutorials. TIS service instructions from 2005 state that drain plugs with the rubber o-ring should be tightened to 44 ft-lbs/60Nm; drain plugs with the metal seal should be tightened to 48 ft-lbs/65Nm.
Many do-it-yourselfers use Redline or Amsoil 75W-90 GL-5 hypoid gear oil.
Please refer to the Brakes Section of this Wiki for brake options and maintenance information.
Thanks to Paul180, a great DIY can be found here. BMW recommends using only BMW-approved coolants, but many people have used other brands and have noticed absolutely no difference in performance of the coolant or the car. For a detailed explanation of different coolant types, watch this video.
Some feel modern coolants are most likely the same in composition, and pre-mixed 50/50 brands that are sold locally are very good coolants. Some of the most important characteristics of a good coolant are its pH, boiling point, and freezing point. The common coolants perform very well in those three areas.
Please see these threads:
M54 Spark Plug and Coil Pack Replacement DIY Video: https://www.youtube.com/watch?v=sjAojOoi_ZQ
Paul180 also has a DIY that covers spark plugs and the valve cover gasket. Check it out here.
Sidefly has a DIY for his 2001 325Ci available here.
Consider using Permatex Hylomar® Universal Blue Racing Formula Gasket Dressing & Flange Sealant wherever 3 Bond Sealant is required (valve cover gasket half moon shaped areas, oil pan gasket flanges etc. - since 3 Bond Sealant is not readily available)
It is strongly recommended to ONLY use the OEM specified NGK plugs for replacements. Bosch Platinum 4 plugs are also available for the M54 engine but will often not perform, cause misfires and set CEL light and codes. Better stick with the NGKs even though they are more expensive.
Cabin Microfilter replacement
It takes all of 30 seconds, and no tools; why pay the dealer to do this? Paul180 has a good DIY here
Fuel filter replacement & Fuel Pump Diagnosis and Replacement
While BMW considers the fuel filter to be a "lifetime" part which never requires replacement, replacement is relatively cheap insurance against premature fuel pump failure. One US member reported that his filter was nearly clogged at 60k miles (as suggested by an inability to blow through the old filter). In contrast, the new filter had no resistance (akin to blowing through a straw). Look at the fuel color and contents of Solidjake's 88,000 mile old fuel filter after replacement here.
Here's a youtube video on the diagnose and replace process: click here Best to have a near-empty tank of gas if you can before you pull the pump to minimize fuel spillage.
Pumps usually last 6-12 years and can fail due to time as much as miles. Many replace preventively at 10 years or before 150k miles. Running gas of questionable quality and running below 1/4 tank frequently may shorten the life of the pump due to increased contaminants and lack of fuel quantity needed to keep the pump running cool.
Engine drive belt chirping/cracking/replacement
If the main drive belt ("serpentine belt") is making noise, it may be worn, but most likely one of your idler or tensioner pulleys has worn out and is squawking as it turns. It tends to be most noticeable on cold starts in the winter. See the Cooling section below regarding diagnostic/replacement of these pulleys. Cracks- a serpentine belt with a few cracks here and there is ok, but when you see more than a few in a 1-2" section, it's ready to be replaced.
See Paul180's replacement DIY here.
Coolant Expansion Tank
See McCreary's Thread here.
For Expansion Tank DIY by Starless follow this link
Water Pump replacement
See these threads:
M54 Waterpump and Thermostat DIY video on YouTube: https://www.youtube.com/watch?v=rci7ASOme7o
Smolck has DIY videos on his youtube account here.
Possible indication that the Water Pump bearings are failing: here
See Paul180's DIY here.
Radiator temperature sensor replacement
The lower left hose from the radiator holds a temperature sensor that controls the electrical fan. The O-ring seal is known to fail and cause a small but persistent leak that is sometimes hard to detect, and here's a DIY thread by Jcourcoul on how to do the replacement.
Power steering fluid flush & Mass Air Flow (MAF) sensor cleaning
See this thread for more information.
This thread by Starless contains detailed instructions for complete PS flush and PS hoses replacement.
Magnetic Infandibulator Replacement
The Magnetic Infandibulator fits between the guibo and the transmission output shaft. From 6/99 production to 4/00 production, these parts are known to fail under high cornering and torque situations - unfortunately that means you may lose all power while going around a corner at high speed. This sudden forward weight transfer can result in loss of control of the vehicle. BMW has discontinued the replacement part - the only replacement option is to upgrade to the 330i transmission output shaft at a cost of $600+.
More information on infandibulator technology can be found here.
M3 Valve Adjustment
See this thread: Thread 1
Generic retail store wiper blades sizes are commonly recommended at 22" (drivers side) and 19" (passenger side).
The actual factory OEM sizes are somewhat longer at 580mm (22.84") and 500mm (19.69").
The correct Bosch Icon pair are 422A and 419B. Coupe owners have had success running a 424A on the driver side and 420B on the passenger side. For proper install and function, a clip must be removed from the driver arm so the blade swipes properly on the windshield. See this thread at M3Forum.net for details.
BMW dealers sell an insert at very low cost ($2.80 each) which allows one to simply replace the worn rubber element. BMW Part No. 61-61-0-154-440. Installation indications can be found at the end of this thread. Also note that the part numbers for the windshield wipers can be found at RealOEM under the "Vehicle electrical system," section.
Windshield Washer Pump
The windshield/headlamp washer pumps are known to leak and fail after awhile, causing a mysterious puddle of water under the front/passenger side of the car. Pump replacement requires no tools and is fairly straightforward, as shown in this thread. It is advisable to replace both the pump and the washer/strainer assembly at the same time. Sometimes just the gasket around the pump fails.
Power Steering Pump Failure & Replacement
The LF-20 pumps are known to shear the pulley shaft, leaving a pump that looks normal with spinning pulley and no leaks but no power steering. To diagnose, draw some fluid out of the reservoir and start the car. Check to see if fluid is moving. A more definitive check can be done by loosening the serpentine belt and pulling the PS pump pulley towards the front of the car. It shouldn't move more than a hair and should feel some resistance to spinning. Careful - pull it out too far and the all the fluid will leak out. A broken shaft will allow the pulley to spin freely and pull out. A full drain of the system at the steering rack is recommended to get out any metal shavings from the failed pump. Newer LF-30 pumps require a different hose as well when replacing.
See this thread for replacement: 
Oil Separator Valve(CCV), Idle Control Valve (ICV), DISA Valve, Lower Intake Boot Replacement
If your CCV/CVV (Crankcase Ventilation Valve, aka the oil separator valve) is clogged, you might notice an odd "foghorn" or "whistling" sound at engine shutdown (whoosh sound is normal), and typically increased consumption of oil since it can leak and pass oil into the combustion chambers. It is also possible, though apparently not common, that the exhaust will have a lot of blue or gray smoke. (white smoke indicates burning coolant). Other symptoms include rough running, loss of power, and spark plugs wet with oil.
If you are getting the very common fuel control mixture lean or running lean codes from an ODB II code reader the usual but not exclusive source of problems can be either the idle control valve (ICV), DISA valve (also known as the Intake Manifold Resonance Valve), lower intake boot, Mass Airflow (MAF) sensor or a combination of all of those. These are relatively easy DIY's and can all be done together for a low cost. The fuel filter should also be considered in researching these issues.
An excellent writeup of the replacement of these valves and the lower intake boot is in this thread. A video is on page 2 of the cold weather CVV. This DIY shows the ICV, DISA, lower intake boot, and MAF being cleaned as well as belt and thermostat replacement.
An outstanding Oil Separator (CCV/CVV) replacement pictorial guide by Starless can be found here, building on info from the above writeup link.
Bavauto.com did an excellent video (on youtube) of the CCV replacement that can be very helpful with the more difficult parts of the job.
While you're in there: Clean the ICV and throttle body TB. Apply a new TB gasket. Consider changing the oil filter housing gasket OFHG at the same time as removing the OFH gives a nice bit of extra room for reaching under the intake manifold for the CCV job. Also, the MAF sensor can be cleaned any time the intake boots are removed for any reason.
What does a bad DISA valve sound like? Watch and listen: M54 DISA Valve Noise
DISA Rebuild Kit can extend the life of this expensive part - check here. If you need to refresh the gasket only, Fel Pro gasket PN 35489 will work (for 323/328) for cheap and readily available. For 325/330, you can use this o-ring gasket Dorman - Pik-a-Nut O-Ring-Rubber- I.D. 2-1/8 Inch O.D. 2-5/16 Inch Thickness 3/32 Inch at Advance Auto. GAS will also have the o-rings.
Oil Filter Housing Gasket(OFHG)
A common source of an oil leak is located at the Oil Filter Housing Gasket. This is not the rubber ring that you replace when you do an oil change. It is a gasket at the base of the oil filter housing where it attaches to the engine. Some members have reported this as a problem due to using a wrench instead of a 36mm socket when changing the oil filter. A tell tale sign is oil leaking on the right side of the engine block (if facing the engine from the front of the car -- driver's side).
See the complete video DIY on how to remove and replace the oil filter housing gasket here: https://www.youtube.com/watch?v=nYCgnUkDvJk
AlboBMW has provided this excellent DIY . And Bowmang at bimmerforums has provided this DIY  as well as a discussion of the torque issue when doing an oil filter change. In addition some members report leaking at the "freeze plugs" of the oil filter housing. It seems the types of freeze plugs on the oil filter housing varied by model and year. See this excellent e39 Oil Filter Housing Gasket and Freeze plug DIY for a discussion and illustrations. The e39 DIY appears to be the same as the e46.
You will need the following torque specifications for the DIY. All 8mm thread bolts of the 6 on the oil housing should be tightened to 22nm. All other bolts on the housing should be tightened to 35nm. If you replace the high pressure oil hose to the VANOS the banjo bolts should be tightened to 32 nm. The Alternator bolts should be tightened to 22nm.
Motor Mounts / Engine Mounts
See this thread for tips on a fairly simple DIY.
For a general description of torque values for working on your car you may want to reference this PDF . To find the thread size (not the head size) of the bolts you are tightening visit RealOEM . Find the part you are working on and it will list the size of the bolts by thread size (M1, M2, etc).
Replacing the Battery
If you need to replace your battery, reference this thread: (TBD)
All US E46 cars are pre-wired for the BMW alarm, but no US cars come with the alarm standard. The alarm consists of three pieces; The siren, which bolts to the firewall on the engine side (behind the cabin microfilter housing), the motion sensor, which is placed behind the square panel in the center of the headliner, and the tilt/tow sensor, which is bolted to the right side of the inside of the trunk area, above the battery.
The parts cost roughly $230 and most dealers charge $100-300 for installation. It can be installed easily yourself. Lots of alarm information and DIYs can be found here. If you install it yourself, a dealer OR independent mechanic with the appropriate autologic/GT1/Modic3 computer will still need to code the car for the alarm - most charge ~$50 or so.
Don't know if you have the alarm? Pop the square panel in the center of your headliner down (you can pull it with your fingernails - just held up with clips) and see if you find a motion sensor. You can also lock the car with the windows down, leave the area for 60 seconds, then wave your hand in the car to see if it goes off.
A dealer, independent mechanic, or anyone with proper coding software such as PA Soft CAN set the car so that the parking lights blink when the car is locked/unlocked without the alarm being installed.
In addition to the OEM alarm, you may install a DEI shock sensor to make up for the lack of one that BMW does not provide. Solidjake has a simple DIY to hooking up the sensor here.
First, for either XM or Sirius satelite radio, your head unit must be satelite radio ready. All MY 2003 or later non-nav head units are satelite ready. Some MY 2002 may work if they have software version 50 (look here to see how to find out if your '02 has the appropriate software). BMW states that all non-nav 3 series built 9/02 or later are satelite radio ready.
Sirius is available for nav-equipped cars built 9/03 or later, but XM Direct does not work with navigation at this time (they're still working on it). Note that Sirius is not currently available for convertibles equipped with nav AND Assist. An installation kit hasn't yet been released for this configuration, but it should be VERY shortly.
Owners of older non-nav (pre 09/02) cars may circumvent these restrictions by replacing the head unit with the newer model. Those with older nav-equipped (pre 09/03) cars would have to replace their old radio (in the trunk) with the newer BM53 unit and upgrade their nav to the newer system (probably not worth it from a cost perspective).
Although the Sirius kit is not officially available for the 3er Touring due to a lack of an approved mounting location, there is no reason that it wouldn't work if wired just like any of the other 3er models (you'll just have to find an alternative method of securing the unit in the rear trunk area).
Many have been getting contrary answers from their dealers, but Sirius and XM Direct are compatible with BMW Assist.
Sirius and XM Direct are also compatible with the CD changer, but you'll have to make sure you order the right parts. For XM Direct, the part number is XM-RDR-D-101 if you have a CD changer, XM-RDR-D-100 if you do not. For Sirius, see Circle BMW's website at Circle BMW Sirius
The OEM Bluetooth (BT) kit is available for e46's made 3/02 or later. It is compatible with all other BMW options (including the Navigation system) except Assist (on pre-9/04 cars). Starting with 9/04 production (2005 model year), BT came factory installed on cars equipped with Assist (using the same module).
