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About this Wiki

The E39 Wiki should be used as a tool to help all E39 owners. The greatest feature of the Wiki is that anyone with an account on Bimmerfest has the ability to edit it. If you see something incorrect or notice something missing, simply click on the edit link to the right of any section. Please respect the contributions made by other members.

The E46 wiki has a lot of information, and the I6 engines are largely shared with the E39. If the answer to your question is not here, have a look over there. Also, check out the E39 "Best Links" thread and wiki.

Many thanks to Bluebee, whose tireless efforts cataloguing E39 information created the foundations for this wiki.

Model Summary

The E39 was produced from 1995 to 2004. It was the successor of the E34, and was replaced by the E60. Sales to Germany and the United Kingdom began in 1995, and by 1996 sales to the rest of the world had commenced. The design draws heavily from the E38 7-Series in body construction, v8 engines and electronic technology. Also, many elements (including the 6 cylinder engines) are shared with the E46 3-series.

In the US, the E39 was launched with the 528i and 540i models. The 528i uses the 2.8 litre M52 inline six cylinder engine from the E36 328i, and the 540i uses with the 4.4 litre M62 V8, shared with the E38 740i. In addition to these models, Europe and some other markets received the 520i (2.0L M52), 523i (2.5L M52) and 535i (3.5L M62) petrol models. The diesel models also initially offered these other markets were the 525td (2.5L M51 turbodiesel inline six) and 525tds (525td engine with intercooler). "Individual" cars have interior and exterior colours that are not available in the standard model range.

The M5 variant was introduced in 1998, using the 4.9 litre S62 V8 engine. The M5 is only available as a sedan.

The V8 models were upgraded in September 1998 to the M62TU engine, which features single vanos and electronic throttle. Similarly, the six-cylinder petrol engines were upgraded to the M52TU engine in September 1998. Also in September 1998, the touring body style was released and stability control was upgraded from ASC to DSC.

The major update ("LCI") appeared in September 2000 for the 2001 model year. The major changes are:

  • 525i (M54) replaced 523i (M52TU)
  • 530i (M54) replaced 528i (M52TU)
  • 520d was introduced, using the M47 four-cylinder turbodiesel.
  • 525d (M57) replaced 525td (M51)
  • 525tds (M51) was discontinued
  • 530d (M57) had a slight increase in power
  • V8 engines were unchanged
  • All models received "angel eye" headlights, LED tail-lights, widescreen navigation and various detail changes.

In 2003, the limited edition 540i M-sport model was produced.

Model Range

Petrol Engines

Model Engine Displacement (cc) Bore/Stroke (mm) Comp. ratio Power (kW/bhp) Torque (Nm/ft-lb) 0-62mph (manual) Years Where sold
520i M52 1991 80/66 11.0 110/150 @6250RPM 190/140 @4200RPM 10.2sec 1996-1998 Non-US
M52TU 190/140 @3500RPM 1998-2000
M54 2171 80/72 10.7 125/168 @6100RPM 210/150 @3500RPM 9.1sec 2000-2003
523i M52 2496 84/75 10.5 125/168 @5500RPM 245/181 @3950RPM 8.5sec 1995-1998 Non-US
M52TU 245/181 @3500RPM 1998-2000
525i M54 2494 84/75 10.5 141/189 @6000RPM 245/181 @3500RPM 8.1sec 2000-2003 Worldwide
528i M52 2793 84/84 10.2 142/190 @5500RPM 280/210 @3950RPM 7.5sec 1995-1998 Worldwide
M52TU 280/210 @3500RPM 1998-2000
530i M54 2979 84/89.6 10.2 170/228 @5900RPM 300/220 @3500RPM 7.1sec 2000-2003 Worldwide
535i M62 3498 84/78.9 10.0 173/235 @5700RPM 320/236 @3300RPM 6.9sec 1996-1998 Non-US
M62TU 180/241 @5800RPM 345/254 @3500RPM 1998-2003
540i M62 4398 92/82.7 10.0 210/282 @5400RPM 440/320 @3900RPM 6.2sec 1996-1998 Worldwide
M62TU 218/282 @5400RPM 440/320 @3600RPM 1996-2003
M5 S62 4941 94/89 11.0 294/394 @6600RPM 500/370 @3800RPM 5.3sec 1998-2003 Worldwide

Diesel engines

Model Engine Displacement (cc) Bore/stroke (mm) Comp. Ratio Power (kW/bhp) Torque (Nm/ft-lb) 0-62mph (manual) Years Where sold
520d M47 1951 88/84 19.0 100/134 @4000 280/210 @1750RPM 10.6sec 2000-2003 Some European countries
525td M51 2497 80/82.8 22.0 114/185 @4800 230/170 @1900RPM 11.9sec 1997-2000 Europe
525tds 105/141 @4000 280/210 @2200RPM 10.4sec
525d M57 17.5 120/161 @4000 350/260 @2000RPM 8.9sec 2000-2003 Some European countries
530d 2926 84/88 18.0 135/181 @4000 390/290 @1750RPM 8.0sec 1998-2000 Europe
142/193 @4000 410/302 @1750RPM 7.8sec 2000-2003

Differences between engines

Early 6-cylinder petrol models use the M52 (non-TU) engine. The M52TU has many differences to the M52, such as Dual Vanos and electronic throttle (with mechanical backup). In 2000, the M52TU was replaced by the M54. The M54 engine is very similar to the M52TU, with only a few changes such as fully electronic throttle, a non-return fuel system and an electronic thermostat.

Early v8 models use the M62 engine. The later M62TU has several differences to the M62, including the addition of Single Vanos, electronic throttle and a water-cooled alternator.

VIN decoders

Enter your Vehicle Identification Number (VIN) at these websites for information on the model, engine, gearbox, production date and options of a particular vehicle:,

Owner's manual

Owner's manuals are available from these websites:, (bottom of the page),

Bootlid badges

The E39 generally follows the traditional BMW model naming convention. The first number represents the platform (5 Series), the second is the engine capacity (litres times 10) and the letter is the engine type.

Engine types are as follows:

  • i - Petrol engine (historically, the letter i means "electronic fuel injection")
  • d / td / tds - Turbodiesel engine

Therefore a 525tds has a 2.5 litre turbodiesel engine, and a 535i has a 3.5 litre petrol engine.

Exceptions to the naming convention are:

  • 520i models after September 2000 have a 2.2 litre engine
  • 523i models use a 2.5 litre engine
  • 540i models use a 4.4 litre engine

Engine- Mechanical

Oil and filter change

Like most cars, the typical method of removing old engine oil is by removing the sump plug ("gravity draining"). Some people like to use an extraction pump (cnn thread) or "vacuum extraction" (cn90 thread, Bluebee thread) instead.

For choosing which oil to use, BMW recommends "LL-01 Approved" (aioros thread) for the E39. There is a wide variety of oils used by owners, and the topic is the subject of much debate (bluebee thread, jnyost thread, brandon002 post).

The oil service indicator (SI) light can be reset without any tools (mr-fix video).

Oil pressure

Low engine oil pressure can cause engine damage. The red "oil can" warning light on the dash indicates that oil pressure is low, therefore running the engine may cause damaged. Rattle at start-up (often assumed to be due to Vanos) can be caused by a faulty oil filter housing or check valve in the oil pump (1, 2).

Oil level and oil consumption

As opposed to the red "oil can" light (see above), the yellow "oil can" warning light merely indicates that the oil level is one quart low (fudman post), which does not present an immediate risk. To accurately measure the oil level, the dipstick should be used (dcolangelo thread). Very low oil can cause ticking sounds (rikshot thread) and risk of major engine damage.

