DIY Mashup -- Redo - Bimmerfest - BMW Forums

Welcome to Bimmerfest -- The #1 Online Community for BMW related information! Please enjoy the discussion forums below and share your experiences with the 200,000 current, new and past BMW owners. The forums are broken out by car model and into other special interest sections such as BMW European Delivery and a special forum to voice your questions to the many BMW dealers on the site to assist our members!

Please follow the links below to help get you started!

Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > 3 Series & 4 Series > E46 (1999 - 2006)

E46 (1999 - 2006)
The fourth generation 3 Series (E46 chassis) was introduced in 1999 and set the standard for engineering and performance during it's years of production including being named to Car & Driver's 10 best list every one of those years! ! -- View the E46 Wiki

Thread Tools Display Modes
Old 11-20-2010, 09:20 PM
jimmelo jimmelo is offline
Officially Welcomed to the 'Fest
Location: Raleigh NC
Join Date: May 2007
Posts: 162
Mein Auto: 2011 335d
DIY Mashup -- Redo

I am redoing my old post due to inability to edit old posts. I'm updating pictures and some of the text, but for the most part the following is simply cut and paste from my old post.

Do you have the following codes? Are you going to clean your MAF sensor? Is your idle really spotty, car will shut off from the idle dropping low? Car enters a weird funky mode where it seems like you get no power and the muffler sounds really weird? Car jerks when you step on the throttle in 1st or 2nd gear? People are telling you to check the air intake duct? You might have an air leak somewhere? Do you also occasionally get the dsc, ABS, brake light to come on but when you turn the car off and then back on it will go away?

Well I did and I was throwing the following codes. Now I don't have any. It only cost me less than $200 and if I had a good mashup DIY I probably could have fixed it all in about 4-5 hours tops, and I am no mechanic. Had never touched a car engine before in my life. I drive a 2002 E46 330Ci convertible. And I found it all on here, but in different parts. Even if you have to buy the tools you are probably only talking about an extra $100 for the tools (excluding the torque wrench which can be expensive).

P0313 random misfire at low fuel
P0300 multiple random misfire at low fuel
P1353 Misfire during start cylinder 6
P1347 Misfire during start cylinder 3
P1351 Misfire during start cylinder 5
P1501 Idle Control Valve
P1083 Fuel Control Mixture lean bank 1 sensor 1
P1085 Fuel Control Mixture Rich Bank 1 Sensor 1
P0455 Evaporative Emissions control warning
P0171 Running lean bank 1
P0174 Running lean bank 2
P0128 Thermostat warning

So don't be scared jump in! Almost all of what I am about to post/re-post can be found in the wiki, yes the wiki, read it, read it again. And if you can't find it there a good google search will find it for you. Why am I doing this? Well because if I had known in advance I would have done all of this in one fell swoop and after seeing lots of posts on the same issues it looks like many others are having the same issues. Hopefully they can gain from having this all in one place.

This worked for me, this may not work for you. My problems may not be your problems. This is not an exact science, especially because we are using Autozone code readers. They are not precise in the least bit. But for less than $200 I figured why not try. And it worked. I am not a mechanic. I am not a professional. Do this at your own risk.

So here is what we will cover in this post:
1. MAF (Mass Airflow sensor) cleaning
2. Air filter replacement
3. Air intake hose replacement
4. Butterfly cleaning (aka DISA valve aka intake manifold resonance valve)
5. Idle control valve cleaning (ICV)
6. Thermostat replacement
7. Belt replacement
I did not do this but again if I had read it earlier I probably would also go ahead and replace the thermostat hoses as a precaution.