BT on pre-9/04 is very rare, as it would have to be retrofitted by the owner, and is expensive, so don't assume your car has it. Cars came from the factory with a card indicating a BT passcode, even though pre-9/04 cars does not have a BT module. The telephone button on the steering wheel also does not indicate whether a car has BT or not, but merely that the car is pre-wired for a telephone, as indicated by the sticker on the truck lid. On pre-9/04 cars, there will be a separate pairing button (located under the armrest - see install link) on BT-retrofitted cars. On post-9/04 cars, there is no pairing button, and the pairing procedure is slightly different that older models.
If you have the Assist, but would prefer the BT, you can have the BT. It's merely a matter of removing Assist (the BT requires the same harness that the Assist uses). The module is fairly expensive (over $500), and the best sources seem not to be dealers. Many dealers refused to sell to cars equipped with Assist (this may have changed by now, but was the case when the cars were new). Also, most dealers would not install it, as the module swap disabled Assist, so it's strictly DIY. It is a very simple procedure for even the non-mechanically minded, though. Check with Bimmernav  for install instructions, and current prices on a BT module.
Only the primary number for each contact will be available via the BMW phone interface. Some phones will not pair with the vehicle if they contain a large number of stored SMS messages.
Bluetooth Compatibility Information:
Not all phones will work with BMW Bluetooth. Check the make and model of the phone, and make sure too that the phone's software (firmware) version is up to date, even if it's listed as supported by BMW.
Lastly, there are different generations of the BMW Bluetooth kit, so check your vehicle's month of manufacture too, as phone compatibility varies over the years. If retrofitting the Bluetooth module, obtain the most recent model possible.
Cars with BlueTooth can be coded for voice-activated commands by a dealer or a third party application called NavCoder. Its also possible, with the latest modules, that voice-activated commands will already be activated.
BMW iPod Adapter
The BMW-supplied iPod adapter is only available for MY 2002 or later. For MY 2002 e46's, the iPod adapter is not compatible with the tape player headunit. It is also not compatible with the satelite radio or the cd changer for any model year. The iPod adapter can not be used with the Nav system (see aftermarket solutions). If you currently have a CD changer, but would prefer the iPod adapter, you can do so by removing the CD changer.
DICE iPod adapter
The DICE is compatible with the Business or Professional RDS/MD/CD headunits. It is compatible with nav, but not the CD changer. The DICE is also compatible with Sirius.
The DICE unit plugs into the cd changer plug in the trunk. Your car then thinks it has a cd changer installed - you press the MODE button on your NAV to select CDC (cd changer) *or* you press the CD button on your non-Nav radio to select CDC (cd changer mode) once the DICE is plugged in.
You can then use your up & down buttons on your steering wheel to select previous/next track on the iPod.
The DICE will charge your iPod.
When you put your car in CDC mode, the iPod is powered up automatically and begins playing from the point at which you last shut it off. When you turn the car off or put the radio in FM/AM/CD/Aux mode, the iPod automatically shuts down.
The DICE will also display artist/title/track information on the radio or NAV screen.
Installation is fairly straightforward, involving running the cable from the trunk-mounted icelink control box that plugs into your cd changer wires to wherever you want the iPod. Dension sells Proclip dash-board mounts directly on their site. See a picture of KrisL's ipod in the DICE with the proclip dash-board mount here.
If you'd like more information on the DICE or where to purchase it, check out the DICE information thread here.
Dension Gateway iPod adapters
Dension have a number of units that supercede the DICE: The Gateway 100/200/300/400 perform all the same functions as a DICE, while also supporting USB mass storage devices (and thereby virtually all brands of MP3 player, other than just the iPod). Dension also offer the ability to retain the CD changer by providing a switching mechanism between the CD changer and the MP3 player. Lastly, Bluetooth and video integration is also possible with the Gateway. Dension products are not currently distributed in the US.
Post-'02 Business CD Head
In late 2002, the Business CD head was revised to accept an aux in plug at the rear of the unit. Basically, if you have the little black badge inside your trunk lid that says pre-wired for Sattelite radio, this kit should work for you.
See this video DIY for the BMW factory auxiliary input kit installation: https://www.youtube.com/watch?v=qxAGSuHMSVE
You can purchase an auxilary input cable from dealers that provides a generic stereo audio input into the BMW sound system (without the ability to view track information, or control the source device). This is a simple DIY retrofit, but some people may struggle if the vehicle has Nav installed. Electronically-minded people will probably be able to make the cable themselves, as it is no more complicated than two plugs and a resistor.
See this thread for a good DIY.
Pre-'02 head solution
If you are a stud with a soldering iron (or know one maybe at an audio shop or IT shop), you can solder input wires directly onto the circuit board of the pre-'02 business CD heads. Note that you will be soldering in very tight spaces so the utmost care must be taken and you take all responsibility for the outcome. This is for those with very good soldering/electronics skill. See this thread. Or for a different version of the earlier head: here
Nav-equipped vehicles have an unused connection for a reversing camera. This camera can be purchased from BMW as a retrofit, while after-market versions are also available. This input can also be used by DIY enthusiasts to add DVD movie playback capability from an iPod, DVD or a Computer.
A TV module is an easy retrofit for vehicles with Nav as they already have a monitor. There are analogue and analogue/digital TV receivers available from BMW dealers, however both will blank the screen for safety reasons while the vehicle is moving. Third party satellite TV receivers are also available. "By June 12, 2009, federal law requires that all full-power television broadcast stations stop broadcasting in analog format and broadcast only in digital format." FCC notice (wonder what happened to all those analog TV units..)
An electrically operated version was available as a retrofit, but has been discontinued. (The replacement electric blind that is still available does not include the wiring harness needed for a retrofit.)
A manually operated sunshade is also available as well. See this thread for more information and a DIY.
Add on/compatibility discussion
The E46 option/add-on discussion thread can be found here.
I've got NAV and my FM stereo is fading
There was a technical service bulletin for fading FM stereo reception on cars with navigation with the BM53 tuner. The fix is to replace the BM53 tuner in the trunk. Reference service measure #B65-209-04 with your dealer.
Changing speed sensitive volume control
On cars without NAV
First, don't be driving while doing this procedure.
Turn the radio off then on again. Don't touch any button except the 'm' button - the button you use to tune the radio frequency manually. Press and hold the 'm' button for TEN seconds or until the display changes. IIRC, it shows the serial number of the unit. Normally when you press 'm', the display will reflect that by replacing 'ST' (stereo tuning) with 'm'. When holding the 'm' button for this procedure, the display should not do this - you will continue to see 'ST' for the ten seconds.
Now if the display has changed, you are in a configure mode on the radio. If you press the '+' or '-' button you change modes. The mode you want will display as "GAL (1-6)". This mode allows you to adjust the speed-sensitive volume control. Use the radio preset buttons 1-6 to set the amount of volume change you want at speed. Setting 1 is the smallest change, 6 is the highest.
I use 1 with the windows closed, and 4 when it's a nice day and I drive with the windows open which makes for a lot of ambient noise at speed. The car is so quiet with the windows closed that setting 1 is plenty. On my car the default setting from the factory was 3 and it bugged me too.
Then turn the radio OFF to save the settings. Turn it back on and go for a drive to test it. The other semi-useful test mode will tell you the signal strength of any given station from 0 to 15 (highest). Use the preset buttons to change stations in the mode. This capability is probably used in the automatic tuning functions in the radio.
On cars with NAV
Get in the car, close the door, and turn the ignition to position 1 (accessory. As soon as the monitor comes on, press and hold the RDS button for aprox 12 sec. Using the arrow keys, near the Tone and Select buttons, scroll to heading "GAL" (German acronym for speed depandant volume) The default setting will be displayed. To change, use the number keys 1-6, 1 being less increase, 6 being maximum. Edit: The radio needs to be on when making this change.
How to improve sound quality
A replacement set of speakers is the simplest and cheapest way to improve the sound. Upgrade speaker kits, that are a straight swap for the original speakers, are available to match the factory amplifier. You also have many other options, but you need to understand how the factory system works before you embark on an upgrade project.
E46 Sound System Explained
The sound system in your E46 is unique in that it consists of a control unit up front, an amplifier in the trunk, and 10 individual speakers inside the cabin. For those cars with the Business Radio, the front dash mounted "head unit" consists of a radio and a CD or cassette tape player. There is no amplification in the dash mounted unit. For non-US model cars, there are other stereos used, some of which have a traditional head unit that includes the amplification.
If your vehicle is equipped with the BMW Navigation system it is configured similarly except that the radio/tuner is an additional, separate module in the trunk. The amp, radio, and nav computer are all located behind the trim panel inside the left side of the trunk.
The speaker setup in the E46 consists of a 3-way component system up front (2-way for non-H/K coupes) and a 2-way component system in the rear. A component system consists of separate speakers located in key locations within the car's interior.
Each front door has three speakers: a mid-bass driver low in the door panel, a midrange, and a tweeter. In H/K coupes the midrange and tweeter are located next to each other behind the cloth grille next to the chrome door handle, non-H/K couples lose the midrange. In the sedan the midrange is mid-door panel and the tweeter is behind the side view mirror near the a-pillar. For those of you who can count, that's six speakers shared between the two front doors to handle the front stereo image.
In the rear, both models have a pair of mid-bass drivers in the rear deck. The coupes have a tweeter mounted in the rear side panel just above the rear seat arm rest, the sedans have them in the rear doors. That's four more speakers to handle the rear stereo image.
Those cars equipped with the H/K upgrade have two additional speakers under the rear deck. The coupe has an oval shaped assembly in the center of the rear deck that houses two 6x9" subwoofer drivers. The sedan has two separate drivers under the mid-bass locations on the outside corners. Each configuration has a separate amplifier to power the subs.
Each of the 10 speakers in the car are designed to handle a specific range of frequencies. The mid-bass drivers handle low end or bass, the midrange handles vocals and middle range frequencies, and the tweeters handle the high frequencies. The head unit provides the full range of frequencies to the amplifier as a pre-amplified signal. The amplifier splits these frequencies, amplifies them, and sends them to each of the 10 individual speakers inside of the car. The coupe amplifier splits these frequencies differently than the sedan amplifier does because the equalization is customized for each interior specifically. Why? Because the acoustics inside the coupe are different than the acoustics inside the sedan.
As you can see, this system configuration is different than what most of us understand a traditional autosound system to be. In a traditional system, there are four channels (front left, front right, rear left, rear right) amplified and sent to four "speakers" within the car. In traditional systems, those speakers may consist of a 2-way or 3-way setup with a self contained crossover that splits the full-range amplifed signal amongst the two or three drivers.
HK amplifier receives balanced differential signal from a head-unit using two pairs of Signal+ and Signal-(not ground) wires. The voltage level is 12V P-P. It is possible to send unbalanced signal (found in consumer devices) to amplifier by connecting positive side of source to positive signal. In this case, negative signal wires must be grounded to avoid noise and distortion. Otherwise a line converter may be used to convert unbalanced signal.
Upgrades Retaining The Factory Head Unit
For security and aesthetic reasons, retaining the factory head unit is the route most people decide on. This is possible because of the separate amplification that the factory system uses. It is this separate amplification that also poses some challenges with speaker upgrades.
Good - Speakers Only
The basic upgrade consists of speaker replacement only. You retain your factory head unit and amplifier. Because your car has component speakers from the factory, you will need to replace them with component speakers. One vendor, Bavarian Soundworks, has a plug-n-play solution that they have designed to work with the factory amplifier and to fit in the factory locations. Installation is just a remove and replace operation. Those who have done this upgrade say it is an improvement over the stock speakers.
Can you use other brands speakers to do the basic upgrade? You can, however, there are some things to remember. An aftermarket component speaker "system" consists of the speakers and an external crossover. The external crossover is a box full of electronics that connects to a single amplifier channel, and the two (or three) individual speakers connect to the crossover. The crossover filters the frequencies to the individual speakers.
When retaining the factory amplifier you cannot use the crossovers supplied with your aftermarket speaker system because the factory amp is already filtering the frequencies. There is no single full frequency amplified channel to connect the aftermarket crossover to, get it?
Since you cannot use the supplied crossover, your new speakers will likely not sound as good as they did in the store when you listened to them. This is because the factory amplifier is filtering the frequencies based on the ranges that BMW's sound system designers determined to be optimum for the factory supplied speakers installed in the factory locations. When you replace these with different speakers, the filtering may no longer optimum for the new speakers.
In addition, if you want your new speakers to play as loud as the factory originals, you need to "resistance match" the replacement speaker to the original. This is the tough part because most over-the-counter speakers you can buy are 4 ohms, and the mid-bass/woofers in your stock system are 2 ohm rated. If you plug a 4 ohm speaker in place of a 2 ohm, it won't play as loud and you'll be disappointed.
Good II - Add a Sub
You may just want to add a subwoofer to the factory system to provide better low end punch. This is a common and easily implemented upgrade that includes a trunk mounted subwoofer powered by a separate amplifier. The best installation method is to split the front pre-amp signal at the amplifier and send that signal to your new amplifier. Why the front channels? Because you want to volume match the sub to your front sound stage as best as possible and normally you'll have the fader set to bias the front speakers. A separate sub volume control is usually a good idea with this upgrade option.
Better - Amp & Speakers
The next best upgrade replaces the factory amplifier and the speakers. In this author's opinion, these are the weak links in the factory systems. The amps have low quality power, the speakers use flimsy foam surrounds, plastic baskets for non-H/K, small magnets, all very inexpensive and low-budget componentry.