In E39 petrol engines, it is common to need a 0.5 litre top-up of oil between oil changes (brandon002 post), which is possibly due to CCV problems (vavet5308 thread). The BMW dealership information (TIS) states that up to 0.7 litres per 1000 km is normal consumption. Excessive oil consumption is likely due to an oil leak or oil burning, and should be investigated (Energizedmortal post). If the spark plugs are oily, the common causes are CCV, valve guides and piston rings (Wgosma post).

Discussions about oil consumption: morrisroad thread, poolman thread 1, poolman thread 2, Bavauto blog

Discussion about dipstick calibration: fudman thread

Oil level sensor replacement procedure: TKC thread,, Westech thread

Oil leaks

Oil filter housing

The gasket at the bottom of the oil filter housing is a common cause of oil leaks (1).

Freeze plug

The freeze plug (also known as Welch plug) is also a possible cause of oil leaks (1- see second half of past).

Oil pan gasket

The oil pan gasket is a potential source of oil leaks, however in many cases the leak has actually been caused by the oil filter housing gasket (1). The official procedure for the M52/M54 involves dropping the subframe, however it is possible to avoid this by cutting the new gasket into pieces (2) or RTV sealant (3).

Valve cover gasket (VCG)

A common source of oil leaks. Leaks can be caused by poor sealant, cracking and occasionally a warped valve cover (1).

Head gasket

A failed head gasket can cause the coolant, exhaust gasses and/or engine oil to mix. Options to check for head gasket failure (and/or cylinder head damage) are a chemical test (also known as "block tester") for combustion gasses in the coolant, compression testing the cylinders or pressure testing the cooling system (1, 2, 3, 4).

Head gasket replacement procedure: Jackcat559 thread

Crank case ventilation valve (CCV)

A failed CCV (sometimes called "positive crankcase valve" or "oil separator valve") is a common cause of poor running (due to vacuum leaks) or high oil consumption (bluebee thread, RDL thread). . The valve itself can fail (jfive96 thread), the associated hoses can leak and the dipstick tube can become clogged (blueebee thread). Some people have replaced the CCV with an oil catch can (eparayno thread). Replacing the CCV is a large job, and easier to do with the intake manifold removed (BavarianE31 thread).

The tube from the CCV to the dipstick can become clogged (blueebee thread).

There is a special "insulated" CCV to prevent failures in cold weather due to condensation freezing (kjet540 post).

CCV test procedures: Bluebee post, Fix The Bimmer video, rdl post, edjack post

M52 replacement procedure: cn90 thread, jfive96 thread, aioros thread

M54 replacement procedure: Jason5driver thread, fudman thread,

M62 replacement procedure: Cerber thread, vicent page

Timing chain tensioner

A failed timing chain tensioner can cause a rattling noise, initially on startup and then constantly as the problem gets worse. If the timing chain slips due to failure of the tensioner, this could result in extensive engine damage.

If the spring in the tensioner is not working, it can cause extra wear on the timing chain guides (1). The M62TU tensioner was revised in 2003, and it is suggested that the revised tensioner has an improved spring (2).

Timing chain guide rails

As per the tensioner (see above), failing timing chain guide rails can cause a rattling noise and extensive engine damage. Timing guide rail failures are more common on v8 engines, particularly after 150,000 miles (1, 2). The M62TU timing chain system is different to the M62, however both versions have experienced failures (3).

Incorrectly set cam timing (which can occur when re-assembling the engine after replacing the timing guides) can cause misfire codes (4).


M54 removal procedure: Jackcat559 thread

Engine mounts

M62TU replacement procedure: blackBMWs thread


VANOS is a type of variable valve timing, which advances and retards the camshaft. Single-VANOS (exhaust camshaft only) is used on the M52 (non-TU) and M62TU engines. Dual-VANOS (intake and exhaust camshafts) is used on the M52TU, M54 and S62 engines.

The seals used by BMW seem to have a limited lifespan, and once they fail the VANOS does not function correctly. This can cause rough idle, stalling and loss of power (ca2014mp2 post). The VANOS can be tested using DIS (TheHockeytowner thread). Many users recommend upgrading to seals made from Viton, such as those sold by Beisan Systems (bluebee thread).

Rattling sounds can be caused by failed VANOS bearings, and there are kits available to rebuild the VANOS unit using new bearings.

As an alternative to using a kit to replace the seals and/or bearings in a VANOS unit, refurbished VANOS units can be purchased from Dr Vanos (Fudman post). BMW does not provide the VANOS seals separately. It sells rebuilt VANOS units for ~$500. According to Beisan Systems (who sell the aftermarket Viton seals), BMW's rebuilt VANOS units are supplied with the same o-rings and have been found to fail in 20,000 miles.

Discussion of VANOS operation and faults: bluebee thread 1, shalyndavis23 thread, bluebee thread 2, 16valex thread

M52 (non-TU) seal replacement procedure: Beisan Systems

M52 (non-TU) bearing replacement procedure: Beisan Systems

M52TU / M54 seal replacement procedure: Beisan Systems

M52TU / M54 bearing replacement procedure: Beisan Systems

M52TU / M54 VANOS replacement procedure: Pelican Parts (eg installing a new or refurbished VANOS unit)

M62TU seals replacement procedure: Beisan Systems, Nervous thread, Edwin post

Valley Pan gaskets

On the M62 engine, the valley pan gaskets can leak coolant. If the gasket has failed, coolant build-up may be visible in a recess of the valley pan ([1]). However, a Rear Coolant Plate leak has similar symptoms (2).

Replacement procedure:, magnum post, scottmm post,

Valley pan discussion: fulltone74 thread, 16hr_Day thread, dbaze540 thread, 540iman thread

Compression test

Discussion about test results for M54 (champaign777 thread) and M62 (flug540 thread).

Engine- Electrical

OBD fault codes

Scanning the fault codes is recommended as a starting point for many problems. Fault code(s) will be stored when the Check Engine Light (CEL- an orange light on the dashboard) is lit. However, there are also many fault codes which do not cause the CEL to be lit. Scan tools- some of which also can reset service lights- are available from a range of suppliers (1).

Fault codes are a valuable clue to diagnosis, but often should not be taken literally. For example, there are many possible causes of a MAF fault code other than a fault with the MAF itself. Similarly, the "cylinder misfire" code cannot always be taken literally. This code is set by the crank angle sensor detecting fluctuations in engine speed as each cylinder combusts (3). The misfire code is determined from a "smooth running test" (also known as "true running test") value for each cylinder, which some scanning tools are able to read. Problems affecting a single cylinder are easily identified using the misfire code, however if multiple cylinders are affected the misfire codes can be misleading.

The E39 uses OBD version 2 (OBD2). Early E39s have the round port under the bonnet, late E39s have the rectangular plug in the cabin, and some E39s have both plugs. For cars with both plugs, the rectangular plug can only report engine and transmission information, however by jumpering certain wires the rectangular plug can communicate report information from all modules (2).

OBD live data

Some OBD readers can provide realtime readouts of engine conditions, which is similar to the Secret Menu, but more includes more detailed information such as fuel trims and oxygen sensor readings. This information can be helpful when troubleshooting engine problems.

OBD live data reference values: TheAngryBear thread

Fuel trims (LTFT and STFT)

The Long Term Fuel Trim (LTFT) and Short Term Fuel Trim (STFT) indicate whether the engine is increasing or reducing the amount of fuel used, to compensate for something. Reading these trims can provide helpful troubleshooting information.