1. CRC MAF cleaner (any auto parts store $6)
2. Air filter $17 Part #13-72-1-744-869
3. Air intake hose (connects to the idle control valve, $16) P#13-54-1-438-759
4. CRC ICV cleaner $6
5. New Thermostat $65 P#11-53-7-509-227
6. BMW Coolant $20 P#82-14-1-467-704 (must be from dealer, and you will need some if you replace thermostat, but I recommended doing the coolant flush as well, check the wiki)
7. New Belts $50 for both Serpentine belt P# 11-28-1-437-475 A/C belt P# 11-28-7-512-762
8. Extra rivets 2-3 of the cooling fan rivets (bigger one), and maybe 2-3 for the intake ducting to the radiator rivets $.40 each
9. Replacement connector rubber hose (same as for the fuel filter). P# 11-72-7-545-323 Very small hose that will break as you do all this so better to have some around.
Total $170

Socket wrenches 6mm, 10mm, 13mm
Torx set 25, 30, 40, 50 (just get a set they aren't that expensive, try sears they have great prices on tools)
Breaker bar (not essential but very useful)
Torque wrench (only for the thermostat)

I recommend putting the car on ramps and removing the splash shield under the car, mostly in case you drop something it will fall through. To do so remove the screws holding up the splash shield. In some DIY's they mention removing 3 rivets (Plastic clips) that my car did not have. I just had 7 screws. Whatever your situation, undo the screws (they do not come out all the way) or the rivets and it will fall off. You really only need to turn the screws about a 1/4 turn. Skip ahead if you need help understanding how the rivets work (I know I did the first time I had to remove one). Once you figure out the plastic rivets they are easy to remove.

Ok so now it's time to really get started. Let's start on the air filter side. Let's remove the whole Air Box and Air Ducting. First remove the Air Ducting above the radiator fan. Here is my first rivet (you may have removed one on the splash guard). That red circle is pointing out the one rivet I had to remove. I only had to pull out the one rivet at the top left. From there I was able to slide out the ducting off the other two rivets.

You can see here how the ducting is open ended on the bottom two rivets. From what I understand not all are open ended so make sure you check yours. You may have to remove two more rivets. But no problem, you're a pro now.

The rivets have a plastic "nail" that is driven in the middle to expand the rivet and keep it in place. The key to removing the rivets is to pull the nail in the center. If you screw it up like I did don't sweat it, the rivets are cheap at your dealer. Might want to get a few ahead of time. Here's a picture of the rivet with the plastic nail pulled out.

Anyway from there pulling that piece is easy you just have to uncouple it from the air box.

Now on to the next piece, the air box itself. Again very easy. Get a 10mm socket and loosen the two bolts holding the air box to the engine compartment and the clamp as highlighted here. You can use a flat head screwdriver or a 6mm socket to loosen the clamp on the hose.

You may have all ready done this but go ahead and remove the MAF wiring harness. There is a wire clip holding the wiring harness down to the MAF unit. You just need to gently pull it up with your fingers or use a flat head and the unit should slide off. In the picture above the sensor wires have all ready been disconnected. The wires and the clip are also circled.

Ok the next part is not that hard but it may seem like it. Grab the air box on the MAF sensor side. Pull it straight up and tilt it forward, while also pulling it back towards the steering wheel. I know that sounds like it contradicts itself but it doesn't. I didn't mention the ducting from the box to the engine should have been de-coupled (that's why you loosend that clamp!). Remember this because this is how it goes back in.

Keep all the rivets, clips in a place where you know you won't confuse them or lose them. I took a bunch of bowls out of the kitchen and put rivets and bolts or whatever in different bowls to keep the different sections separated. Please don't tell my fiance.

Put the air box aside for now. You will deal with the MAF and the filter later. Let's keep moving in.

Next step we are going to move towards the ICV and the butterfly flap aka the DISA valve.

You will have to remove the cabin air filter and it's container. Again very easy. I did not replace my cabin air filter but now would be the time to do it. I drive a convertible so what do I care.