Since the head unit provides four channels of full frequency pre-amplified signals, you can bypass the factory amp and put an aftermarket four channel amp in it's place. Can you retain the factory speakers? Not in this case because with the factory amp out of the equation there is no way to filter the frequencies to the 10 individual speakers inside the car. Your best option is to purchase a new 2-way component system for the front and a coaxial system for the rear, then power these with your external four channel amplifier.
In this configuration you'll have a new tweeter and mid-bass driver up front leaving the factory midrange unused. In the rear you'll replace the deck mounted mid-bass driver with your all-in-one coaxial speaker and the rear tweeters will be unused.
If you have the H/K upgrade, you can retain your factory subwoofers by splitting the front pre-amp signal and sending it to the H/K sub amplifier. Why the front channels? Becuase you'll likely have the fader set to bias the front and you want the subs to match the volume of the front stereo image as close as possible.
Best - Amp, Speakers, and Subwoofer
The best upgrade includes the speaker and amp replacement from the better upgrade and adds a trunk mounted, separately amplifed, subwoofer. This can be accomplished by purchasing a 5 channel amp, or a 4 channel plus a separate dedicated subwoofer amplifier. The sky's the limit on how you want to approach the best upgrade. If you surf around the forums you'll see many creative approaches to subwoofer building and install locations. This author has chosen a single 12" sub in a sealed enclosure.
Upgrades Replacing The Factory Head Unit
If you choose, you can replace the factory head unit. Some go this route if they want current auto stereo technology, or to add aftermarket navigation. This is a valid way to go as well.
Good - Head Unit Only
You can replace the head unit and retain the factory amp and speakers. All you need to do is purchase a new head unit that has at least 4 channels of pre-amp output of around 4 volts max. Doing so will allow you to connect this new non-amplified head to the factory amp.
Better I - Head Unit and Speakers
This is similar to the better above except that you replace the head unit and the speakers and retain the factory amp. The same challenges and problems apply here.
Better II - Head Unit (with Amplification) and Speakers
Similar to the Better I option, this upgrade replaces the factory head unit with an aftermarket unit with built-in amplification. Purchase a four channel amplified head unit, a 2-way component speaker system for the front, and a coax speaker system for the rear. You'll power your new speakers with the on-board amplifier of your new head unit.
Better III - Head Unit (with Amplification), Speakers, add Sub
Similar to Better II, but you add a separate amplifier and subwoofer in the trunk. To accomplish this your new head unit should have at least a subwoofer pre-amp output to connect to your new sub amp.
The Full Monty
The full monty upgrade includes a new head unit with six channels of pre-amp output, an external 5-channel amplifier (or a 4-channel + mono sub amp), new component speaker system for the front, a coax speaker system for the rear, and a trunk mounted subwoofer.
You can also add signal processors, other source inputs, whatever your budget will allow!
H/K Retrofit DIY
If you feel inclined, it is possible to retrofit the H/K sound system into a car that was not originally equipped. Check out this DIY to see how it's done: http://www.mindspring.com/~pmbenn/hk_retrofit.htm
Extensive post/thread on upgrade here
Coupe upgrade thread here
Proper coupe door speaker install thread here
Subwoofer install thread here
Set Radio Tuning for US/Europe
See this thread
Problems with the ground wire/harness for your brake/tail lights?
See this section of the wiki for info on the recall.
What is brake bed-in?
Simply stated, bed-in is the process of depositing an even layer of brake pad material, or transfer layer, on the rubbing surface of the rotor disc. It's an important procedure to follow after installing new pads and rotors. Note that some of the ceramic-type "dustless" pads are recommended to bed gradually per the manufacturer (i.e. Akebonos) in lieu of the more aggressive bedding process described below.
A good how-to can be found here.
Parking brake adjustment
Information can be found in this thread.
Should I get a big brake kit?
E46s come with very good brakes from the factory. If you can engage ABS from freeway speeds (hint: you can!) and you do not experience brake fade, then bigger brakes will NOT make you stop better or faster! All of your braking is done by the tires and ABS modulation at that point.
Bleeding and changing your brake pads
For normal street use, BMW recommends that the brake fluid be replaced (flushed) every two years. This reduces corrosion and preserves pedal firmness and feel. Check out My330i's how-to here. Check out Paul180's how-to here. Change your brake pads: A useful YouTube video here.
Do I have to replace my rotors at the same time as my pads?
It's recommended that you replace rotors and pads together for several reasons:
- BMW pads are fairly abrasive and the rotors soft; therefore, a set of rotors usually only lasts about "1.5 pad lengths" before reaching their minimum thickness spec.
- Rotors are relatively cheap ($60 per for the 330i, less for the 323/325/328) and only take an additional few minutes to replace when replacing the pads
- You'll get better brake feel throughout the life of the pads when bedding new pads against new rotors
What are the max and min specs for rotors?
Rotors should be replaced once they are at the minimum width. You should test the thickness of your rotors at 6 - 8 spots around the rotor and use the thinnest measurement to determine whether to replace your rotors.
What is the min spec for pads and shoes?
Brake pads and emergency/park brake shoes should be replaced when at or close to minimum thickness. This is the measure of how much braking material remains on top of the metal backing plate at the thinnest. If the wear of the pads is not uniform thorought the with of each pad and for all pads in the same axle, the cause should be investigated and corrected. For example, sticking calipers, bent holders, rusted pistons, etc. Due to braking dynamics, the front axle brakes wear faster than the rears, usually to a degree of 2 to 1 or more. Brake pads should all be replaced together on the same axle.
The thickness of the e-brake shoes located in the integrated drum on the rear axle rotors should be measured at several spots; it is mot unusual for uneven wear. If the surface of the shoe is excessively glazed, braking power will be significantly diminished and the shoes should be replaced.
|Front Pads||Rear Pads||e-Brake Shoes|
Rebuilding your brake calipers
If your brake calipers are leaking brake fluid, or the dust boots are damaged, or the piston does not retract easily when changing the pads, or the pads are wearing unevenly, you can consider replacing the seals inside. This is also known as rebuilding the calipers and can be significantly less expensive than replacing them. Sean750 has an excellent how-to here. Note that if the piston is significantly corroded, that caliper will have to be replaced as a whole since the piston is not sold as a separate part.
To see this process in a video, see this thread.
Brake caliper and rotor hat painting
See Paul180's DIY here. Note that brake rotor manufacturers have begun to sell "rustless" rotors that come prepainted or with special coatings that prevent the ugly rusty rotor look.
Brake caliper painting
See the video DIY on painting BMW brake calipers here: https://www.youtube.com/watch?v=keF6DoikTMM
See Ivan's abbreviated DIY with pics -here
Worn brake pad sensor light reset procedure
If you replace the front or rear sensor as part of servicing your brakes, the WORN BRAKE PADS light will not reset by itself. To reset the light, just turn the key ON for 30 seconds. The light will go out - you're done, you can now start the car or just shut it off .
Brake Job Torque Values
Per the Bentley manual...
Caliper Guide Pins: 22 ft-lb (30 Nm)
Rotor retaining screw: 12 ft-lb (16 Nm)
Rear carrier retaining bolts: 48 ft-lb (65 Nm)
Front carrier retaining bolts: 81 ft-lb (110 Nm)
*************COOLING SYSTEM**************(including belt tensioner/idler pulleys)
Overheating in these cars can be the kiss of death. Anything more than the most minor overheat incident can result in expensive damage to the engine. If your temp gauge ever ventures north of straight-up, 12 o'clock normal position, pull over immediately and run your heat to bleed off excess heat from the coolant and shut off the engine. It is not advisable to drive the car at this point as you have likely had a cooling system component failure that must be fixed before running again.
DO NOT OVERFILL your expansion tank. Follow the instructions on the little flap on the e-tank neck: check level on a COLD engine, and make sure the top of the filler neck is between the two lumps on the float stick. Overfilling over-pressurizes the system and will pop the weakest part at the time. This is suspected to be a big contributor to the rash of early leaks/failures.
HIGHLY RECOMMENDED Cooling System Maintenance (and everything else cooling)
The cooling system has several points that require timely preventive maintenance if you don't want to risk serious damage to your engine:
It's not a bad idea to change the water pump, thermostat, belt tensioner pulley and hoses every 60,000 miles. Same for the A/C tensioner pulley as that belt can break and throw the serpentine belt, halting the water pump and damaging other cooling parts, etc. Hydraulic (8mm allen,24Nm) and idler pulley (13?mm, 47Nm) wheels are easily replaced and can be found at forum sponsor parts sites. Mechanical (spring) tensioner pulley wheel (T-50 torx,40Nm) is also easily replaced and a Dayco 89133 should fit (2014 Update - The Daycos used to be made by INA but appear to be made by a Chinese company now so it's recommended to instead use a Gates 38018 - discussion in this thread). You can also replace the entire mechanical or hydraulic pulley assemblies (with pulley wheels included) if necessary.
The coolant expansion tank can crack and require replacement (part is only $80). Recommend replacing preventively at around 80k miles.
The water pump pulley is a composite material that can crack with age. Recommend replacing preventively at around 80k miles.
The radiator's ends are plastic and can crack. They tend to start leaking somewhere past 100k miles (130-150K is good avg) . See this thread for a temporary (or possibly longer) fix for a small leak in the radiator.
The o-ring on the coolant temp sensor in the lower radiator hose can leak, but is easily replaced.
You should always use BMW coolant (mixed 50/50 with distilled water, of course)
DIYs for individual components can be found in the Maintenance section above.
A very thorough write up on the cooling system refresh (including proper bleed procedure) can be found here. Sometimes stubborn air bubbles need to be "flushed out" by performing the proper bleed procedure just mentioned but with the car running and raising the rpms a bit to get the coolant circulating. Only to be done if proper cold bleed doesn't get all the air out for whatever reason.
FAN REMOVAL on the automatic: see this video
PICS of HIDDEN HOSES and HARD PIPES under the intake manifold are in this thread, post #21(pic 2 is hard pipes, pic 4 is hoses)
Programming the Temperature Gauge for "Early Warning" of Overheat
See this thread over on Fanatics.
Where is the fuse box?
The fuse box is accessed by flipping two white tabs on the "ceiling" of the inside of the glove box 90 degrees and pulling it down.
- If you're missing the white fuse card, crowz posted it here.
What equipment utilizes each fuse circuit?
- A supplemental cross-reference list that identifies equipment utilizing each fuse circuit can also be found here
There's a bank for horn, fuel pump, etc. behind/by the fuse panel in the glovebox. There's also a bank for DME, Fuel Injection, etc. under the hood in the Computer box next to the brake reservoir. See charts for relay functions here.
Speedometer a little optimistic?
The ECU purposely makes the speedo read a little high. You can determine your actual speed and see how much error there is by resetting your average speed on the OBC while cruse control is activated.
Here is a picture of a BMW document explaining the phenomenon.
Want to correct the error? You can feed a signal into the speed sensor and then move the speedo needle. That's what Ron Stygar did on his coupe.
Hidden Onboard Computer Functions
- There are a number of "secret" OBC functions which can be enabled to display raw data output on the digital odometer. Some are found during standard operation (e.g. average fuel economy), but many others are unique to the "hidden" mode (e.g. engine speed or vehicle speed).
- Note: these functions will work on ALL US-spec E46 cars, even early 323/325 models which are technically not equipped with the OBC option. The OBC is in fact installed and operative in every E46; as an option, it can be "retrofitted" (activated) by installing the OBC-style turn signal stalk and activating the appropriate trigger during an ECU reflash. The better dealership service departments will know how to do this.
- Instructions to access the hidden OBC functions:
|1. Hold Trip Reset while turning ignition key to on position|
|2. OBC should show "Test"|
|3. Use Trip Reset to select function 19.0 that unlocks all the features|
|4. Wait for display to show "Off"|
|5. Depress Trip Reset for 1/4 second and release it|
|6. With no delay press Trip Reset several times to select one of the following function s|
- BMW E46 On-Board Computer (OBC) Hidden Codes
- example description
-- 1 Car Engine and cluster data
- 1.0 46nnn Chassis nr/VIN serial number (last 5 digits)
- 1.1 4nnn K-number
- 1.2 690236 Cluster Part #
- 1.3 045210 Coding (04)/diagnosis (52)/bus index (10)
- 1.4 1200 Week (12)/year of manufacture (2000)
- 1.5 09_160 Hardware (09) and software # (16.0) of cluster
- 1.6 Not used
- 1.7 04__44 CAN-version (04) **-revision index (44)
-- 2 (test) Cluster System Test - Activates the gauge drivers, indicators and LEDs to confirm function
-- 3 SI Data
- 3.0 1098 Used fuel in liters since last SI (Service Inspection)
- 3.1 0231 Periodic inspection days; elapsed days (since last SI)
-- 4 Momentary Consumption
- 4.0 0145+ Instant fuel consumption - 0145=14.5 liters/100km
- 4.1 0018 Instant fuel consumption - 0018=1.8 l/Hour
-- 5 Distance Gone Consumption
- 5.0 082 Average mileage; 082=8.2 liters/100km
- 5.1 0536 Calc. km to refuel (momentary distance to go)
-- 6 Fuel Level sensor inputs in liters
- 6.0 109330+ Fuel level averaged; Left half sensor input=10.9 liters; Right sensor input=33.0 liters
- 6.1 0439+ Total tank level averaged; vlgs 6.0: 10.9+33.0=43.9 liters
- 6.2 0442+ Indicated value (44.2) and tank phase
-- 7 Temperature and Speed
- 7.0 021+ Coolant/Engine temperature (21°C)
- 7.1 130 Ambient/Outside temperature - chg met 5 pts. 125/130/135
- 7.2 + Engine speed / Current RPMs 1/min
- 7.3 + Vehicle speed / Current Speed in km/hour
-- 8 Input value in HEX form
- 8.0 1d0+ System voltage ADC-Value Hex code
- 8.1 26C33C+ ADC Values HG left/HG right
- 8.2 0000 ADC Value brake degradation sensor (000=o.k.)