Interpreting fuel trim results: Tutti57 post,ca2014mp2 post 1, ca2014mp2 post 2,Schrodinger's Box video, Bavauto Blog

Engine failsafe error

An "engine failsafe" error means the engine is running in "limp home" mode, due to failure of a critical component. Possible causes include the throttle body (540_M-sport thread, 540VIspeed thread), a blown fuse (Oscswa thread, peetiewonder post), low voltage due to battery/alternator (cgill22 post, LinGG post). However there are many possible causes, so start to narrow down the problem by checking battery voltages and OBD fault codes (Dnell86 thread).

Spark plugs

The official specification is for spark plugs should be replaced every 100,000 miles (Bluebee post) or when showing signs of wear; however some people prefer to change them more often, eg every 50,000 miles (cn90 post). Using the correct spark plug means the gap size is already correctly set; the gaps are not meant to be adjusted on the spark plugs used by E39s (Ryan M post). Checking the condition of the spark plugs ("reading the plugs") gives useful information about how that cylinder is running (,,

The specified spark plugs are:

  • M52: Bosch F8LDCR
  • M52TU: Bosch FGR7DQP or NGK BKR6EQUP
  • M54: Bosch FGR7DQP or NGK BKR6EQUP
  • M62 until 7/97: Bosch F7LDCR or NGK BKR6EK
  • M62 from 7/97: Bosch F9LDCR
  • M62TU: Bosch FGR7DQP or NGK BKR6EQUP

Discussion about using single prong NGK Iridium plugs: cn90 post,

Replacement procedure: crdiscoverer thread, Bluebee thread, Bimmer Zeit video

NGK spark plug codes: cn90thread, Tdog67 thread

Ignition coils

All E39 petrol engines use an ignition coil located above each spark plug ("coil on plug"). Lifespan of ignition coils vary greatly, but failures become more common at higher mileage (1). This can lead to rough idle, a lack of power(2), poor throttle response (3) and sometimes triggers a misfire fault code for the cylinder.

To troubleshoot a single faulty ignition coil that is producing an error code, start by swapping the coils between cylinders and seeing if the error code changes cylinders. Coils can also be tested using an oscilloscope (4).

A worn "spark plug boot" is sometimes the cause of ignition faults (5). A replacement spark plug boot is much cheaper than the whole ignition coil assembly.

Discussion about quality of various brands: NY_98_528i thread

Camshaft Position Sensor (CPS)

A faulty CPS can cause a lack of power, stalling and hard starting (Poolman thread). Failures of the CPS is common problem (Edjack post). Often a faulty CPS will not cause a fault code. It is recommended that a genuine BMW/VDO part is used (ca2014mp2 post).

M54 procedure: Bluebee post, Bimmer Zeit video,RichieE46 thread

M62 procedure: jamesdc4 post, magnum post, BMWtips

Crankshaft Position Sensor (CKP)

Failures of crankshaft position sensors seem to be rare, however in one reported case it resulted in stalling, hard starting and the Crankshaft Sensor fault code being triggered (Girtho thread).

M52/M54 location: barneyhyphen thread

M62 replacement procedure: zapperjoe thread

Cruise control actuator

On engines with a mechanical throttle, a broken cruise control actuator can be a cause of cruise control problems.

Repair procedure: MontanaRob thread


A faulty alternator means the battery is not charging properly, therefore it will cause flat batteries. A properly functioning alternator will measure 14.4 volts while idling at full electrical load (1). A common cause of incorrect charging voltage is the alternator regulator (2).

Instead of replacing the alternator, it can often be rebuilt (3, 4, 5). On an air-cool alternator, the air duct should be cleaned of debris such as leaves (6, 7).

E39s were fitted with 90 Amp, 120 Amp or 140 Amp alternator. The type of alternator fitted to a car can be identified from the sticker (8). However, the M62TU uses a water-cooled alternator (9), and often auto-electricians are not willing to rebuild it. However it is possibly to DIY rebuild this alternator (10).


A failing battery can cause many strange problems with the car, therefore it is often worth checking the battery voltage as a first step. Before disconnecting the battery, some people prefer to wait until the car has gone into "Sleep Mode" (1), however some people consider this unnecessary. A normal cranking speed does not necessarily indicate that the battery is fine (2).

To prevent the build-up of gasses in the truck, the vent tube should be used (3).

Battery drain

A common cause of flat batteries is current drain, however first test the battery to ensure that it is not simply that the battery is too old. Common causes of current drain are a faulty FSU (bluescholars thread), the car is not going into sleep mode (check if light indicating gear on shift lever is out after 20 min without opening doors), the CD changer constantly cycling disks after the car is turned off, or the navigation system.

Procedure for measuring current drain: delfletcher thread, StreetDragster thread

Fuses and relays

Function of each fuse and relay: bluebee thread 1, bluebee thread 2

Failure of the fuel filler door locking solonoid can cause the fuse for the rear door locks to blow (kiwijochen thread).

Earth/ground straps

Poor connections on these straps, including the one located under the cabin air filter (djt5150 thread), can cause various electrical problems.

Ground locations: JimLev post

Cooling system

Warning: the temperature gauge on the dash is heavily buffered and may not show that the engine is overheating until it is too late (1, 2t, 3, 4). Therefore, as soon as the needle moves beyond halfway, turn off the engine to minimise damage.

The coolant temperature can be checked in realtime using the OBC "secret menu" (5). A coolant level sensor is only present on cars with the High OBC (6). The manual method of checking coolant level is using the float in the expansion tank.

When draining or flushing the coolant, it is suggested to disconnect the lower radiator hose instead of using the drain plugs (7).

System overhaul

Many components of the cooling system have a finite lifespan (1 2, 3). Failure of these components can lead to major engine damage through overheating.


A cooling system which is not properly bled can suffer sporadic rises in temperature or loss of cabin heat. The BMW TIS has some specific notes about bleeding the cooling system (NNY528i thread). Some people prefer to replace the plastic bleed screws with brass screws (Mack thread).

Bleeding procedure: cn90 thread, edjack post, jamesdc4 post,

M54 drain plug location: bluebee thread

The recommended coolant is sold by BMW dealerships, however some owners prefer to use other coolants (agouraM5 thread, official BMW information)

Fan shroud

Removal of the fan shroud (and fan) is often required to work on components at the front of the engine.

Removal procedure:, bluebee post

Fan / fan clutch

A failed fan clutch or fan can lead to the fan blades disintegrating at high speed, causing significant damage to parts and panels nearby (1, 2, 3).

BMW recommends special tools for the fan removal, however other methods are possible (4, 5). A trick for tightening the fan clutch nut is to use a piece of string (6).


The thermostat regulates the coolant temperature by routing coolant through the radiator when required. A failed thermostat can cause an engine to run cold(1), or (much worse) overheat.

The E39 uses an electronic thermostat, which causes the engine to run hotter or colder based on engine load. A supplier of non-electronic E39 thermostats claims that the electronic map-controlled can cause cooling system failures (2).

Radiator and expansion tank

The plastic parts within the radiator and expansion tank are common causes of leaks as the parts age (bluebee thread). Some people use an all-aluminium radiator instead of the OEM part.

When removing radiator hoses, the plastic clips are fragile and should be leveraged apart using minimal force (bluebee post).