Let's get the wires out of the way. The cabin filter box has a long flat clip "box" guide that holds some wires and tubes. No need to disconnect the battery leads or anything. You just have to take them out of the plastic guides. Just squeeze it or use a flat blade and the guide box should snap apart. Here's what you are looking to do:

Just move those cables out of the way by pushing them out of the tray and down onto the engine block. Now onto the micro filter. Undo the retention clips highlighted above. Just twist them with your finger a quarter turn counter-clockwise. You can now just pull out the cover. Lift it a little from the front and pull it out. Same thing for the filter underneath. You will now expose 4 Torx screws. Some say T-40 but mine were T-30. Whatever, you have a set, find the right size. Now pull off the cabin filter tray. As you pull it out you will likely pull off some rubber molding that helps keep things snug and clean in there. Just make sure you keep track of it.

A lot of what this is is mostly making room to work easier. You could try it without all of this but to be honest, why? It takes an extra 20 minutes but gives you a ton more room to work. The next room making task is over at the brake master housing area. Remove the molding on top. Take a good look at it. See where the tubes go through the housing? Notice the rubber grommets holding it in place to the plastic housing. These pop off real easy. There is also one that just covers a hole in the plastic. Keep track of these as you take the molding off. Remove the two retention clips on the plastic housing (just like on the cabin filter tray). One is the far left red circle. The other should be the far right circle but as you will notice mine is missing/broken off. Somehow that plastic piece broke before I even went in there but I circled where it should be so you know.

This piece is a pain in the ass, not because it's hard to do but just because it's more just luck. I can't really tell you how to take it off or put it back on, although the following seemed to work the best. First pull it up and unseat the plastic piece. Now push out and away from the brake cylinder. Now push it down. Take the hosing and push it past the plastic piece (towards the cabin). From there you should be able to pull the plastic piece up and out. It's a pain in the ass to put it back in as well, but just make sure you seat it back on the frame.

I pulled this rubber hose out of whatever the hell it connects to by accident. If you do this, don't kill yourself trying to put it back on. If you look at the tip of the hose there is a round rubber grommet. The rubber grommet pulls off. It took me forever to figure that out. Pull the grommet off and mount it first to the metal. Then you can slide the barb through the grommet and you are good to go again. I spent about an hour trying to just push it back in until I figured that out.

Well now that that piece is gone move on to the next air duct. You will now be removing the air duct after the MAF. Pretty simple but be careful. I recommend loosening the clamps first with a 6mm socket. I had to use the socket because somebody was being funny when they put my car together and the clamp was facing down so I couldn't even see the head, much less use a flat head to loosen it. You will also need to undo the F-shaped barb going into the duct. Gently pull it off. If you squeeze the hole it goes into it will give the barb some room to move as you pull it off. I had more success that way than using a screwdriver.

See the hose I highlighted? That is the one that will crumble apart. What you want to do is once you get that F-shape barb off is to use a very tiny screwdriver to sort of scrape that hose off. The rubber hose is very small and it connects a hard plastic tube to a barb in the F-shape connector. I have no idea what any of that is doing. They use the same type hose on the fuel filter if that helps and it does the same thing there, connects a small hard plastic tube to a small barb on the fuel filter.

Ok you now have that air duct off. Let's take off the DISA valve and the adjustment box. You'll need a T-40 torx to loosen 2 Torx screws holding it on. You will also need to undo some electrics on the top right side. Just look for the wire clip. If I remember correctly in this case you just squeeze the wire clip it will let you pull off the unit.

and with it coming off to give you an idea which two torx screw as there are a few in the area and so you know exactly what piece we are talking about.

Set that aside for cleaning. Now get yourself some room. and remove the torx screw (T-40) to the right of the DISA valve you just removed. In the next picture you will see where I highlighted the screw hole highlighted on the far right in blue. The tubes, etc have all ready been moved to the side. It should be fairly easy to figure out as you are looking for a T-40 torx screw that is holding some wires and tubes in place. Again this is not necessary but man does it really make a difference for the extra 5 minutes that it takes.