- 8.3 18C ADC Value outside temperature
-- 9 Battery
- 9.0 140 Battery Voltage - 140 = UB 14.0v
- 9.1 242013+?
- 9.2 074_78+?
- 9.3 0011+?
-- 10 Country Coding
- 10.0 Code (US = 02)
-- 11 Cluster Code
- 11.0 Code
-- 12 Not used
-- 13 Gong Test
- 13.0 Activate gong by pressing button (gong response is delayed)
-- 14 Not used
-- 15 Status cluster I/O-ports (bit codes) 0=low; 1=high
- 1)-belt contact, seat belt fastened=0;
- 2) ignition lock contact, key inserted=0;
- 3) door contact, door open=0;
- 4) clock button pressed=0;
- 5) SI reset=0, for reset=0;
- 6) EGS transmission failure=0
- Status Digital Outputs (bits) 0=inactive, 1=active
- 1) Gong output;
- 2) Brake warning lamp;
- 3) Low fuel warning lamp;
- 4) EGA lamp;
- 5) seat belt lamp;
- 6) manipulation dot
-- 16 Not used
-- 17 Not used
-- 18 Not used
-- 19 Lock Status; unlocks functions in range 3-18
- 19.0 L-On/L-Off Unlock: press button when "L-Off"
-- 20 Not used
-- 21 Software Reset; reset OBC settings
-- 00 End of test
List courtesy of this guy
Where can I find switched power (+12v) for accessories?
- BMW offers a 12v accessory power cable that plugs into the torch charger in the glove compartment (But is not switched power).
- There's a wiring harness in the headliner console that has +12v for the universal garage door opener (UGDO). It's usually wrapped in black tape and shoved up above the passenger visor area. The +12v wire is green & blue.
- There's a wiring harness in the center console under the coin tray for the analog cellular telephone option. The +12v wire is purple/white.
Ground is always brown.
Want to put your convertible top up/down with the key?
Check out this great how-to over on e46fanatics.
Turn signal bulb burned out?
Here is a DIY on changing your front turn signal bulb.
This is also another good reference for pre-facelift cars.
Tail light ground recall/Does your car think you have a tail light out when you have no burned out bulbs?
First, consider replacing any dark or discolored bulbs with known good bulbs, preferably of the same brand. (However, this is unlikely to solve the problem for long, if at all. Here's why: accessing the bulbs results in moving or josting the wiring. This can make it seem like you've solved the problem, when the problem actually lies within the wiring connections--it is very likely to return.)
Second, examine your tail lamp wiring connectors for evidence of internal overheating. See the instructions in BMW S IB (service bulletin) 63 03 06 . Print this out for your BMW Center if the car is still under any warranty. The bulletin directs replacement of the melted wiring and connectors, and creates a second, more robust, grounding path for both tail lamp assemblies. NOTE: BMW Dealers have been asking $600 to $800+ to repair this known wiring defect. Defects which prevent automotive lighting from meeting FMVSS 108 are subject to recall for a period of at least ten years, and frequently much longer due to liability issues [see http://fmvss108.tripod.com/ for details on the applicable Federal Motor Vehicle Lighting Standard]. From the NHTSA web site: "Safety recall campaigns result from identified component failures which present a risk to highway safety, and from non-compliance with Federal Motor Vehicle Safety Standards. Although a majority of safety recalls are performed by manufacturers without any influence from NHTSA, many result from NHTSA defect investigations and compliance testing."
On 8/7/09, NHTSA opened an investigation of tail lamp electrical connection (ground circuit) issues for all MY 2002 - 2005 E46 sedans. On 12/18/09, NHTSA elevated their investigation to an "engineering analysis" (EA09-019). This investigation is ongoing and NHTSA laboratory investigations of the 'alleged' defect, and a report are expected by June 30, 2010. Interested parties may access the details of this investigation and NHTSA, BMW correspondence by going to NHTSA's web site: "defect investigations."
If you elect to pay for the repair in advance of the recall and/or clas action lawsuit, SAVE ALL RELATED RECEIPTS. You may need receipt copies for full reimbursement from BMW.
On 9/04/2011, NHTSA announced a recall of MY 2002 - 2005 325i, 325xi, 330i, 330xi models built between 9/01/2001 and 3/01/2005 to repair the open ground connection at the 8-pin connnector of the tail light assembly. A total of 241,000 vehicles are affected. The recall identification number is 11V438000. Repairs will be made free of charge. Owner notification is expected to begin in October of 2011. Owner's may Google 'NHTSA Recalls' and enter the appropriate model information to view documents as BMW submits them to NHTSA.
DIY Repair -If you think you have this problem but are outside the coverage dates, here is a thread on the very simple DIY repair.
Electrical systems going whack? (Dying Battery or Failed iBus device)
There are two problems that affect all of your electrical systems. Symptoms include steering wheel buttons not working, turn signals or gauges not working, radio not turning on, etc.
- The most common cause is a failed device on the iBus: try unplugging your cd changer, ipod adapter, satellite radio, etc.
- The second most common cause is simply a bad battery. Batteries on the E46 are known to only last about four years. Using the Hidden Onboard Computer Functions directions above, you can monitor your system voltage. A healthy battery will show around 12 volts with the car off, and around 14 volts while running. A cheaper than OEM replacement battery is the "49DL" available from autozone. Although this battery is of different size and dimension of the OEM battery it can be made to fit and functions properly. Here's a thread with some details: Thread 1. Many festers have also had luck with an Everstart MAXX 94R or RN found at Walmart, which is the correct original size and dimensions as the OEM battery. You can read the details in this thread: Thread 2
- Convertibles have a smaller battery tray in the trunk and are unable to use the 49DL and must use the 94R sized battery.
"49DL" and "94R" are standardized battery sizes that will have specific height, width, and length dimensions. See the threads above for further information.
- If your battery dies and you successfully charge it and restart the car only to find many electrical accessories not working, a "hard" reset of the system may be necessary. This involves removing both battery cables and then shorting them together (NOT the terminal posts on the battery!!!) for up to 30 minutes.
- If you believe your battery and alternator are good, but the battery keeps dying, you may have what is called a parasitic drain - some electrical component stays on when it's not supposed to and drains the battery when the car's not running. See this thread for troubleshooting: Thread 1
The wiring harness to the trunk may also deteriorate over time/use and cause multiple shorts, resulting in the "christmas tree" of lights on the dash and other erratic electrical behavior. See the sticky thread at the top of the e46 forum on this with discussion of remedies.
- Instrument cluster malfunctioning? See OBC computer section above for the cluster test and OBC system reset functions, menu options #2 and #21.
Problems Starting with possible other odd electrical behavior
See this thread for symptoms and ignition switch replacement DIY. Problems with the ignition switch are usually characterized by the starter not engaging every time the key is turned and/or a long delay between turning the key to the start position and the starter actually engaging. Note: starting problems can also be associated with a weak/dead battery (see above in Electrical), fuel/spark problems and/or problems with the starter itself (See No Start under Engine/Troubleshooting below).
Remote lock/unlock on your key not working?
Try re-initializing your key:
- Get in and close all doors.
- Turn on the ignition and turn off quickly. (No more than 5 seconds) to start the process. Next action must take place within 30 seconds.
- Remove the 1st key.
- Hold the key up near your left shoulder (this is so it is closer to the remote reciever antenna - someone else suggested this).
- Hold down the unlock button (which is button 1 on my key) and press the lock button 3 times (center button on my key). Release the unlock button and the doors lock which confirms the operation.
- Quickly repeat steps 4 & 5 for key #2 etc.
If it does not work, try doing the keys in opposite order. Key 2 then key1, vs 1 then 2.
Remember to alternate your keys from time to time so that you keep the batteries in both charged. Some have found success with placing the key into a rechargeable toothbrush charger overnight as well.
Official documentation on key initialization can also be viewed at: http://www.bimmerfest.com/forums/attachment.php?attachmentid=171170&d=1231280426
Another thing you can do is to replace the battery! It's not officially possible (or recommended) for the new key design (2000+) but it can be done. Instructions can be found in this thread. Read the first page or two, but be sure to make note of post #177 about battery terminal positions. Some have had success soldering in a small extension wire where the terminals didn't line up closely with the circuit board connecting points. In a pinch, a 3v calculator battery can be used temporarily until your rechargeable arrives.
DSC, ABS, and BRAKE lights all illuminated? The "trifecta" of lights, wheel speed sensors, etc.
This happens when the car has detected a fault and has disabled the DSC and ABS systems. If you recently drove on ice, a dynamometer, or on another very slippery surface, the car may just /think/ the system has malfunctioned. Driving a few miles on a regular surface should fix the problem. Sometimes a dying battery will produce odd errors like this as well.
How to fix pre-charge pump code error 88: https://www.youtube.com/watch?v=ZB0eMvXyqVs
Another possible fix is to slowly turn the steering wheel from completely left to completely right, then back again.
If you did not recently drive on ice and the wheel turning solution did not work, this is usually caused by either:
- One of your wheel speed / ABS sensors failing (there's one on each wheel) or needs cleaning see here
- The DSC pressure sensor on the brake master cylinder is faulty
- Your steering angle sensor has failed
- Your battery needs replacement
- You maybe in need of an alignment
An independent BMW mechanic should have the autologic/Modic3/GT1 computer required to read the codes to determine the source of the fault. If you want to diagnose the problem yourself, here is a post on e46fanatics that describes how to test each wheel speed sensor. Remove the wheel and identify the wires running from the back of the hub to a disconnectable wiring harness (do not confuse this with the brake pad wear sensor, which is only located on the front left and rear right wheel). Use the procedure above. The sensors are about $100 each.
The steering angle sensor is accessible from inside the cabin. You can find a picture of its location by searching for it on www.realoem.com/bmw.
An in-depth test of the ABS module and possible loose wire fix is discussed in this thread
ECU/DME fan behind driver's dash
See this link for discussion of symptoms and replacement.
Technically speaking, both data busses are the same, but used for different modules. I-Bus is mainly used for multimedia devices such as radio, telephone, steering wheel controls, and so on. On other hand, K-Bus is used for modules such as GM or IHKA. However, both busses are connected to instrument cluster (IKE) which acts as a router between two busses. This allows I-Bus module to send a message to module on K-Bus, and vise versa.
I/K-Bus (further down referred to as a bus) is using single wire for receiving and sending data; pulled high (12V or VBATT) on idle, and down (GND) to send a bit. It operates at the speed rate of 9600 bits per second, 8 data bits, even parity, and single stop bit.
Typical message on a bus has a simple structure.
- 1byte: Source ID
- 1byte: Length
- 1byte: Destination ID
- xbyte: Data
- 1byte: XOR Checksum
Source ID/Destination ID
Identification byte of source and destination modules.
Length of the message following the length byte. A message with 11 bytes with hava "Length" byte set to 9.
Starting with 0x00, each bit in a message is XORed.
Because messages on bus have no start or stop indicator, parsing can be quite a challenge. Below are two methods for doing just that.
This method is simple and fairly straight forward, but it is not optimal with embedded devices with low resources.
More complicated, and more optimal for low resource devices or microcontrollers such as arduino.
A red battery light on your dash or a car that won't start but has a battery you believe to be good can be signs of a failed or failing alternator. Check the main electrical connections to confirm they're clean and properly secured. If the car still has issues but can be driven, most major auto parts stores will test your alternator, battery and starter for free to determine if they're putting out the proper voltage.
Learn how to replace your M54 alternator with this complete video DIY here on YouTube: https://www.youtube.com/watch?v=GQ3wkR_STlI
Replacing an alternator is a fairly easy do-it-yourself. blog.bavauto.com has an excellent write-up here (note: this how-to is for E46s with automatic transmissions; the instructions are identical for a manual transmission except for the radiator fan removal, which is more involved on an automatic).
Sometimes, just the voltage regulator can be replaced (black part that bolts onto the back of the unit) for much less than the whole unit.
A failed alternator has symptoms nearly identical to a failed battery. Make certain you have a correct diagnosis before replacing one or the other.
After replacing your alternator, do not start the car unless your battery is charged.
Oxygen Sensor Replacement
A video DIY for the M54 oxygen sensor removal and replacement can be found here: https://www.youtube.com/watch?v=21E5_u6dz0s
A video for the pre-cat sensors can be found here: http://www.youtube.com/watch?v=DmW7mo-yLr8
Timing Chain Tensioner Spring Replacement
As the engine gets beyond 150k miles, the timing chain has stretched/worn a little and the tensioner spring has lost some tension so it is probably a good idea to replace the spring. This thread has a DIY and some discussion.