Replacement procedure: Ohmess thread,

Coolant level sensor discussion: bluebee thread

Expansion tank replacement procedure:, bluebee thread

Outlet temperature sensor replacement procedure:

Radiator cap and system pressure

Some people believe that the high pressure of the BMW cooling system contributes to failures, and therefore install a lower pressure radiator cap (540IA_750IL thread). The lower pressure cap does not affect normal operation, since the system spressure is below 1.4 bar anyway at normal operating temperatures (Gary@GAS post, JimLev post). The difference is that, if the engine overheats, the system vents pressure earlier.

A few people have used a waterless cooling system (chiefwej thread).

Temperature gauge on dash

The temperature gauge is not linear and the 12 o'clock position seems to cover a large range of temperatures (windsmith post, sixpot_simon thread). There are reports of a warning bell sound when the engine is overheating (540iman thread).

The temperature gauge can be recoded to show a more linear reading, to give more warning of overheating (Mr.Philadelphia thread).

Water pump

Discussion of replacement options: bluebee thread

Replacement procedure:

Auxiliary fan

This electric fan operates on low speed when the air-conditioning is used. It also operates at medium and high speed as required to assist in cooling the engine. Failure of the fan itself or fuse #75 (cnn post) are common causes for the fan to not operate correctly. For 1997-1998 models (cn90 post), a replacement fan motor is available (PENER thread 1).

Diagnosis of aux fan problems: shroud thread, Callum1234 thread, coolchu thread

Fan replacement procedure: sleekBMW thread, PENER thread 2

Drive belts

The drive belts (also called serpentine belts) provide power to ancillaries such as power the water pump, alternator, air-conditioning compressor and power steering pump. The belts can crack as they age, eventually leading to failure (which can cause the engine to overhead since the water pump stops working). Special tools to hold the rotating parts in place can be either purchased, created or improvised (bluebee thread).

M54 replacement procedure: bluebee post

M62 replacement procedure: ArbysNight thread

Discussion about diagnosing belt squeal: bmw4te thread

Fuel and intake

Vacuum leaks

Vacuum leaks are one of the most common cause of engine problems (ca2014mp2 post). Symptoms vary, however they can include poor idle, a P0171 error code, lack of power and other symptoms. Sources of vacuum leaks include the intake elbow, CCV, DISA and their associated hoses (poolman thread,Bluebee thread 1, 2, 3).

Common methods of troubleshooting vacuum leaks are:

  1. Reading the fuel trims (see fuel trims section)
  2. Spraying carburettor cleaner around the intake hoses while listening for a change in idle speed (Gmak2012 post, Helmet75 post, ca2014mp2 post)
  3. The "oil cap bag test" (Bluebee post).
  4. Measuring inlet vacuum, using the port at the rear of the intake. For the M54 engine, a reading of 18+ inches of water (with the airconditioning off) indicates healthy intake vacuum (F1Jim64 post).
  5. A smoke test (ca2014mp2 post, Johnstern post). Some people claim this is the definitive test for vacuum leaks, however it requires a smoke machine. Check for leaks at the brake booster, secondary air system and exhaust (ca2014mp2 thread).

Intake elbow

Also called "intake boot".

M54 replacement procedure: bimmerfiver thread, Bimmer Zeit video

Idle control valve (ICV)

A faulty ICV can cause poor idle and stalling. The valve can become clogged with carbon deposits or can have electrical problems. Note that the resistance specification published in the Bentley manual for six-cylinder engines is incorrect (1, 2)

There are many possible causes for a rough idle. For rough idle during a cold start, possible causes included insufficient fuel delivery, vacuum leaks or leaking Vanos seals (3). If there are no fault codes, the problem can occasionally be due to a damaged rotating component- such as the cooling fan or flywheel- that is upsetting the engine's rotational balance (4).

DISA valve

This valve allows different length intake runners to be used, increasing torque at low revs. The main risk with the DISA is that worn parts can become loose (teklord69 thread 1) and get ingested into the engine, causing catastrophic damage to occur (ForcedFirebird post). An aftermarket DISA valve which is redesigned to remove the possibility of a worn pin being ingested into the engine, is available (Gary@GAS thread).

Other possible DISA problems failure can be caused by the valve becoming clogged, the plastic cracking, a failed O-ring (brickwhite thread) or the diaphragm rupturing (uncmozo thread, dakarm thread). A failed DISA valve can cause a rattling sound (Bimmer Zeit video).

Replacement procedure: SolidJake thread, teklord69 post 2, Shires thread

Failed DISA autopsy: teklord69 thread 3

Discussion about diagnosing DISA failure: bluebee thread

Intake manifold

Fuel filter

A clogged fuel filter can cause trouble starting, loss of power and stalling (the same symptoms as a faulty fuel pump).

For 6-cylinder cars, the M54 fuel filter is different to the M52 filter, due to the addition of a pressure regulator (cn90post).

Autopsy of used fuel filters: Nervous thread

M52 replacement procedure: Jamaican71 thread, cn90 thread

M54 replacement procedure: morrisroad thread, casacujo thread, econobox post

Discussion about fuel filters: dalekressin thread

Fuel pump & fuel pressure regulator

A lack of fuel pressure can cause trouble starting, loss of power and stalling (redbull713 thread, agarch92 thread, cwp01 thread). A faulty fuel pump is a common cause, however, lack of fuel pressure can also be caused by a faulty Fuel Pressure Regulator (FPR) or fuel filter.

Fuel pump replacement procedure: GOKOOLJAPAN thread, jamz thread, vetaldj thread, Pistonbroke thread

Relay location: bluebee thread

Valve for testing fuel pressure: luvdriven540i thread, redbull713 thread

Discussion about low fuel pressure and error code 1250: JEREMYZ thread

Fuel level sensor

A faulty fuel level reading is commonly due to a failed fuel level sensor (also called "fuel gauge sending unit"). After replacing the sensor, it is necessary to run Test 21 to reset the dash gauge (QSilver7 post).

Replacement procedure: jamz thread, phid_bombadier thread, lsfeder thread

Fuel tank vent hose

The smell of fuel in the car can be caused by a fault with the fuel tank vent hose (Chillebeam thread).

Mass Airflow Sensor (MAF)

A faulty MAF can cause rough idle and poor fuel consumption. Note that a MAF error code can also be caused by a problem elsewhere in the engine (eg CCV, intake leak). Over time, the sensor can become dirty and requires cleaning.

Typically, a faulty MAF will cause the engine to run rich. However, poor performance due to running very lean has also been observed as a result of a faulty MAF (F1Jim64 post). In this case, no MAF error code was present.

A test for MAF accuracy is the fuel consumption readout (which can be accessed using the Secret Menu). Note that the test should be conducted with the aircon off (F1Jim64 post 1), auaq thread, F1Jim64 post 2).

Removal and cleaning procedure: Bluebee thread, seemyad thread, jamesdc4 thread, sdmike thread

Fuel leaks

Leaking injector seals can cause leanness or fuel leaks (1).

For 530i cars in cold climates, old injectors can distort and cause fuel leaks (2).

Fuel injectors

After de-pressurising the fuel rail (such as removing fuel injectors) the engine might need cranking for a while until the fuel returns to the rail and the engine starts (1).

Gas cap

A loose gas cap can cause a Check Engine Light (IH8DMV thread).

Throttle position sensor (TPS)

Discussion about faults: mylo thread, JimLev post


Oxygen sensors (O2 sensors)

A faulty oxygen sensor can cause poor fuel economy. The sensor can be tested by reading the OBD2 "live data" (ca2014mp2 post) or using a multimeter (Edwin thread). Failure of the heater in the oxygen sensor can cause a fault code (acoste post).