Now onto the ICV. To remove it you'll need to remove 2 Torx screws (T-40), one nut (10mm), and the clamp (6mm) on the small hose of the air intake boot going to the ICV. You will also need to remove some electrical connections. Again squeeze the wire clip to release it. The Torx screws, the bolt, and the electrics are highlighted in red in the picture below. I also highlighted in yellow the crack in the small elbow of the lower intake boot so you can see the common issue with this boot.

Just follow that elbow to the small hose clamp. This is part of the lower air intake boot that I strongly recommend you replace now. I've also highlighted in green on this picture where the two previous torx screws from the DISA valve came out of.

Now that everything is disconnected from the ICV it's time to pull it out. It is mounted to a plate and held on to the plate by a rubber "sleeve". Just gently pull on it, you may need to twist to get the metal mounting bracket out so the ICV will pull out. Just keep trying it will go. And here it is out. You can see the plate it is mounted to in the pic.

and the ICV out of the sleeve.

Once you have the ICV out go ahead and undo the clamps on the air intake boot if you are replacing it. Again a 6mm works well here. Again if BMW was being funny and put yours upside down I recommend flipping them around. You are now done taking things apart on this side of the engine.

So let's do some cleaning of the MAF, ICV, and the DISA valve. Pull off the MAF from the Air box you removed earlier. Very straightforward by this point. Now find a nice place to spray, get some goggles on to protect your eyes from spray. This sh*t is caustic! Follow the instructions and go crazy cleaning your MAF. Do the same with the ICV with its appropriate CRC can. With the ICV I also used a lint free rag and tried to get in there as much as possible. You are only spraying the metal parts. Cover the part where the electrics go as the CRC could damage that.

I just wiped the butterfly flap down with a lint free rag and removed as much crud as possible. I didn't use any cleaner and here are the results. It was pretty gunked up before I cleaned it.

While you are waiting for that stuff to dry go ahead and replace the air filter. Just undo the clips on the lid of the air box, pull out the old filter, and pop in the new one. Pretty straightforward and hard to screw up. Sorry no pic as they limit how many pics I can use in a post. But the air filter was the easiest part and I am sure if you have made it this far you can do it without pics.

That's really it for cleaning and spraying now you can put this side of the engine back in order. Put everything back together in reverse order, but stop before you put the air box in or the first piece of air ducting you took off on top of the radiator. That will go in at the very very end. The next step is to pull out the radiator so you can replace the thermostat and the belts. If you were really smart you would go ahead and do the coolant hoses now too. I didn't do it so I don't have pics but the DIY sounds really easy once you are this far.

First you need to remove some electrics and a torx screw T-25 that are highlighted. The electrics are pretty easy to get off, no tools needed. The image is as if you were looking out from the engine so this will be found on the passenger's side.

On the driver's side there is a rivet holding the radiator. Again pull out the middle "nail" and your on your way. You can see I have the nail more than half way out on this rivet.

Now just pull the radiator straight up. It's that easy. As you pull it up look down into the engine you will see where the radiator is cradled by a frame and the radiator has some clips on the bottom that rest on that rail. It will be easy to understand once you pull it out.

Now you are looking at the belts and the thermostat and have some room to work. The big plastic thing is the thermostat and I have circled the two tensioners that keep the belts tight. The one on the left is the A/C belt tensioner and the one on the right is the serpentine belt tensioner. There is a plastic piece covering the torx underneath. Just pry off the plastic with a screwdriver. Don't worry you can't really hurt it and it will pop off.

Now that you have the caps off and have located the Torx bolt get a T-50 and the breaker bar. Do the A/C belt first. All you need to do is put the T-50 on there and turn clockwise. With the breaker bar this is extremely easy. Just go slow. As you turn clockwise you will see how the belt loosens. Don't just let go of the breaker bar when the belt comes off, let it up back easy.

Now go do the same thing with the serpentine belt. Make a drawing before you undo this one. Or take lots of pictures so you know exactly how it goes back on.

Ok, now back to the thermostat. You need to disconnect the electrical thing-a-ma-jig. Just like everything else there's a wire clip that you need to undo. This one needs to be pried off like the MAF sensor and not squeezed.