OIL LEAKS - Valve Cover Gasket, Crankcase Vent/Oil Separator, Oil Filter Housing Gasket, Oil Pan Gasket
The most common oil leak spots are the VCG - Valve Cover Gasket (see Engine/Troubleshooting below); CCV - Crankcase Vent/Oil Separator and related hoses(see Maintenance above); the OFHG - Oil Filter Housing Gasket (see Maintenance above); and the Oil Pan Gasket. Make sure you know exactly where the oil is coming from as all the oil leaks run down and probably make the oil pan gasket look like it's leaking whether it is or not.
The oil pan gasket is very difficult to repair as it involves lowering the oil pan, which involves lowering the front subframe cross-brace (metal "belly pan"). See this thread for discussion and DIYs.
.The crankcase vacuum valve, also known as the positive crankcase vacuum valve (CCV/CVV/PCV) all refer to the same system and are a common source of vacuum leaks, rough idles, and misfires. It is often recommended to check and replace the valve and hoses. Because it is so often recommended, it is good to attempt to explain what this system does and why it can cause engine problems.
In an engine, after intake, the cylinder is sealed, and piston compresses unburnt air and fuel before spark. As a piston can never have a truly perfect seal, a small amount of this unburnt air/fuel mixture will leak into the crankcase: the otherwise sealed area below the pistons where hot oil is flung about. Left to its own devices, a sealed crankcase will build pressure from cylinder leakage and burst. Therefore, in the early days of the automobile, crankcases had small exhaust vents to relieve this pressure into the atmosphere.
However, it was found that half of all engine pollutants were coming from this crankcase vent. Because the vented gasses consisted mostly of unburnt air and fuel in the proper ratio, engineers soon realized they could recirculate these gasses back into the engine intake, giving it another chance to be burned in the cylinder. This process makes the engine more fuel efficient and produce fewer emissions. Later developments added a valve which maintains slightly positive pressure in the crankcase, which improves emissions even more.
This is what a CCV system is. The CCV system in BMW M52TU and M54 engines in E46 cars use two hoses in the crankcase to relieve pressure. These two hoses channel crankcase gasses to the CCV valve itself, located next to the throttle. This analog valve regulates the pressure in the crankcase and separates out any oil vapors that may have tagged along, which drips down a third hose to the dipstick (this is the hose that most commonly fails). A fourth hose recirculates the unburnt air and fuel back to each of the six cylinders using a small, spindly, dedicated manifold above the normal intake manifold.
Vacuum leaks: In an engine, vacuum leaks are caused by air leaks in the intake system, which enables extra air to be added downstream the MAF sensor and dilutes the precise air/fuel mixture calculated by the ECU, causing misfires. Knowing that, it's easy to see how a cracked hose in the CCV system can cause misfires or vacuum leaks, as the CCV system basically functions as a second intake system, with plenty of opportunity to inject extra air into the combustion cycle. Many videos exist on how to change the hoses, and usually contain a humorous scene where the host of the video holds an old, "flexible" CCV hose to the camera and snaps it in two, showing how brittle it had become. If your car is misfiring or producing lean codes and the primary intake system is sealed, you may have a vacuum leak in one of the CCV hoses. Other symptoms include unusual oil consumption. The oil drip hose from the CCV valve frequently breaks, dripping separated oil onto the street.
How to tell if your CCV valve has failed: CCV Oil Cap Test
Lean Codes caused by defective CCV valve and diagnosing: P0171 and P0174 Lean Codes DIY Video
Check Engine/Service Engine Soon Light (CEL/SES) and scanning for ERROR CODES
The check engine light comes on when the key is turned to position II (key on, engine off) as a test of the bulb/circuit itself. If your check engine light is on while the car is running, the car's diagnostic computer has detected an error from one of the many monitoring sensors on the car. Some errors can be as simple as not tightening the gas cap enough (in which case the SES light will turn off by itself after resolving the issue and some driving), or slightly more involved, like a cracked and leaky rubber tube/boot that takes air from the air filter box to the engine (which, to turn off the service light, will require correcting the problem and clearing the code logged in the computer with a scan tool). The best course of action when this light appears is to obtain a scan tool and scan the computer for the error codes (aka diagnostic trouble codes DTCs).
Peake makes scan tools that read BMW specific codes, and there are many "universal" code readers out there from other vendors that will also work very well with your BMW. Autel makes a popular model, probably due to it's affordability - the MS300. There are also apps for mobile devices now that can be hooked up to the OBDII port with an adapter - Torque for Android and one for iPhone was released late 2013. PA Soft for the PC is more expensive but offers in-depth scanning and real-time monitoring of performance parameters. INPA is also PC based and can be obtained for free on the internet, but is not the easiest to install or use.
Solidjake made a short vid explaining how easy it is to use a scan tool here
The error codes obtained will help in diagnosing the problem with your car.
A list of error codes with descriptions can be found at this website
BavAuto has a troubleshooting guide published in one of their regular newsletters. See post #10 in this thread Fuel pressure can be checked at the "tire-like" valve on the injector rail with a loaner gauge from autozone, etc. Pressures in the fuel pressure section below.
If you need to replace your starter, read this entire thread, which starts out with a good DIY and has some good tips towards the end.
For help with a faulty ignition switch, see "Problems Starting..." in the Electrical section above.
Engine running rough, stalls at idle, etc?
Misfire and Lean Code Troubleshooting P0171 P0174
Good thread here: Thread 1 discussing issues with fuel pumps, DISAs, CCVs, etc. Includes some DIY guidance
Fuel Pump Troubleshooting
When the key is turned to position 1 (on but not to crank position), you should hear a dull buzz from the passenger back seat area where the pump is. Checking for voltage at the pump connector - you should read about 5 volts at the pump for about 1 second when the key is turned on. A fuel filter with greater than 60,000 miles can restrict fuel flow and cause performance issues, and can strain the pump.
Fuel Pressure Specs
At prime (key on, no start) and while idling:
All engines except the S54 3.2L M3 - Fuel pressure 3.5 +/- 0.2 bar or 50.76 +/- 2.9 PSI Residual fuel pressure 20 minutes after shutdown - Fuel pressure >3 bar or >43.51 PSI
S54 3.2L M3 - Fuel pressure 5.0 +/- 0.2 bar or 72.5 +/- 2.9 PSI Residual fuel pressure 20 minutes after shutdown - Fuel pressure >4.5 bar or >62.2 PSI
Pressure can be checked at the Schrader valve (looks like regular tire air valve) on the injector rail (under the driver side beauty cover on the engine). Auto parts stores are reported to loan the pressure gauges.
Fuel Volume Specs
All engines 1.12 liter (1.16 qt) for 30 seconds at 12 Volts or while crank
Vehicles with ignition coils from a faulty batch may experience misfiring in one or more cylinders. The issue is identified via batch numbers of the problem ignition coils, as well as OBD-II diagnostics.
Camshaft position sensors
This is usually caused by either bad coils or a bad camshaft position sensor. Both are common problems, and usually they both 'throw a code' (triggering the service engine soon light). You can get your 'codes read' for free at any Autozone location to determine the problem.
There are two camshaft position sensors, one for the intake and one for the exhaust. The code should tell you which to replace. DIYs for the exhaust camshaft position sensor can be found here: Thread 1 Thread 2 Thread 3. A DIY for the intake camshaft position sensor can be found here: Thread 1.
TESTING THE CAM SENSOR: With a multimeter, in this thread.
Crankshaft position sensor
See this thread
Cracked intake tube
Another common problem is the intake tube elbow cracks. A DIY replacement can be found here.
Idle problems can also be caused by failure of the VANOS system. You can confirm this by seeing if your idle returns to normal after unplugging the VANOS wiring harness. BMW used an inferior material for the seal support o-rings and it is known to degrade considerably in as little as 40,000 miles, negatively affecting low end torque and engine smoothness in general. Beisan Systems (Beisan website has DIY including Valve Cover Gasket replacement)sells improved VANOS Viton seal kits for a DIY rebuild but even better Dr. Vanos sells completely rebuilt, blue printed and enhanced replacement VANOS units that also have Viton seals installed an are actually better than new BMW units for a very reasonable price.
Failed VANOS seals can cause fault codes generated by engine computer. In this thread (post #8) see how VANOS codes P0015 and P0014 were solved by the Beisan kit installation.
Also see this P0014 code solution thread where the root cause was the exhaust side vanos actuator (piston behind the solenoid) that was stuck and needed to be reset. Removal of the solenoid requires a 32mm deep, thin-walled socket, which is not easy to find. An e39er reported that a 1 11/32 shower valve socket will work and can be found in hardware stores for about $20.
What does VANOS RATTLE sound like? See the video here: https://www.youtube.com/watch?v=zAyQBiV5GbI
Secondary Air Control System Codes P0491 & P0492
The secondary air system pumps fresh air through holes in the exhaust valves to help the catalytic converters deal with the extra fuel in the exhaust vapor for the first minute or so on a cold start (when the engine runs rich, prior to settling to stable idle).
For troubleshooting and repair help of codes P0491 and P0492 see this thread by Starless
It has also been reported that the passages in the exhaust valves can clog and restrict the flow of air and some have had success with a seafoam procedure. WARNING: This will produce and unbelievable amount of smoke from the exhaust so be forewarned. See this link
Vacuum Fittings on Rear and Underside of Intake Manifold
See this thread for a good picture of the rear (post #2).
See this thread for pics of the underside (post #17).
Mass Airflow(MAF)Sensor Testing
If you get a code indicating a bad MAF sensor, you can try to diagnose by reading fuel trims with an appropriate scan tool and apply these tests with a multimeter, as discussed in this thread.
Horrible Burning Smell/Smoke coming from rear/passenger(US) side of engine (Valve Cover Gasket-VCG)
Most likely your valve cover gasket (VCG) has failed and needs replacement. Can usually confirm by inspecting the silver heat shield over the exhaust manifold and blotting a clean paper towel along the passenger side of the engine where the valve cover meets the head, looking for fresh oil. See VANOS failure above for procedures on the VCG replacement. It's a good time to refresh the seals in the VANOS at this time as the valve cover has to come off for VANOS service.
Oil light (yellow or red) illuminates during driving or after shutting the car off?
First, make sure you have enough oil. If you do, then your oil level sensor is defective. Please see this thread for DIY replacement information: TheYellowOilLightLink. If you don't have enough oil check your engine block for leaks. There are several known common gasket failures that could lead to an oil leak. The valve cover gasket is a common issue as is the oil housing gasket. The spark plug replacement section under other maintenance has a DIY on replacing the valve cover gasket. You can also follow the Beisan DIY  on doing a VANOS replacement as it is the same procedure, just ignore the VANOS section. The oil housing gasket section other maintenance has a DIY on replacing the oil housing gasket.
My car whines when I turn the steering wheel
You may need a new power steering pump. A great replacement DIY can be found here.
Electrical Connector Junction Box/"Where does this connector go?"
HERE is a good picture of the connector wires coming out from the junction box under the intake, with descriptions of each wire.
Sock Mod - Solve that power steering fluid splash problem
Power steering fluid splashing around your engine compartment? Watch this DIY for a track proven solution. jvr826 explains the aftermarket solutions available and brings you thru the step-by-step installation process.
What fuel grade should I use?
Your owners manual states you should use premium (At least 91 octane as measured by the R+M/2 method in the US). If you use a lesser grade fuel, your car will retard timing to avoid detonation, which will decrease fuel economy and reduce power. Premium fuel is even less of a price premium as gas prices increase since it's almost always either 20 or 25 cents higher than regular. Using regular might cost you more because you'll get less gas mileage but you will hear pinging (mostly in the summer) when mileage drops.
It is also recommended to add one bottle of Chevron Techron or BMW Fuel Injector cleaner every 3,000-5,000 miles or once per oil change.
Fuel Pump Problems
See Misfire and Lean Code (P0171 and P0174) Troubleshooting above in Engine section
Leak Detection Pump (LDP)/Charcoal Canister DIY
Usually you get codes specific to problems here. Check out this thread Also and the end of that thread there is a link with a tip for helping to get EVAP and CCM to set when they are stubborn.
What is the sensor/light by my headlight switch?
It is a light sensor which affects how brightly the on board computer and radio lights are displayed, based on how bright it is in the cabin. Test it out by getting in your car at night, starting it, turning on the headlights, then taking the flashlight out of the glove compartment and shining it at the sensor. The displays mentioned above should become much brighter.
What is the red knob below the rear-view mirror?
This is commonly referred to as the "clown nose". It houses a LED that flashes when the alarm is armed. For cars without the premium package (which includes the auto-dimming rear view), it also functions as the dimming lever- Just twist it!
How do I know if I've got leather or leatherette?
Please see post 95 of this thread over on E46Fanatics.
Interior trim removal/replacement
BMW service bulletins (search using Google)
- 51 16 260 - Glovebox Removal
- 51 24 005 - Removing and installing, replacing rearseat
- 51 43 075 - Removing and installing,replacing side trim panel, footwell on A pillar, right
- 51 43 150 - Removing and installing or replacing trim for left or right door pillar
- 51 47 000 - Removing and Installing, replacing the front (inside) left or right rocker panel strip
- 51 47 030 - Rear Right Door Sill Trim
- 51 47 131 - Boot Trim in Front of Spare Wheel Trough
- 51 47 151 - Removing and installing, replacing trunk wheelhousing trim
- 52 24 005 - E46 Removing and installing,replacing rear seat
- 52 24 010 - Removing Rear Seat Backrest
- 52 26 008 - E46 Removing and installing,replacing left,right sides of backrest on rear seat backrest
- 61 31 033 - RA Removing and installing light switch unit
More Information can be found in this Thread
- Instructions to remove the front seats can be found in this Thread
See Paul180's DIY here.