Tools required for M54 oxygen sensor replacement: Bluebee thread

Procedure for M62 oxygen sensor replacement: BMWtips

Secondary Air System

Problems with the Secondary Air Pump (SAP) can cause fault codes or thumping sounds (16valex thread). The failure can be the pump itself (cn90 thread), the valve (cn 90 thread) or the vacuum hoses connected to it (fudman thread). The pump and valve can be rebuilt (cnn thread).

It is suggested that cleaning the Secondary Air Valve can prevent SAP failures (Qubert thread, JimLev thread - see pics in post #17).

Secondary Air System troubleshooting and repair: vtxpower thread

Heat shield

Repair procedure for rattling heatshield: cn90 post

Catalytic converter

If a catalytic converter ("cat") has failed, it will increase exhaust emissions. A clogged cat increase exhaust back-pressure, causing loss of power and perhaps other symptoms. Sometimes a faulty O2 sensor is incorrectly diagnosed as a faulty cat (Schnell5 post).

A clogged cat can be checked using a pressure gauge (poolman post) or analysing the signal output from the oxygen sensors (ca2014mp2 post).

Discussion about replacement cats: mtnAVman thread

Japanese E39s have a warning message "SLOW! CAT. OVERHEAT" for when the catalytic convertor is overheating due to a rich mixture (edjack post).


Transmission applications

Automatic transmissions (taligentx pdf, MatWiz thread)

  • GM A4S-270R: 4-speed, used with M52 engine
  • GM A5S-360R: 5-speed, used with M52 engine
  • GM A5S-390R: 5-speed, used with M54 engine
  • ZF 5HP19: 5-speed, used with M54 engine (gtxragtop thread)
  • ZF 5HP24: 5-speed, used with M62 engine
  • ZF 5HP30: 5-speed, used with M62 engine

Manual transmissions (Qsilver7 post)

  • ZF 5SD-320Z: 5-speed, used with M52 and M54 engine
  • Getrag 5SD-250G: 5-speed, used with M54 engine (USA 525i)
  • ZF/Getrag S6S 420G: 6-speed, used with M62 engine

Transmission fluid replacement

Despite BMW's claim that the transmission oil is a "lifetime" fluid, it has been found that the oil becomes contaminated over time, and therefore requires replacement. The type of oil needed is indicated by the colour of the label on the transmission sump (MatWiz thread, Bluebee thread, hungdynasty post).

For the ZF 5HP19, several brands offer fluids conforming to the Esso ATF LT 71141 specifications (fudman thread).

Discussion about flushing very old auto transmission fluid: toothless02 thread

GM A4S-270R fluid flush procedure: jvcajita thread

GM A5S-390R fluid flush procedure: Jason5 thread

ZF 5HP19 fluid flush procedure: TorqueWrench thread, riro424 thread

ZF 5HP24 fluid flush procedure: vicent page

Manual transmission fluid flush procedure: CNN thread

Trans Failsafe Prog

This warning light indicates that the automatic transmission has gone into "limp home" mode, which uses only 3rd gear. Possible causes include: low battery voltage (1, 2, 3), a faulty electrical connection (4) or electrical problems unrelated to the transmission (5). Mechanical failure of the gearbox occurs is less likely, but also a possibility (6, 7).

Torque converter slip

An internal seal within the torque converter can fail, causing a "Excessive torque convertor slip" error code (gtxragtop post).

Clutch replacement

Procedure for M52/M54: aa240sx thread, David_Levine pdf

Tools for M62 clutch replacement: DavidPorter thread

Dual Mass Flywheel (DMF)

The OEM flywheel is a DMF, which is expensive to replace and cannot be resurfaced. Therefore, some people prefer to replace it with an aftermarket single-mass flywheel (1, 2), however there are reports of the replacement flywheel or solid clutch causing causing gearbox chatter in neutral (3, 4, 5).

Clutch Delay Valve (CDV)

Most manual transmission cars (except M5) include a CDV to prevent clutch abuse. However, many people find it hard to drive smoothly with the CDV installed. To disable the CDV, it can either be modified (Zeckhausen) or removed (CN90 thread, BMWtips).

Differential oil

Discussion about diff oil types and brands: Bluebee thread

Diff oil change procedure: cn90 post, riro424 thread, Jackcat559 thread, BMWtips

Transmission mounts

M57 replacement procedure: philthompson thread

M62 replacement procedure: BlackBMWs thread


Failure of the guibo (also known as flex disk), Centre Support Bearing (CSB) or rear CV joint can cause vibrations or thumping sounds that vary with road speed (1, 2).

For a failed Universal Joint, most people replace the driveshaft, however a DIY replacement of the uni joint is also possible (3).

When disconnecting the driveshaft, beware that the rear of the gearbox can drop (4). Therefore, the gearbox needs to be supported beforehand.

Transmission cooler

Discussion about oil leaks: dannisieze39 thread

Transmission conversion (auto to manual)

Swapping an E39 from auto to manual is more complicated than older or simpler cars, due to the electronic configuration (coding) work required. However, several people have successfully converted an E39 from automatic to manual (zer0vette thread, Chigga thread,geargrinder thread).

Suspension and Steering

Front struts

In the front struts, the shock absorber (also known as "damper") forms part of the suspension geometry, unlike the rear suspension. Poor braking and shudder during braking can be caused by failed front shock absorbers (1, 2).

Rear shock absorbers

Worn out rear shock absorbers can cause noises over bumps, poor ride and poor handling.

Air springs (Touring only)

Touring models with Self Levelling Suspension use air springs in the rear suspension (front suspension is the same as sedans). Cracked rubber can cause the air springs to leak.

There are various aftermarket rear suspension kits for touring models, which either retain the air springs or replace them with coil springs ([2])

Replacement procedure: MLue1 thread, mpribanic thread

Rear ball joints

Worn out rear swing-arm ball joints can cause vibration, squeaking, poor handling and uneven tire wear. Ball joints on M52/M54 cars can be removed with commonly available tools ([3]), however M62 cars require a special tool to be purchased ([4], [5]) or custom made ([6]).

Replacement procedure: Besian Systems, ArbysNight thread

Steering link and tie-rods

Steering rack / steering box

The six-cylinder cars use a rack-and-pinion system (aka "steering rack"), while the V8 cars use a recirculating ball system (aka "steering box").

M52/M54 replacement procedure: iDrift thread

M52/M54 rebuild discussion: champaign777 thread

Discussion about causes of heavy steering: boostmaster thread

Thrust arm bushings

A failed thrust arm bushing is a common cause of vibration at 50-60 mph ([7]).

M52/M54 replacement procedure: easyover thread, cn90 thread, champaign thread

M62 replacement procedure: hotswimmer thread

Other possible causes of vibration: ztom thread, Rami2001 thread

Front Wheel Bearings

Growling/humming noises from the front wheels are often caused by worn out front wheel bearings.

Front wheel bearing replacement procedure: CN90 thread, Zeckhausen, thesteve thread

Video DIY replacement procedure: BIMMERZEIT

Power steering fluid leaks

Power steering fluid leaking from the reservoir or hose can drip into the alternator, possibly causing damage ([8]).

Common sources of leaks are the hose, hose clamp, reservoir cap o-ring and vent hole in the reservoir cap ([9], [10]). Some people fill the reservoir cap vent hole with a Q-tip to prevent fluid leaking through the hole ([11]). Often a leak at the top of the hose can be fixed by cutting off a small length of hose at the top and replacing the clamp with a hose clamp ([12]).

