Idle Control Valve Write up; ICV clean DIY

[Mr.M]

Note: If you cannot see the images, please PM me for them and I will email them to you.

So I did a search on cleaning the idle control valve and came up with question threads that had no answers. The DIY on bimmerDIY is essentially useless, so here’s one I hope will be of more use to M42 owners

If your idle is rough, changes rpm's, or just fails to keep the engine running, your IVC may be clogged and in need of cleaning. I was having a slightly rough idle and decided to do mine.

This DIY / write-up will require the following tools/supplies:
Flashlight would be helpful.
11mm socket
Flathead screwdriver
Throttle body (TB) cleaner
OEM hoses if in need of replacement
Throttle body gasket and intake manifold gasket (not technically necessary, but a good idea)

It took me about an hour to remove, clean, and put back the ICV. Plus I let the hoses dry (while out of the car) for about 20 minutes on top of that.

First, start by opening the hood with the engine off and hopefully not too hot, as you will make contact with the block and the intake manifold.

You will take off the intake tube, shown below, by loosening the screws at the blue arrows, and pulling off the hose at the red arrow. Then pull the intake tube off completely.



Next, you remove the throttle body, by four 11mm bolts. The top two are shown with red arrows below. The bottom two are on the bottom of the TB, in the same position as the top two.



Move the throttle body off to the side, to gain access to the upper intake manifold, like this:



Next, we'll disconnect the hose connecting the manifold to the ICV we wish to remove and clean. Behind the manifold, at the back of the engine bay, is the hose. Just twist it off, as shown by the red arrow.



Now it's time to remove the upper intake manifold. Undo all 5 of the 11mm nuts attaching it to the lower manifold. The nut locations are highlighted below with red arrows. The nut in the rear of the engine bay is hard to get to, but a small 11mm socket and 1/4" drive ratchet should get it out.



Next, carefully remove the manifold, by slowly lifting it up. I pried it off woodworker style using the backside of a hammer against the block. Be sure to remove it evenly though, lifting it up equally on all sides. Otherwise it will get stuck on the bolts on the manifold's drivers side. It is easiest to place it as shown:



Now we have acces to the ICV. As shown below, it is attached with a rubber strap at the point shown with red arrows. The blue arrows indicate the electrical connection, which pulls of when you press down a wire clip. They also point to the hose connections, which you will also want to remove. Note the arrow on top of the ICV. It points TOWARDS the block. The part label with Bosch and the BMW part number written on it also face the front of the car. This is important. You want to put it back facing the correct direction.



Now, take the ICV and clean it. The image below shows the ports into which the tubes were plugged, and air flows, with a blue arrow. You'll want to hit it with an old toothbrush and a gratuitous soaking with the TB cleaner. You may choose to clean the throttle body itself while at it with some paper towels and the cleaner.



Let everything dry, and clean off the hoses if you'd like. One of mine was cracked and therefore replaced, but washing the oil and grease off of them will help them last longer. Replace any that are cracked! They will make your idle worse and allow unfiltered air into the engine = bad. Be sure to let everything dry, especially items that were cleaned with water (hoses.) Installation is the reverse of removal. Be sure to connect ALL the hoses - double check!

And you're done! My idle was substantially smoother and more consistent. It made a huge difference! Good luck, and PM me with any questions, or if you are having trouble viewing the image.

Regards,

-Robert

[prophecy]

yes it will be similar on an m50, you'll be taking of the intake manifold and the airbox most likely unless you have like spaghetti hands.. its simple once you get to it

[Mr.M]

It should be pretty similar. There was a similar write up for the M50 on the forum, but when I looked it up all the picture links were dead

[Green318is]

In my car the ICV seems to be located in a different place than yours. It's not below the intake manifold. It's farther to the back, near the oil level dipstick, just as TC535 explained. Check picture 24 on page 130-16 of the Bentley manual. My car is a 1993 318is (Euro version). I can remove it without taking out the intake manifold.

[TC535i]

In my car the ICV seems to be located in a different place than yours. It's not below the intake manifold. It's farther to the back, near the oil level dipstick, just as TC535 explained. Check picture 24 on page 130-16 of the Bentley manual. My car is a 1993 318is (Euro version). I can remove it without taking out the intake manifold.