OEM ///M dead pedal and aluminum pedals
Available for left-hand-drive only. See Paul180's DIY here.
OEM ///M steering wheel
If you're looking to replace your steering wheel or take it off completely follow Paul180's DIY here.
Red Sharpie Gauge Needle Mod
If you're looking to make your gauge needles red/orange like the ZHP verson refer to Solidjake's DIY video here.
Angel Eye On/Off Switch
If you have aftermarket angel eyes installed you can fabricate a switch that can be placed in the interior to turn on/off the angel eyes at any time. Please refer to SlimKlims Angel Eye Switch DIY 
Third Brake Light Removal
If you need to remove your third brake light for cleaning or repair please follow Jcourcoul's DIY guide here.
- Rear deck - see here for a solution.
- Middle brake light
- Rear tweaters
- Cables inside front doors
- Toolbox in trunk lid
- Warning triangle
- Front seat plastic trim covers
- Through-loading system latches
- Safety belt clips
- Worn out spare tire cushion
- Exhaust shields
My window doesn't go all the way up/down or makes bad noises (WINDOW REGULATOR)
This is almost always the window regulator, a known failure point. Here are some do-it-yourself replacement instructions: Thread 1 Thread 2 Thread 3 (BEST "zip-tie"). Here and here are other posts with good tips. Additional observations here. Removing the door panel on coupes - there are three screws in the door handle, one behind the circle cover in the open/pull lever cavity, and one behind the little airbag badge. Then start pulling at the lower panel corner just like on the sedans. Inside the door, the window is held to the lift bracket with an external torx bolt (E7?), vs. a low-profile hex head bolt on the sedans.
It's believed that the windows sticking to the rubber seals when closed stresses the plastic cable-holder on opening, and this can be lessened by treating your seals so they don't stick - "gummiflege" or glycerine. Also, lubing the lifting tracks on the regulator can help - some say white lithium grease but the original grease is a thicker, sticky grease (probably waterproof since that part of the door sees water), which may be sold as a "waterproof grease" at auto parts stores. Some recommend a squirt of a silicone-type of oil at the top of the window channels near the top of the door. Less binding, less stress on the plastic cable-holder or zip-tie fix. Careful with the foam vapor barrier, cut the tarry adhesive with a thin flexible knife and heat with hairdryer to make more pliable/ensure good reseal. You can buy more of the adhesive "ribbon seal" at auto parts stores if you need to refresh. Also don't lose the felt grommets off all the plastic pop rivets for the door panel.
My window auto-up/down does not work
You can reset the window auto function by:
- Turn the key to the ON position but do not start the car
- Roll the windows all the way down, THEN roll them all the way up and HOLD the switch up for an additional 5-10 seconds.
- Turn the key off.
To reset sunroof if won't close, hold button in up position (towards roof) for 20 seconds, then push forward. This may resolve problem.
When screwing the glass back on to the slide mounts be sure to push the glass up slightly so that the screws do not rest on the slide mount, it will not allow enough clearance for the roof to open and close properly. You will most likely also notice a large gap due to the sunroof sitting up to a 1/4" lower then the top of the roof.
- Main article: Navigation
Versions of the NAV in the E46
- The MK2 NAV system (CD based) was available from start of production to 05/2000 production date E46s
- The MK3 NAV system (CD based) was available from 06/2000 to 09/2002 production date E46s. In 2002, it received a 16x9 widescreen display (with a cassette behind it)
- The MKIV NAV system (DVD based) was available from 10/2002 production on. It is a 16x9 widescreen display with either a cassette, minidisk or CD player behind it)
Exterior / Body
There are many wheels available for the E46. The bolt pattern is 5x120, 72mm center bore, and the offset for both front and rear need to be between +35 and +50, and fitting the outer limits of that range will depend on selected tire size. 323/325/328s can use 16" or bigger wheels. The 330s must use 17" or bigger wheels to clear the brakes, with two exceptions - there are two known 16" wheels that will fit over the 330s brakes: the ASA JH3, and the 16x7.5 AT Italia Type 5.
Most E46s with the sport package came with staggered wheels and tires; that is, the rears are wider than the fronts. This /negatively/ affects performance because it encourages understeer. Of course, understeer is safer than oversteer, so that's the way BMW err's.
The widest non-staggered size that you can run seems to be 255/35/18. jvr826 has these on 18x8.5 wheels with a +42 offset and KrisL has these on 4 rear ZHP wheels (18x8.5 with a +50 offset).
Rear M3 wheels will NOT fit on a non-M3 (the rear M3 offset is +24), but the fronts will. You can buy four FRONT M3 wheels and put them on all four corners of a non-M car. If you're wondering "what it would take to get rear M3 wheels on the car"... it would take thousands of dollars in body work to get the fenders wide enough - its just not worth it when there are many great aftermarket wheel designs that will look and fit great, as well as giving you a nice staggered look, if that's what you're after. Check out the offerings by umnitza.com, jlevisw.com, europeanautosource.com, etc.
E39 5-series wheels have a different center bore/hub size and therefore should not be used. For standard BMW bore/hub size reference please see this information.
When removing alloy wheels, note that a galvanic reaction may have set in between the alloy and the wheel hub, "sticking" the wheel to the hub. To encourage the wheel to come off, jack the car up with your preferred method, so the tire is approximately 1" off the ground. Using a heavy (e.g. sledge) hammer, place a block of thick wood (e.g. 4 X 4) behind the wheel. Hit until the wheel is dislodged. You may have to alternate sides of the wheel.
Before replacing the wheel, smear a thin layer of quality lithium grease on the wheel hub landing. This will make removal of the wheel easier next time.
For more information or other questions, please post them in the TireRack sponsored Tire forum here at Bimmerfest.
|Front or rear or both?||Wheel size (Height x Width)||Offset||Car lowered?||Tire size||Sedan or Coupe?||Rubbing?||Forum name||Notes|
|Both||18x8.5||50||Yes||255/35/18||Sedan||No||Bimmerfest: KrisL||Rear OEM ZHP wheels on all 4 corners, no problems!|
|Front||17x8.5||40||No||225/45/17||Sedan||No||E46Fanatics: phlfly||I have style 68 BMW wheels on 325i touring/wagon. The front 225/45 ZR17, the rear 245/40 ZR17. It fits perfect. I don't know offest.|
|Both||18x8.5||38||No||225/40/18||Sedan||No||Bimmerfest: louis1978uk||no rubbing still on standard shocks will know for sure when my coilovers arrive early next week|
|Front||19x8.5||35||Yes||235/35/19||Sedan||No||E46Fanatics: mimalmo||Dunlop SP Sport Maxx tires|
|Front||18x8.5||40||Yes||235/40/18||Sedan||No||E46Fanatics: [email protected] SW||BBS CHs, 18's non staggered all around. Very conservative setup but worked well.|
|Front||18x8||35||No||225/40/18||Sedan||No||Bimmerfest: AlboBmw||I put ZHP replicas wheels the 135m style. They weigh 24 lbs each, and the tires I run (Yokohama S.Drives Ultra High Performance Summer) weigh 23 lbs each. Wheels are TUV approved. No rubbing.|
|Both||17x8||40||No||225/45/17||Coupe||No||Bimmerfest: mccreary||OEM Style 44's with Blizzak WS-60's for winter. ASA AR1's with General Exclaim UHP's for the summer. Both sets of wheels are tires are the same dimensions, except the offset on the OEM style 44's are 47mm.|
|Both||17x7.5||38||No||225/45/17||Coupe||No||Bimmerfest: Fast Bob||This is my winter setup, running Dunlop Wintersport M3s, on 17-inch Borbet Type Es. Conservative sizing, no rubbing.|
|Both||16x7.5||36||No||205/55/16||Sedan||No||Bimmerfest: nattyderek||Winter setup. ASA JH3 rims w/ Dunlop Wintersport 3Ds. One of only a few 16 inch rims that will clear 330i brakes. Work great for winter wheels.|
|Both||18x8||40||No||225/40/18||Sedan||No||Bimmerfest: jryguyi||OEM style 135 on Cooper Zeon Sport Tires|
|Front||19x8.5||40||Yes||235/35/19||Coupe||No||E46Fanatics: AL330CI||Will be going to a square setup 18x8.5 & 255/35/18 in the future.|
|Rear||19x9.5||35||Yes||265/30/19||Coupe||No||E46Fanatics: AL330CI||Used to rub inside tire edge on passenger side going over large dips at highway speed. Rubbing gone after installing Meyle HD RTAB & Turner RTAB Limiter.|
|Both||18x8.5||40||No||235/40/18||Sedan||No||E46Fanatics: bmw3.0l||No rubbing at all.|
|Rear||18x8.5||38||Yes||255/35/18||Sedan||No||Bimmerfest: PhilH||Suspension is Bilstein PSS10|
|Both||18x8||37||No||225/40/18||Sedan||No||Bimmerfest: Reekinghavoc702||running Goodyear GT great tires!|
|Both||17x8||40||No||225/45/17||Sedan||No||BFC: LX-biker||OZ ultraleggerra wheels/Yokohama S-Drive tires on 325XI; had alignment off spec, now summer tires are noisy. Did not notice aligment problems with OEM wheels.|
|Both||16x7.5||40||No||205/55/16||Sedan||No||E46Fanatics: martinm||Summer setup, General Exclaim UHPs|
|Both||17x8||35||No||235/45/17||Coupe||No||E46Fanatics: bimmer654||Still having fitment a issue where I am experiencing vibration. Never had this issue with the oem wheels. I'm on my second set of TSW's which are made in China, so no surprise on quality issues. Most likley will be returning these for another brand or put oem's back on.|
|Front||19x8.5||40||No||225/35/19||Sedan||No||E46Fanatics: Lexman||Lm reps, needs to lower my sedan zhp soon, preferably UUC springs only with OEM shocks.|
|Both||18x8.5||35||No||225/40/18||Sedan||No||Bimmerfest: CaptainTrap||I am running Velocity Motoring v710s from jlevisw.com General Exclaim UHP tires mounted.|
|Front||18x8.5||40||Yes||225||Sedan||No||Bimmerfest: Keyser Soze||O.Z. Ultraleggera's|
|Front||18x8.5||40||No||235/40/18||Coupe||No||Bimmerfest: JonS2004330ci||2004 330ci ModBargains HyperBlack CSL Replicas Staggered setup: Fronts running 18x8.5 ET40 wheels Front Tires: Bridgestone Potenza RE760 Sports Front Tire Size: 235/40/18 Stock BMW Sport suspension NO RUBBING!|
|Rear||18x9.5||45||No||265/35/18||Coupe||No||Bimmerfest: JonS2004330ci||2004 330ci ModBargains HyperBlack CSL Replicas Staggered setup: Rears running 18x9.5 ET45 wheels Rear Tires: Bridgestone Potenza RE760 Sports Rear Tire Size: 265/35/18 Stock BMW Sport suspension NO RUBBING!|
|Both||18X8.5||45||No||225/40/18||Coupe||No||Bimmerfest: TurfGuy||General UHP on Elbrus 5 spoke|
|Both||17x8||35||No||235/45/17||Coupe||No||E46Fanatics: neo bmw||I dont exactly have a radical setup or anything. The 35 offset is the main difference from the stock offset of 47, that's about a half inch according to my tape measure. my wheels are 1/2 inch wider than stock and I only went up one size (225 to 235) on the tire width. Stock size for my car is a 17x7.5 wheel with a 225/45/17 tire.|
|Both||19x8.5||40||No||235||Sedan||No||BFC: ninehundredf||i love em!|
|Both||17x8||40||No||225/45/17||Sedan||No||Bimmerfest: Duke W||ZSP sport package on stock suspension. 17x8 Borbet Fs with 225/45/17 Bridgestone RE-01Rs.|
|Both||18x8||40||No||225/40/18||Sedan||No||Bimmerfest: jack_ski||Sport Package.|
|Both||18x8.5||35||No||225/40/18||Sedan||No||Bimmerfest: Little Bear||Had rubbing up front until I fixed my crowned strut towers. Not sure if the 35 offset makes the car wander more on bumps & such, but think it might.|
|Both||17x8||40||No||235/45/17||Sedan||No||Bimmerfest: mybavauto||have put 1000miles on them, still able to whip around turns now as i did the first day i had them mounted.|
|Both||18x8.5||+40||Yes||225/40/18||Sedan||No||Bimmerfest: SteveThePirate||Car is lowered with adjustable height ST V1 coilovers. There is, so far no problems with rubbing of the fenders. Wheel Style CSL Reps.|
|Both||18x8.5||42||Yes||255/35/18||Coupe||Yes||Bimmerfest: jvr826||Running Michelin PS2 I had no need to roll my fenders, tho there was very minor rubbing under compression. Once I switched brand and model of tire, fender roll and clipping of the plastic fender liner was required on the passenger rear to avoid rubbing the sidewall of the tire. I still have rubbing deep into the fender well metal on BOTH sides with my setup, but as the tires wear down, it is less of an issue, yet still there. Rubbing occurs under suspension compression when carving canyons and driving enthusiastically. Freeway trips with no load are fine.|
|Rear||19x9.5||45||Yes||255/30/19||Sedan||Yes||E46Fanatics: mimalmo||Dunlop SP Sport Maxx tires. Lowered on KW V2 coilovers with a little tire tuck both front and rear. Rear fenders had to be rolled. No more rubbing now.|
|Both||18x8||35||No||235/40/18||Sedan||Yes||Bimmerfest: jhowe1||large dips in road at higher speeds the rears slightly rub. not lowered, just oem sport package suspension.|
|Rear||18x9||40||Yes||255/40/18||Sedan||Yes||E46Fanatics: zx5rider||had to raise the back a lil bit|
|Rear||18x10||40||No||225/40/18||Sedan||Yes||E46Fanatics: mcr_driver||car was on stock ZSP suspension, i think rubbing issue was due to stock suspension being too soft or shocks could have been old. did a slight rill to help offset rubbing but i honestly think a solid coilover kit would have fixed my issue for good|
|Front||18x8.5||30||Yes||225/40/18||Sedan||Yes||Bimmerfest: MalibuMafiaV||The tires did rub. I had to get the rear fenders trimmed off in order for it not to. I recommend never getting the offset of 30:) go higher.|
|Both||18x8.5||38||Yes||255/35/18||Coupe||Yes||E46Fanatics: MrMotorwerk||Toyo T1R and Yokohama dont rub as much, Ended up rolling all the fenders which helps, especially when looking for better tires.|
|Rear||19x9.5||40||No||245/35/19||Sedan||Yes||E46Fanatics: Lexman||Only rubs a little when going to fast on dips. Still have to do some fender rolling soon with a nice spring set up only to drop my ride. Shocks are in great condition so I don't see the need to replace them.|
|Rear||18x9||40||Yes||255||Sedan||Yes||Bimmerfest: Keyser Soze||O.Z. Ultraleggera's Some rubbing on the rears with new tires, haven't heard it in months unless people are riding in the backseat, then it can still rub. I am too lazy to take JVR's advice and take the rears off and look for the spot on the plastic where it rubs and cut it out. lol|
Jet Fockin' Black
Warining: Don't make your tires JFB! Link.