Hose replacement procedure:, jrpastore thread, edwin thread

Power steering fluid flush

If the power steering fluid is cloudy, it should be replaced with new fluid. There is also a filter in the reservoir which eventually requires cleaning or replacement ([13], [14]).

The fluid BMW specifies for the power steering is Dexron III ATF. However, this is no longer available, so Dexron IV is used (bluebee thread, bimmerfest pdf).

Fluid flush procedure: riro424 thread, kknotsail thread, edjack post, starless thread, paulcalif post (for E38)

Power steering pump brackets

M62 owners have reported power steering pump mounts spontaneously failing ([15]).

Failure of the power steering pump mount can disable the water pump, so the engine should be shut off quickly, before it overheats.

Rear sway bar

The sway bar (called "stabilizer" in the BMW schematics) reduces body roll in cornering.

M52/M54 replacement procedure: Jackcat559 thread

Wheel alignment

Wheel alignment affects handling and tyre wear. The BMW alignment specification requires weights to be added to the car during alignment measurements, but some people believe the correct alignment can be obtained without the weights ([16]).

Discussion about wheel alignment: bluebee thread 1, HeyYo thread, bluebee thread 2

Rear wheel alignment procedure: cn90 thread

Free play in rear suspension

Discussion about worn wheel bearings, bushings, ball joints and tie rods: rdl thread


Brake pad and rotor replacement

Brake pads are a maintenance item and should be replaced before the metallic backing starts scraping on the rotor. If the rotor is uneven, it should be machined to restore the flat and straight surface. However, if the rotor is too thin, it needs to be replaced instead (1). It is recommended that "bedding in" be performed for new brake pads (2).

Replacement procedure: Bluebee thread, Ronin009 thread, PJB post, BMWtips

Discussion about causes of brake shudder: stigst3r thread


To replace the brake fluid without adding air bubbles to the system, the process is called "bleeding" the brakes. The methods for bleeding the brakes: getting a second person to pump the brake pedal, or "pressure bleeding" with a compressor connected to the brake fluid reservoir. Another option is using a suction pump at the caliper, however there are mixed opinions about this method.(1)

Regarding the choice of brake fluid, BMW recommends "low viscosity" DOT4 (2).If the ABS pump has air bubbles, specialist software is required to bleed the system (3).

ABS failure / trifecta

Early E39 models use Active Stability Control (ASC), while later models use a more advanced version- Dynamic Stability Control (DSC).

If the DSC, ABS and brake warning lights on the dash are all on, it is known as the "trifecta". This commonly caused by failure of the ABS module or a wheel speed sensor. A "brake pressure sensor" error is often present with the trifecta, however it is rare that the fault is caused by the brake pressure sensor (1).

The speedometer takes its input from the left-rear wheel speed sensor (2), which may help determine the fault. If ABS error code 88 is present (which may cause only the DSC warning light), this is often due to the ABS module or ABS pump (3,4).

ABS module

In some cases, the ABS module can be repaired (1, 2, 3), however the repair is not always successful- even by professionals (4). If the ABS module is replaced, the steering angle sensor needs to be recalibrated (5).

Wheel speed sensors

It is reported that a scratch on a wheel bearing can cause the ABS to continuously activate at low speed (1).

Wheel speed sensor test procedure: bluebee post, Quick99Si thread, 540iman post

Brake pressure sensor

Steering angle sensor

Replacing the steering angle sensor or the ABS unit may require steering sensor calibration. This can be done using Tool32 (1) or INPA (2). It is also suggested that the calibration can be done without any tools (3).

Replacement procedure: rdc8118 thread

Parking brake (handbrake)

Overhaul procedure: cnn thread


Secret/hidden OBC menu

Once you have identified whether you have the High OBC or Low OBC (1), you can unlock the "secret menu" to obtain information about the vehicle. This menu also allows you to calibrate the fuel consumption readout (2).

Low OBC procedure: jamesdc4 post, E39_source video

High OBC procedure: Qsilver7 post, jamesdc4 thread

Dashboard/MID pixels

Missing pixels on the dash and MID display is often caused by problems with the ribbon cable. Replacement ribbon cables are available and there are DIY instructions (1), however the job is very difficult and there are no reports of successful DIY repairs (2, 3). Therefore, most people have had their MID professionally repaired, or purchased a replacement.

If attempting the repair, the black and white connectors on the ribbon cable are slightly different designs. However, with minor modifications, either colour can be used (3).

MID removal procedure:, cn90 thread

MID test mode procedure: RDL post

Wiring diagrams

Volume Two of the Bentley manual contains wiring diagrams.

Trunk wiring harness

Chafing of the wiring harness in the trunk is a common cause of problems with rear lights and can cause other mysterious electrical problems (1).

Module locations

Electrical faults can be caused by problems with the LCM (lighting control module), IKM (instrument cluster module) or GM (general module).

Lighting Control Module (LCM)

Failure of the LCM can cause a variety of lighting problems. The chip inside the LCM can be replaced (1). Later models have the LCM III version, which is harder to repair (2).

Replacement procedure: mario788 thread

Headlights / rear lights

The dashboard warning lights will come on if the resistance of a light circuit (including the bulb) is not within specification. Some brake light problems have been caused by bulb sockets burning out (1) or bent contacts in the socket- even if the lights are still working (2).

Cloudy headlights are a common issue; often the plastic can be restored by polishing (3).

Turn signals

Faults with the stereo (especially aftermarket stereos) can cause the turn signals to stop working (1).

Side mirrors

  • Discussion about faults with auto-dip feature: Prost thread

Ignition switch and lock cylinder

Failure of the ignition switch can cause all kinds of symptoms (1, 2, 3). A test for a faulty switch is the passenger sunvisor light (4, 5).

Ignition switch replacement procedure: DavidC post, synenergy52 thread

Ignition switch rebuild procedure: cal45fan thread

Lock cylinder replacement procedure: SNARF thread

Licence plate light bulb

Replacement procedure: bluebee post


The keys perform 3 functions: immobiliser (EWS), keyless entry (FZV) and alarm (DWA) (1). Cars were originally supplied with four keys: two "master" keys, one "valet" (does not unlock trunk or glovebox) and one small plastic "wallet" for emergency use only (2). Early models use a square shaped master key, later models use a diamond shaped master key. All keys include the EWS transponder required to start the engine.

Replacement master keys from a dealership can be expensive, however aftermarket replacements are also available at lower cost (3, 4, 5, 6). When an aftermarket key is purchased, the EWS module car needs to be reprogrammed (this module can be removed from the car to send to the key supplier). Another cheap solution is to purchase a valet key from the dealership and transplant the EWS transponder into an aftermarket master key (7).

Discussion of options when keys are locked in car: vetaldj thread

Keyless entry (remote central locking)

To unlock a car when the keyless entry is not working, the doors and trunk can be manually unlocked with a key (1). If the car's flat battery prevents the central locking from working, an external battery can be used to power the system (2).

"Initialization" for the keyless entry is required for new keys or when the key battery is replaced (3, 4, 5). Lost or stolen keys can be deactivated so that the keyless entry no longer works for them (6).

Charging key batteries: traviss351 thread

Replacing battery in diamond key: BMW_525i-Noob thread

Replacing battery in square key: alfonso12 thread, Billy_Hopkins thread

Replacing rubber buttons in square key: QSilver7 thread

Alarm and EWS (immobiliser)

The alarm is part of the EWS system. Causes of false alarm activation include low battery voltage (1), a hood switch (also known as "hood sensor") that is faulty or is no longer positioned correctly (2), faulty siren (3) or faulty motion sensor (4). Faults with the hood sensor can result in the alarm not arming (5).