Now that that's off you will need a 13 mm socket to remove the bolt behind the thing-a-ma-jig (upper right in the picture) and 3 10mm bolts located around the thermostat.

The radiator hoses have some clips that keep the hoses clamped on to the thermostat. Pretty easy to figure out. Just pull them out. Now just pull out the thermostat and you will have to wiggle them out of the hoses. If you are replacing the hoses do so now. You will leak coolant because we are leaving the coolant flush until the next piece, but you might want to do the coolant flush first if you are doing everything in one big push, that way you won't leak too much coolant now.

Clean out where the thermostat goes in to the engine. Use a clean lint free rag. Grab your new thermostat and install it. Make sure you only use 7 ft-lbs of torque (10 N-m) on the bolts to install them.

Now install the belts. Make sure the belts line up with the grooves on the pulleys. As you install the belts go slowly as you let the tensioners take up the slack on the belts. This is where a breaker bar comes in real handy.

From there work your way backwards. When you have the radiator back on, go ahead and put the air box back in. Reversing the same motion you used to get it out. It seems awkward but it will go. And finally pop in that last piece of air ducting on top of the radiator.

Whew, all in all that should have taken about 3-4 hours max. Seriously. I had to do some of this stuff 2-3 times because I would do one thing and then once I was in there learned I had to do something else. I just re-did all of this to take the new pictures and also install the new air intake. It took me 2 1/2 hours to do all of this. But doing all of these things at once may help you solve your problems and they all flow naturally together, are all really easy to do, and they don't cost a whole lot of money. The next group of projects involves getting under the car and they should all go together. That DIY mashup I will post later but it will include Oil change, Coolant flush, and fuel filter change. Those three really don't share much in common besides simply being under the car, but the projects I listed above can really benefit those looking to solve check engine light code issues.

A big shout out to the following DIYS from where I stole pictures and their instructions but added my own and mixed them up to make a real straighforward DIY that mixes all of them. If you are the owner of the pictures I used please let me know if you want me to take them down. I can replace but I'll have to go take my own pictures.

Good luck everyone.

Reply With Quote
Old 11-23-2010, 04:02 AM
zQUEz zQUEz is offline
Officially Welcomed to the 'Fest
Location: North Florida
Join Date: Jun 2010
Posts: 218
Mein Auto: 325i
wow awesome write up. This will be perfect to use this weekend for my ICV cleaning work planned. thanks.
Reply With Quote
Old 11-23-2010, 04:51 AM
aleks's Avatar
aleks aleks is offline
Officially Welcomed to the 'Fest
Location: Columbia, SC
Join Date: Dec 2008
Posts: 366
Mein Auto: 2004 330xi
Wow, this is going in the archives!
<(OO) ||| ||| (OO)> 2004 330xi ZPP Titanium Silver
Reply With Quote
Old 09-20-2015, 07:40 PM
Slimtexas Slimtexas is offline
Registered User
Location: Texas
Join Date: Sep 2015
Posts: 21
Mein Auto: 1999 BMW 323i
Amazing post

AWESOME!!!!!! This is Exactly what I was planning to do, but had no idea where to start or what exactly to do. Now I am confident and ready. My 323i is doing the same things you explained. And I know bmw's pretty much all go through the same issues as they age. Mine has 146,000 miles. So Yeah........ its time for an overhaul of the outer engine components. Mine wont even go past 50 mph, and it takes off like a hoopty. Thanks bro for the outstanding report. Wish I could High Five you!

Last edited by Slimtexas; 09-20-2015 at 07:41 PM.
Reply With Quote

See More Related BMW Stories

Forum Navigation
Go Back   Bimmerfest - BMW Forums > BMW Model Discussions > 3 Series & 4 Series > E46 (1999 - 2006)
Today's Posts Search
Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump

All times are GMT -7. The time now is 10:37 PM.

Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
© 2001- VerticalScope Inc. All rights reserved.