The aerodynamics packages installed on E46 cars from the factory varied according to model year, body style and trim level. Flexible ordering/optioning ensured that customers in European and most world markets typically had a variety of aerodynamics packages to choose from.
In the US market, a more specific set of guidelines can be used to determine the aerodynamics package installed on a particular car:
- Prefacelift sedan (1999-2001 323i/325i/328i/330i)
- Prefacelift coupe/convertible (2000-2003 323Ci/325Ci/328Ci/330Ci)
- Prefacelift BMW Accessories Aero Kit (optional dealer installed accessory kit for prefacelift cars; very rare)
- Facelift sedan (2002-2005 325i/330i)
- Facelift coupe/convertible (2004-2006 325Ci/330Ci)
- M-tech I (2001-2005 330i with ZSP/Sport package, sedan only including prefacelift)
- M-tech II (2003-2005 330i with ZHP/Performance package / 2004-2006 330Ci with ZHP)
- M3 (2001-2006 M3, all)
In most world markets, the M-tech aerodynamic kits were associated with M-sport equipped cars. The original M-tech I design was superseded by M-tech II during later production years. In the US market, M-tech I was found on ZSP equipped 330 sedans regardless of production year and M-tech II was only available with the ZHP options package.
Many aftermarket body kits of varying qualities are available for the E46. The most popular OEM retrofit kit is M-tech II (standard equipment on ZHP). You can purchase it from your local dealer or online from somewhere like www.bavauto.com for $900-1000. They come unpainted, so you will have to get it painted by a body shop.
Other body kits may be bought from Bimmerfest sponsors. This includes a wide range or front and rear bumpers, side skirts, vented hoods and other aftermarket parts. Fitments of these parts are made for almost all models, sedan, coupe and convertible.
How to fit M3 body parts on a Non-M Car
Warning: this is classified as /ricey/ and may result in ridicule here on Bimmerfest :). Please see This thread over on E46Fanatics.
Where are the jack points on the E46?
Facelifting a pre-facelift Sedan
Information can be found here.
Exterior trim replacement
Here is a DIY how-to.
Some discussion on this and how easy to fix in this thread.
Halogen Headlight Bulb Replacement Tip
Make sure you put the bulb into the socket oriented the same way as the one you're replacing. If it's off 180 degrees, you may not be able to remount the socket into the lens housing. If you have difficulty remounting with the new bulb, try taking the bulb out of the socket and rotating 180 degrees, then remount the socket to the lens housing.
Clear turn signals
Your best bet is to stick with OEM if you want 'clear corners'. Aftermarket lenses are of varying quality and may leak. The OEM clear corners are manufactured by ULF and can be purchased by many companies such as www.bekkers.com, www.bavauto.com, etc.
DEPO lenses used to be poor quality, but recent reports are promising and have shown that the quality has improved. They can be purchased much cheaper than OEM from places like www.jlevisw.com.
Installation is very easy... thanks to my330i.com for these DIYs: Front/side install DIY for 2002+ Sedan Rear install DIY for 2002+ Sedan Front/side install DIY for 1999-2001 Sedan Rear install DIY for 1999-2001 Sedan
Another DIY guide can be found on the forums: 
Facelift coupes use a #7440 type bulb for the front turn signals, not a #7507 as indicated on Sylvania's Lamp Guide.
Angel Eyes or Demon Eyes are lighted rings around the headlights. They are standard on E39 (and newer) 5-series cars as well as E90 (new 3-series cars). Umnitza (www.umnitza.com) makes a kit (Predator Chromium) that can be retrofitted into existing headlights. For prefacelift cars, the headlights simply snap open. Facelift headlights must be baked in an oven to be opened up.
There is a new brighter kit out called Predator Orion V2 - available exclusively at Umnitza.com More information can be found here: POV2
Another forum sponsor, European Auto Source, now sells a very similar product for less money - the MYCARR angel eyes. A comparison between these and the Predator Chromium kit can be found here: My Carr Angel Eyes
Your best bet for installing projector Xenon lights in a car that does not have them available is a plug-and-play headlight replacement such as the Umnitza ( www.umnitza.com ) Projector46 with Orion V2 kit. They can even be purchased with angel eyes pre-installed. They offer a solution that does not require any reflashing.
Complete used OEM HID assemblies are also available via Ebay, forum "for-sale" sections, and other sources. Typical prices for a complete set of used (but intact and working) HID headlights range from $400 to $600. Purchasing brand new assemblies via the dealership or an importer is not recommended as the price is generally exorbitant (e.g. $1,100 -- per side). You not only need the lights, but you also need a new LCM (light control module) and it coded to your car. This can add another few hundred dollars.
You may disable the "headlight out" warning by pulling fuse #32. Note that this will not disable the actual light out warning (which would occur if the lights were switched to the on position and one or both failed to activate), only the passive warning which is only triggered when the headlights are set to be off.
LED Tail Light Retrofitting and Troubleshooting
If your blinker stops working or dims considerably, many have had success restoring function with some light soldering on one of the resistor packs. See this thread over on E46Fanatics.
E46 High Intensity Discharge (HID) Xenon lights use D2S bulbs. The bulbs come stock in 4300K color temperature, however aftermarket bulbs are available in higher color temperature colors from aftermarket suppliers.
Are your Bi-Xenon headlights dimmer than you last remember?
In some cases, the inside of the headlamp projector bowl may be burnt and/or discolored.
One option is to replace the headlamp projector bowls. Checkout eBay or similar as the ZKW projector bowls are not available as replacement parts, and the entire assembly lists for approximately $1,200 -- for each side.
If you find a bowl, a DIY to replace the headlamp projector bowls for ZKW Bi-Xenon headlights is shown in this thread.
Another option is the Lightwerkz TFX projector upgrade. This involves removing your headlamp assemblies and sending them to Lightwerkz in New Jersey to have Infiniti and Acura hardware retrofitted into your headlamp assemblies. Note that this does not affect the HID bulb or the auto-leveling motor. More information is available at = this thread.
Are your Xenon auto-leveling headlights pointing down?
The plastic arm for the front self-leveling sensor is likely broken. It's visible with a flashlight by turning your wheels all the way to the right and looking above the right control arm. It's possible to epoxy it back in place (I actually wrapped a zip tie around the whole arm, then used epoxy liberally around the whole thing). The part is what bolt #4 touches to in this picture. If your late-model self-leveling headlamps are made by ALS/Bosch, the inner pivot next to the levelling solenoid mechanism in the headlamp is prone to breakage. With care and patience you may be able to wire up the broken part as a workaround. This thread may help to understand the issue.
It is also possible for the link from the front lower control arm to the leveling sensor to become inverted if the suspension is relaxed, such as when changing a tire. When the suspension is reloaded the arm folds down and tells the sensor the front of the car is pointing up. This may not be readily apparent during a visual inspection. The link should be vertical, rather than horizontal. See this thread for more information: http://www.bimmerfest.com/forums/showthread.php?t=781369
- Euro OEM split mirror. The outer third of the mirror is convex, eliminating your blind spots. For the coupe & convertible, the part number is "51 16 8 247 131" (left) and "51 16 8 247 132" (right). For the sedan, the mirror is square, so it's the same part number for both the left and right (51 16 8 250 438). Generally, you only want to order a left side mirror on a left drive car since the right mirror is already convex. Please see the "parts" section of this Wiki for where to order BMW parts. More info can be found here
- Black grille. www.bimmian.com (among other sites) sells black kidney grilles. On performance package cars (which have gloss black window trim), the kidney grille is the only chrome on the car; therefore, it's a common mod to replace it with a jet black grille.
- Front "blank" bumper strip (sedan/wagon only). BMW part # 51-11-8-195-304 replaces the standard front license plate bracket, eliminating it.
- BMW (Westfalia) hidden tow-bar/towing hitch
- M3 CSL carbon fibre trunk lid
Door Lock Cylinder Broken?
Once you get your door open, the cylinder can be replaced or rebuilt fairly easily. It's held in by one allen-head screw. See this thread for rebuild info.
Getting an odd rattle from the rear?
If your car was made before October 2002 production, the rear springs have a tendency to break. You can remove a wheel to see it. There's a TSB on it here.
Yet more knocks from the trunk?
The sound deadening material on the spare tire compartment may be damaged or missing, causing the wheel of the spare tire to rattle against the metal, which can be solved with a sheet of rubber. Here is a quick DIY thread by Jcourcoul on how to do that.
Strut towers 'mushrooming'
Depending on road conditions and how hard a vehicle is driven, the bolts fastening the front shocks to the strut towers are prone to bending outwards over time due to a lack of re-inforcement at the top of the shock towers. This can affect your alignment and handling. There are two cures for this problem: Install the stronger strut tower spacers from the 4x4 (See DIY here), or install a (M3) strut brace between the two shock towers, as shown here.
BMW Performance Catalog
BMW has released their own line of performance parts for the E46. Many of the ZHP parts are available for the non-ZHP 330. THere are also shift knobs, brake rotors, etc. A scan of the catalog can be found here
Tischer BMW is offering great deals on the parts in the catalog. You can see the prices and order online here
BMW Performance rotors
Better pictures of the brake rotors and some great brake changing tips can be found in this thread
BMW Performance intake
Straight line performance / Horsepower
The E46, like most BMWs, gain very little from typical performance modifications. If you were to buy a cold air intake, software, headers, exhaust, and underdrive pullies, you'd be lucky to gain 20-25hp and you'd be $1500-3000 poorer. Forced induction (supercharger or turbocharger) is the only solution for real power gains.
Forced Induction - Turbo and Supercharging
Kits are available from companies like VF Engineering, Active Autoworke, Technique Tuning, Dinan, and ESS. They typically run $5000-7000 + installation and can usually give you about a 50% hp/torque boost over stock. Some recent discussion here, with good info starting at post #9.
How to avoid a CEL when installing aftermarket headers
Here is a thread describing solutions.
A shorter differential is the only significant performance booster without forced induction. A differential swap is best performed by a shop ( preferably performance-oriented). Switching to a shorter (higher-numerically) ratio allows the engine to get into the fat part of it`s power band more quickly because it`s spinning a bit faster in any given gear (kind of like your old 10-speed bike which would accelerate much faster on the small front sprocket as opposed to the big one). For example, changing from a 3.07 gear to a 3.46 gear would give the car lots of extra grunt out of second-gear corners, and would reduce the need for downshifts when passing, etc. The downsides are higher engine RPMs(noise) at highway speeds, and slightly reduced gas mileage.... but with a MUCH higher "fun factor".
Here is a great thread walking you through swapping your own differential.
How can I find out what differentials are compatible?
Follow this link for more information.
The input flanges from the (323-325) differentials are different than those in the (328-330). You may have to swap input flanges depending on where you are getting your diff. here is a great DIY on swapping the flanges.
While BMWs are known to be great handling cars, there are certainly plenty of suspension upgrades available:
- Powerflex control arm bushings (www.bimmerworld.com) will make turn-in a bit crisper
- Rear trailing arm bushing limiters (www.motor-force.com) will reduce excessive toe change under cornering force
- Sway bars (many options such as UUC's SwayBarbarians, www.uucmotorwerks.com) are often referred to as the best suspension mod bang for the buck. They actually make your suspension LESS independent, but greatly reduce body roll with very little tradeoffs.