The EWS has 10 "slots" where keys can be programmed, however it is suggested that a new key can be programmed to replace an old key (6).

Siren replacement procedure: BMWtips

EWS overview: bimmerfest pdf

Discussion about EWS options for replacement keys: RocketSurgeon thread 1, RocketSurgeon thread 2

Rain sensor

Replacement procedure: eaglecomm post, Wade_Dwyer thread

Retrofit procedure: davidf procedure

Coding software

With the right software and cable, users can adjust electronic settings such as autolocking of doors (1, 2) and rain-sensing wipers (3). Coding procedures for the E39 mostly the same as the E46.

Carsoft, PA Soft (1), INPA and DIS are commonly used for coding. The following forum contains a lot of information on coding:


Door locks

Door lock actuators are a common failure, causing a single door to be unable to lock or unlock.

A door that is stuck locked is a difficult situation, because the door card cannot be removed while the door is locked. Instead of destroying the door card, a small hole can be made in the door card to access the torx bolt (1).

Actuator replacement procedure: fudman thread, 540iman thread

External door handle

Replacement procedure: TIPenta thread

Trunk lock

A failed trunk lock actuator prevents the trunk (also known as "boot") from closing (1). If the button on the trunk to open it is not working, this can be caused by frayed wires in the rubber boot (2).

  • Replacement procedure for actuator: BMWtips

Trunk strut (sedan only)

Tailgate (Touring only)

Water in rear footwell

The common cause of water in the rear footwell is the door vapour barrier (1). Another possible cause is a blocked door drain (2).

Vapour barrier repair procedure: speedchase thread, bimmerfiver thread, stilljester photos

Water in trunk

Discussion about clogged drains: HeavyJ thread

Hood adjustment

Discussion about hood adjustment: JCGinMA thread

Hood release (bonnet release) cable

How to open the hood when the cable is broken: 528inOttawa thread

Cable replacement procedure: cn90 thread, Edwin post, larina thread

Splash shield / front undertray

To access the underside of the engine, the splash shield (also known as undertray or "Engine compartment screening- front") needs to be removed. There are a few different designs of E39 splash shields (such as Phillips head bolts vs M10 hex head bolts, and some splash shields have recessed bolt holes).

The splash shield is in two pieces, and the rear section needs to be removed first (1). To remove the front section, remove all the bolts, then slide it towards the back of the car to free it from the front bumper (2).

Door seals

Upper seal replacement procedure: davegraham page

Door jamb seal discussion: Bluebee thread

Window trim

Replacement procedure:

B-pillar trim

Replacement procedure: porksoda thread

Windshield trim

The rubber trim cracks over time (1).

Replacement procedure: blackBMWs thread

Headlight adjusters

The OEM headlight adjusters are made from PBT, which over time becomes brittle over time and breaks. This results in the headlights pointing downwards or moving around. There are many options to repair/replace them, such as buying plastic or metal adjusters(1), or making your own adjusters (2). Headlights on 2002+ cars require a different technique for disassembly (3).

The headlight levelling sensor is located in the front suspension (4).

Replacement procedure: findog thread, jdjg thread, roderick thread, BMWtips, gmindas video, Gary McKee video, MegaBusterBlaster video

Cloudy headlights

Heat and moisture can lead to a cloudy headlight lens (1). Also, over time the outer surface of the lens can become dulled, which can be fixed by polishing (2) or sanding (3).

The headlights are not sealed, they have drain tubes (4).


Water leaks in the cabin can be caused by problems with the sunroof drains (1, 2, 3).

Problems with the sunroof opening can be caused by dirty/bent guide rails or broken lifting arms (4).

For lubrication of the sunroof guide rails, BMW specifies that an oil should be used (5), such as the oil used on a bicycle chain.

Roundel (BMW trunk and hood badges)

Paint can flake off from the emblem over time. The rear badge is slightly smaller than the front (1).

Replacement procedure: bluebee thread, ILVSMOG thread

Rear bumper bar

Removal procedure:


Warning: when working around airbags or seat occupancy sensors, disconnect the battery first to avoid triggering the airbag light (1).

Cup holders

These are very fragile, therefore they commonly break. When broken they are unable to be closed.

Dashboard trim

Cracks may appear in the woodgrain trim over time, especially on the CD player cover (1).

Internal door handle

Steering wheels

Cars before 03/99 have a single stage airbag. Cars after 03/99 have a dual stage airbag. Therefore a replacement steering wheel must be in the correct date range for the airbag to function.

If the steering wheel lock jams, it can be unlocked by drilling the underside of the steering column (1).

Takata airbag recall

The airbag for the sports steering wheel on 2002-2003 cars is part of the Takata airbag safety recall.

Front armrest

Some drivers have found the American front armrest with plastic cradle to be uncomfortable for their elbow, and have replaced it with the European armrest which does not have the cradle. There are several types of European armrest available (1, 2).

Door cards / interior door panels

Seat belt

Window regulators

Stuck windows are often caused by the regulator failing (1). Alternatives to replacing a faulty regulator are using a repair kit (1) or JB Weld (2).

Phantom window opening

All of the windows are opened when the unlock button on the key is held down (1). Another possibility is a faulty GM5 module (2).

Front seat control module

The control module and wiring can become damaged by the movement of the seat. This causes faults in the seat movement and steering wheel reach adjustment (1, 2, 3)


Seat Twist

On the front seats, the cables which control the movement of the seat often fall out. This causes the seats to twist (1).

Rear seat removal

For sedans, the seat base is removed by pulling it upwards at the front. The seat back is removed with two bolts in the bottom corners, then lifted upwards to release it from the two mounting tabs at the top (1, 2, 3).

For fold down rear seats, the mounting bolts are slightly different (4- see Figure 28).

For integrated child seats, there may be additional clips to remove (Black5 post).

Heated seats

There are reports of fires caused by heated seat malfunctions (1, 2, 3)


There are various products to clean dirty headliner (1). Sagging headliner can be re-glued (2, 3).

Airbag warning light

Failure of the occupancy sensor is a common cause of an airbag warning light. The belt buckle can also cause the warning light (1). Resetting the airbag light requires special equipment (2).


The latch can fail, making the glovebox unable to be opened (1).

Cigarette lighter

A faulty cigarette lighter is often caused by a blown fuse, but a faulty socket can also be the culprit (2, 3).

Instrument cluster

Indicator stalk

Rear parcel shelf

To access some rear suspension components, removal of the parcel shelf is required.

Sources of rattles

Unfortunately, there are many potential sources of rattles in a car's interior. Some documented causes for the E39 are seatbelt spacer/shim (1 and 2), door catch receiver plate (3, 4).

Climate control

Final Stage Unit (FSU)

A common cause of erratic climate control behaviour is the FSU, also known as "blower resistor". It has also been known to drain the battery, by running the fan when the car is switched off (1). The FSU can be tested (2, 3). One mode of FSU failure is ageing resin on the circuit board, which can be repaired (4).

On right-hand drive cars, the FSU is on the drivers side, so the kick panel needs to be removed (5).

Some cars also have a rear FSU (6).

Airconditioning smells

Mould in the airconditioning system is the common cause of "gym sock" smells in the cabin (1). Also, the cabin air filters require frequent replacement (2, 3).

Airconditioning fan

A noisy interior fan (also known as blower fan) may be fixed by cleaning and lubricating it (1, 2).