- Shocks/Struts and springs are available. If you have a car without the sport or performance packages, simply swapping sport/performance package suspension bits will help quite a bit. If you want to go further, consider adjustable shocks, lowering springs or full coilover kits from GroundControl, Tein, or TC Kline.
UUC Swaybarbarian install
Check out Paul180's DIY here.
UUC Sachs performance suspension install
Check out Paul180's DIY here.
M3 Strut tower brace install
Check out Paul180's DIY here.
Check out the chart from UUC here. This shows you how to change the feel of your car by increasing or decreasing stiffness in suspension components, and adjusting tire pressure.
Removing weight from an E46 improves all performance aspects as well as mileage, but often at the expense of luxury and comfort items. Here is a great thread about what you can remove.
This is where the biggest "bang for the buck" modification is - and you can 'transfer' this mod to any vehicle you drive! The BMW Car Club of America's local chapters hold autocrosses, car control clinics, and high performance driving schools. You think you're a good driver - until you go against some of the BMWCCA's instructors. It's truly a humbling experience that shows you how much skill is truly involved in going fast.
Steering & Suspension
Shocks and struts
smithnet.ca has a write-up for replacing shocks and struts here
Springs can break, especially in the rear and may not be easily detected. A clang sound or creaking when cornering or going over bumps can be an indication. See this thread for discussion, with a good DIY video linked in post #39.
What was the steering retrofit?
BMW marketing had feedback that said that their cars took too much effort to turn the wheel in slow speed situations, i.e. parking. BMW modified the steering rack and system to decrease the steering effort. Those owners who have had extensive experience with E36's (previous generation 3 series) or pre June 2000 cars have stated that there was also a resulting loss of road feel through the steering wheel. Many of these board members have dubbed the "new" steering feel equipped cars as the "Ultimate Parking Machine".
Various owners have stated that the only E46's spared this steering boost and loss in road feel are those equipped with the all wheel drive option (i.e. Xi's).
Current rumors state that the steering rack was modified again starting in Jan. 1, 2001 and that the "old" steering was phased in. Some E46s produced between Jan and April may or may not have the "old" steering. If you are unsure, check out post April 2001 cars and compare steering feel. See these posts from "Ginger" and Jon S. Post 1 & Post 2. Those with post-April 1, 2001 have stated that the steering feel was indeed not pre-June 2000 feel, but somewhere in between the "new" (June-Dec 2000) and the old (pre-June 2000). The post April 2001 steering has been dubbed as the "new-new" steering. This change was a direct result of feedback through bimmer.org members posting on the E46 board and direct contact with BMW NA. So our voice does count!
So the current terminology is:
- "old" feel: pre-June 2000 build
- "new" feel: June through December 2000 and some Jan-April 2001
- "new-new" feel: post April 2001
- "retrofit" feel: early retrofit "pilot" run participants have stated that the retrofit feels somewhere between the "new-new" and the "old" feel.
In response to consumer feedback, BMW NA initiated a program to satisfy owners of MY2001 E46s who prefer less boost in the power steering system. These owners maintain that a loss of 'feel' was associated with the newer systems which had more boost than MY2000 and earlier E46s. Intitially, BMW NA maintained a list of owners who would be interested in changing their steering racks for systems with less boost. People who have called in to have their name added to a list of persons interested in a retrofit back in Jan/Feb began to be contacted starting the week of April 16, 2001 en masse. BMW NA is going through the list and contacting those with 323/325 and 330's that were produced between June and December 2000, and is offering a one-time free-of-charge changeover to a less boosted steering system.
BMWNA has been very clear on the statements to those contacted. They typically cover the following items:
- Steering rack and components will be replaced with pre-June 2000 components at no charge.
- You have your choice of BMW centers to install the retrofit.
- BMWNA will contact your chose center to give them the details and parts needed for the retrofit. BMWNA requests a couple of days before you try to schedule an appointment with your center.
- BMWNA makes it very clear that the retrofit will make steering more difficult at lower speeds.
There has been some confusion as to whether June-Dec 2000 325's and post Jan 2001 cars with "new-new" feel were eligible for the retrofit. Latest news is that the post Jan 325/330's are eligible due to the phase in started in Jan 2001. "New-new" feel cars might be and will be evaluated on a case by case basis according to some sources.
You can find alignment specifications at these links:
- TIS Alignment Ballasting Specs
- TIS Alignment Ballasting Specs (Convertible)
- Thread 1
- Thread 2
- Link 1
Car doesn't feel as crisp as it once did?
Control arms and control arm bushings are common failure points in the E46. Control arm bushings can last as little as 40-60k miles with the control arms themselves not far behind. The most common symptom is the steering not feeling as crisp as it once did; however, there are other worse symptoms such as the car wanting to turn when you jab the brakes.
OEM Bimmer Parts is a Bimmerfest sponsor that sells control arms and control arm bushings. BimmerWorld is a retailer that sells aftermarket arms and powerflex (stiffer) bushings. For the AWD XI models, the control arms, bushings, etc are different than the standard RWD models, and require a slightly different replacement procedure.
Here are control arm replacement DIYs:
Do you experience excessive 'play' in your steering?
ZHP Shift Knob
Paul180 has a DIY for installing the shorter ZHP shift knob here.
Short Shift Kits
The UUC (EVO3), Rogue, and B&M shift kits are the most popular short shift kits for the E46.
Here is a thread with instructions on installing the UUC short shift kit in an Xi (AWD)
Paul180 also has a DIY for installing the kit on a 330i here.
If you're budget minded, understeer.com has an line of modified BMW levers to suit your car.
Clutch Delay Valve
The clutch delay valve is a small valve in the clutch line that restricts clutch fluid flow. It's designed to prevent shock to the transmission if the clutch is dropped. The bad part is that it makes the clutch feel vague and can make it difficult to pull off smooth shifts for experienced manual transmission drivers.
Note that installation of a restricted CDV was not made on all manual cars. There are some that do not have one, some that do have one without restriction (same as the delete version) and then a lot of cars that have a restricted CDV. Seems that earlier E46 do not have it and it was phased in sometime in 2001 built dates.
There are two choices: Remove the CDV completely (the two ends of the clutch line will screw into each other, requiring no parts) or replace the CDV with a drilled-out version, eliminating the restriction. People use the drilled-out version to avoid dealer hassles in case a transmission warranty issue arises.
After replacing or removing the CDV, you do need to bleed the clutch line.
More information, as well as where to purchase a drilled-out CDV, can be found here.
Paul180's CDV replacement DIY can be found here.
Another cause of poor clutch feel is that the factory clutch stop (the plastic piece that prevents the clutch from depressing any further) is too low; that is, you don't need it to go down as far as it does. You can purchase clutch stops from many aftermarket companies (UUC, Rogue), but I made my own. More information can be found here.
A DIY for installing UUC Transmission mounts can be found here.
Auto ----> 5 speed conversion
Neil1138, a regular on E46Fanatics, released a great DIY on how to perform a complete manual transmission conversion on your E46! Included inside are detailed mechanical procedures and even a complete coding section required to finish the transformation! Link here.
- Early automatic transmissions are a weak point in the E46. The first symptom of a failing transmission is the inability to engage reverse gear. This issue plagues early E46 owners including 323/328 owners. If you have a 323/328 and think you have the no-reverse problem, check out this thread. It has information on how you might be able to fix your no-reverse issue if you have a GM transmission: http://forum.e46fanatics.com/showthread.php?t=706809
- Another GM "no reverse" thread can be found here: here
- If you have an SMG/SSG transmission, there is a seal that often fails. A machine shop in Malaysia has made a better replacement... check [this thread http://www.bimmerfest.com/forums/showthread.php?p=3683902] for details.
- Discussion and possible fix of p0720 error (output speed sensor circuit) can be found here
- Resetting TM adaptations can sometimes help with fault codes. You can reset the TM to the factory settings by doing the following:
1)Insert the Key into the ignition (DON’T HOLD THE BRAKE). 2)Turn the key, just so the car electronics start and show the Engine light is on. (Don’t START the Engine). 3)Press and HOLD the accelerater all the way down for 25 seconds. 4)After those 25 Seconds, proceed to Starting the Engine and drive your car.
If done correctly you should feel the car to be more responsive and shift better as it resets the memory in the transmission.
Pressure valve upgrade
There is a theory that with time original pressure regulator valve will wear out and cause oil pressure spikes. It has been speculated that oil pressure spikes will cause torque converter seal to blow and/or cause torque converter bearing to spin out and pop out. Upgraded pressure regulator valve is available from TransGo, part number 5HP-19-PR. Installation of upgraded pressure valve can be done without removing transmission from the car. Keep in mind that worn out pressure regulator valve might damage inside walls/bore. Great example of worn out pressure regulator valve.
HVAC - Ventilation & A/C / Climate Control
I hear a beep at 37 degrees fahrenheit (3 degrees celsius). Why?
All BMWs will beep once the temperature reaches (or is below, if you're just starting your car) 37 degrees fahrenheit. This is to warn of the possibility of black ice. A dealer can disable the chime. It's a bit of an annoing feature and always sends people thinking "What's wrong with my car now ...." This question comes up on the forum every winter :)
Switching between Fahrenheit and Celsius
To switch between F and C on the auto climate control, press the AUTO and FRONT DEFROST buttons at the same time, then release.
Erratic fan speed?
- The most common problem with the climate control system is a bad final stage resistor. The symptoms of this are erratic fan speed (fan blowing at full speed while the display shows a low fan speed). You can find replacement information here
- FSU (aka blower motor resistor) replacement pictorial DIY by Starless is here: click here
- If the fan speed DOES match the graph display, but it is constantly/incorrectly adjusting speed *OR* if the climate control unit won't turn off or on, you MAY need to replace the climate control module (IHKA). In the case of constantly/incorrectly adjusting fan speed, try replacing the final stage resistor first.
- If your climate control won't turn off OR on, the problem is likely the climate control module (IHKA). If the problem is intermittent, you can usually 'reset' it by pulling out the appropriate fuses for a few seconds.
- To test electrically for a bad fan vs. bad fsu vs. bad module, see this post
Does your driver's side A/C blow colder than the passenger side?
As wrong as this sounds, that means the car is low on refrigerant (R134A). BMWs have a "dual" A/C system that 'favors' the driver's side when the refrigerant runs low. You should be able to pick up a R134A refill kit at a local auto parts store.
Thread with high/low side pressure chart here, as well as a link to a/c troubleshooting.
A/C Evaporator/Expansion Valve DIY (you won't believe the pics)
See this thread
Musty(Gym Sock) Smell from Vents?
See this thread
Getting constant heat even when the AC is on?
Your heater valve could have failed open, constantly heating the air inside the car. The valve opens to flow hot coolant through the heater core for heat in the car, but should close when heat is not needed. Here's a good DIY for replacing this part: Thread 1
If it's just warm air from some vents (and NOT the passenger side scenario described above indicating low refrigerant) it could be a problem with the control flaps inside the vent system. Sometimes the vent flap motors (controlling the flaps in the vents that route air to footwells/dash/windshield etc.) will fail or the flaps break. A fuse for the flap motors can blow too.
I hear a "cricket/screeching" from my vents
The climate control fan either becomes unbalanced due to accumulation of dirt/dust, gets something caught in its housing (like a leaf or bug), or has worn out its bearings (or possibly just the electrical "brushes" that make it spin). For DIY and other info., see this thread.
RealOEM offers an online part number database for all BMWs. Look up the part number for the part you need here: RealOEM or BMW Fans. With the part number in hand, you can now order OEM parts from your local BMW dealer or some of the below suppliers.
Bavarian Autosport offers lots of OEM and great high end aftermarket parts. Pelican Parts is a good general supplier of reasonably priced OEM parts for your BMW and other imports. Arizona Autohaus is also worthwhile checking. Braman BMW Parts is another option.
There are a few BMW dealers that offer mail order parts at a discount: Tischer BMW is well known for its great service and OEM Bimmer Parts (a bimmerfest sponsor). Local dealers also may provide parts at a discount for BMWCCA members.
Check out The Frugal Mechanic to see who has the lowest price on replacement auto parts.
OTHER See also (M3, Bentley Service Manual, Other Useful Info)
Locked Key in Cabin or Trunk/Dead key and broken door lock combo
See this thread for opening your trunk without a key. Going through the ski-pass in the middle is also a relatively clean way. If your pass-thru isn't openable, you can drill a hole and try to work a coat hangar hook through there to grab the glow in the dark emergency release handle inside the trunk.
If you have a dead keyfob in connection with a broken lock cylinder, the best method is to try to revive your dead keyfob with a temporary fresh battery (see electrical section of wiki for full battery replacement DIY). A simple 3v calculator battery can be wired to your open keyfob in a pinch for a very temporary work around until you can replace the rechargeable battery.
If you can't get in using a key, the top corner of the driver's door or passenger's door may be gently pried open a little and then propped open to allow a coat hangar (or simliar) to be slid in to grab one of the interior door handles for the double-pull. Wrap the prying tools and coat hangar in protective tape so finishes do not get scratched. Pushing the unlock button will not work as the computer has built in security routines to prevent such a "break-in" attempt. If the car has been locked with a keyfob remote, the double-pulls will be disabled, but they can be re-enabled by pressing the central lock button by the parking brake handle. Due to the design of the locking mechanism in the doors, a traditional "slim jim" approach will not work.
Key cylinder repair DIY can be found in Exterior/Troubleshooting above