Erratic fan behaviour is likely due to a failed Final Stage Unit.

Evaporator condensation (water on ground/interior)

Condensation from the aircon condenser can cause water to drip below the car (1). This is not the sign of a fault, however make sure not to confuse leaking coolant for water.

If the evaporator drains are faulty, this water may enter the cabin (2).

Ambient Temperature Sensor

This sensor often damaged by parking curbs, due to its location. When the sensor is open circuit, it reads as -40°F (-40°C); however a faulty sensor can also read high.

Automated Recirculated Air (AUC) mode

When the climate control recirculation mode is set to auto ("A"), the AUC sensor is used to determine whether fresh or recirculated air is used (1).

Centre vent

It is common for this vent to crack in the top-left corner (1).

IHKA button

It is common for the climate control temperature adjustment buttons to crack.

Beep alerts

A single beep is a warning that ice is likely, due to the outdoor temperature. A triple beep is the hourly alarm (1).

Milage tamper dot

A dot in the dash display indicates an error with the mileage calculation (1), therefore the mileage data may have been tampered with.

Airconditioning compressor

A faulty or loose compressor can cause rattling sounds from the engine bay (1).

Heater valve

This valve (also called the heater solonoid) regulates the hot air coming in to the cabin. On cars with dual zone climate control, if one side of the car is stuck on hot or cold, it is likely because this valve is stuck (1). A leaky heater valve can cause coolant loss (2). Occasionally, the valve can also cause a flat battery (3).

Solar sensor

Climate control units on cars manufactured after 09/2000 use a solar sensor. The climate control will work without the solar sensor, however it will cause a fault code (1).


CD changer "no discs"

A "no discs" error is commonly caused by a faulty disc changing mechanism (1, 2, 3). In some cases, the problem can be fixed by dismantling and cleaning the changer (4).

AM radio reception

Aux connection

For cars built after 09/2002 without navigation, the BMW aux cable can be retrofitted (1, 2, 3). For earlier cars, retrofitting of the BMW aux cable also requires stereo to be replaced with one from after 09/2002 without navigation (4).

Other options for listening to audio from mp3 players etc include tape to aux cable adaptors, FM transmitters and aftermarket stereo replacements.

Head unit


Jump starting

BMW recommends jump starting be done using the positive connection on the intake manifold and the earth connection on the strut top (1). Before attempting to start the dead car, it has been suggested to have the cars connected with the donor engine running for 3-5 minutes (2).

Technical Information System (TIS)

The official BMW information provided to dealerships. It contains repair procedures and other technical information.

Raising/jacking the car

The jack pad near each wheel is the preferred location for jack stands (1). However, finding a lifting location is not as straightforward.

For the rear of the car, many people use the differential, although others believe this can damage the differential or bushings (2).

For the front of the car, there is a jacking point on the engine crossmember (3- see second photo), however this location is hard to access on some models (eg requiring a long-reach floor jack) and some people have reported that the jacking point is not fitted to their cars crossmember. An alternative is to lift the car on each side using the chassis rails (4- see Figure 6), which requires removal of the plastic underbody shields on each side of the car.

Instead of using jacks, another method of raising the car is with ramps (5).

Jack pads (wind noise)

Missing jack pads (also known as "support lifting platform") can cause wind noise (1, 2, 3) and difficulties using the BMW jack.

Windshield wipers

A non-standard wiper blade is used, which is often unavailable at local parts stores (1, 2).

Diagnosing windshield wiper problems: 540isaac thread

Windshield washer and headlight washer

The washer system layout depends on whether the car has the "intensive wash" option, which uses a separate reservoir and pump.(1) The Touring models include a washer for the rear window.

Leaks from the reservoirs can be caused by the grommet (2). Problems with the hoses can cause a water leak and reduced effectiveness of the washer jets. Blocked jets can cause reduced effectiveness.

Parking Distance Control (PDC)

Front and rear acoustic parking sensors were available on the E39. The kit was also sold as a retrofit (1).

Wheels and tires

Tire Pressure Monitoring System (RDC / TPMS)

An option on euro-spec E39s (1)

Replacing a broken engine

The E39's large amount of integration between the electronics of the engine and the rest of the car ("body electronics") means that replacing engines is more complicated than on older cars.

Also, the immobiliser system (EWS- described here) requires the several components to be synchronised. Some of these components are unable to be re-programmed or reprogramming requires expensive equipment. The components which need to be synchronised are: DME, EWS control unit and the electronic chip inside the ignition key. The easiest method to maintain synchonisation is to send the new DME, EWS and the car key to a specialist for re-coding (MichaelK5990 thread, 766jack thread). Having the existing key re-coded avoids the need to replace all the locks in the car. Another option is use the DME from your old engine on your new engine.

Even matched EWS components can need re-syncing (HTK12 post).

Replacement with identical engine:

Using a replacement engine of the exact same specification (same family, same capacity, same vanos configuration) enables the old engine's electronics to be used with the new engine (1). This avoids the complications involved with modifying the EWS system.

Alternative sources for replacement engines:

- M52: E36, E38 (pre September 1998 only) or Z3 (pre September 1998) (1)

- M52TU: E46, E38 (post September 1998 only), Z3 (post September 1998)

- M54: E46, Z3 (3.0L only), Z4 (pre September 2006), E53. Note: the E60 and E83 models also used the M54 engine, however they started production after the E39 was discontinued, therefore there may be changes which are incompatible with the E39

- M62: E38 (pre September 1998 only), E31 (4.4L only)

- M62TU: E38 (post September 1998 only), E53 (pre July 2003 only)

Note that coding is required when installing an engine from an automatic car into a manual car, and potentially vice-versa.

Replacement with same engine family, but different engine specification:

This section described engine swaps within the same family (eg M52, M54, M60 or M62). Although the M52 and M54 engines are similar in many ways (similarly, the M60 has many similarities with the M62), unfortunately the small differences may cause difficulties for an engine conversion (1). Therefore, it is often much more straightforward to use a replacement engine from the same family. Nonetheless, there are still challenges when remaining in the same engine family. Therefore, in addition to the issues noted above, the following issues should be considered.

Capacity changes require a change of engine tuning to operate at its full potential. It is possible to get the new tune coded into your old DME (2), thus avoiding EWS modifications. Also, it may be possible to 'virginize' a DME so that a new tune can be used (3). Note that sometimes the ancilleries are different for each engine capacity, for example the maf, intake, airbox are different between the M54B25 and M54B30 (4).

Changing the vanos configuration (eg replacing a single vanos M62 engine with a dual vanos M62TU engine) is considered not a practical option (1, 2, 3), since it would require extensive modification to the cars electronics.

Engine swaps for power increase

"Anything is possible, the question is if it is worth your time and money. I have seen someone swap an engine out of a 2006 M3 into a 1989 M3. Was it really cool and fast? Yes. Was it really worth spending almost $20k for it? No. For that kind of money he could have built up an impressive euro S50 and blown away his current setup" -Jimmys530i

The issues discussed above in replacing a broken engine all apply, plus added complications due to differences in how the car is configured for each engine.

E39 engines- 6 cyl:

E39 engines- V8:

For 6 cylinder owners, it will probably be cheaper to trade in your car and buy a V8 E39 than to do a V8 engine swap on a 6 cylinder car (1, 2, 3, 4, 5).

  • BMW M62TU replacement of M62: Theoretically, this swap is similar to M54 replacement of M52TU (see above).
  • BMW S62: This swap is expected to be very difficult (1, 2)

Non-BMW engines:

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