Mine's a '92. Seems like they made some changes to the M42 between the 92/93 models and the 94/95 ones, maybe this was something in that revision?

[shanecconn]

just noticed there that my hose going from the intake hose to the icv ain't branched like MRM's , whats that about , everthing else was the same.

[shanecconn]

also, i forgot to reconnect the hose connecting the manifold to the ICV and my god the car sounded awful when i tried to start it. i thought i'd just made my sitution a whole lot worse by cleaning the icv. god i was happy to see what i'd done wrong.

[Mr.M]

There are some small revisions that were made on the M42, and some big ones like the profile gasket fix. I believe the profile gasket was fixed with '95 models? If so, that would explain why everyone seems to have minor differences compared to my DIY: you all have 94's and older.

[antonk]

I just cleaned the ICV on my 92 318iS, and man was it ever easy to get to. You don't even need to "get" to it, it just sits there behind the exhaust manifold. Just take off the electrical connection, and the two hoses, undo the one nut and it's off. 5 mins of cleaning, and pop it back in. Easiest thing I've done. Car now idles smooth as a baby's bottom at least when the engine is warm. I JUST did this, so I've yet to test it cold, but I'm happy with how it idles when warm, because it's perfect. I guess there some benefits to 92s afterall

[psyyambmw]

Just see yr thread. Truly dedicate write up, especially m42ers.

However, I'd like to make a comment, over here. Hope U don’t mind.

When I doing this, I will not take the throttle body off. On the other hand; I will;

1st, remove GAS & Cruise Control plastic cable retaining and the o-ring rubber.

2nd, remove the plastic cable-end retaining clip. Take it easy, don't break it. Pull the cables out of the housing, respectively.

3rd, remove the vac hose.

4th, remove the throttle sensor plug.

Then, just remove'em, upper intake + throttle, as a one whole piece.

[mdh]

The ICV can be removed and replaced on an M50 without removing the intake manifold. It is a tight fit to get your hands in there but I have personally done this twice.

[Goon]

Just did this on my M43. The directions were easy enough to follow. Thanks for that. Oh and for the record, i took off the ICV without removing the upper intake manifold.

Cheers for the write up, all writeups should be as good as this one!

[dough boi]

The ICV can be removed and replaced on an M50 without removing the intake manifold. It is a tight fit to get your hands in there but I have personally done this twice.

Yup, I've done it without taking off the manifold, it's a tight fit, but unless you have HUGE arms/hands (mine aren't exactly small) you can pull it out, just takes some creative maneuvering, theres two hoses to connect to the IVC, leave them connected to the ICV, and disconnect them at their ends, I don't remember off the top of my head where they are, but one is connected to the manifold, underneath, right behind the throttle body, and one I think is connected to the intake piping? I found a DIY on here that pretty much walked me through it. I'm sure you can find it too. Took me about 30 minutes, including a few smoke breaks (like I said, creative maneuvering).

[frost dxb]

For some, cleaning ICV may not fix rough idle so don’t forget to clean this valve too (yellow circle) as this controls some vacuums too.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p></o:p>

[frost dxb]

There will be 2 allin key underneath the black plastic valve cover just undo them. I used a carburetor cleaner as there was a lot of dried oil evaporation from the head.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p></o:p>
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If you are using a full synthetic oil chances of oil evaporation will be minimized.<o:p></o:p>

[vml]

^I didn't know that! What's the part called? Oh and thanks to everyone who made suggestions/corrections to the original post

That part is the "crankcase vent valve" which is BMWspeak for PCV valve. It's a one way check valve so you can check if it works if it lets air in one direction and not in the other.

[jdbeast00]

This was extremely helpful. My car has been stalling for 3 years now. I cleaned out the valve as good as possible, so we'll have to see if that does the trick or if I need a new part. So far so good, but winter is the real test.

By the way, I read that your idle isn't supposed to budge when you roll up the window, etc. Is this correct? (for me, when my window reaches the top the idle takes a little dip)

Anyhow, I also just found realoem.com. What a lifesaver. Can't tell you how many times I had ot stand in line at a dealership trying to explain some random part.

On a side note, does anyone know what tool I need to tighten this:
(part number 16-13-1-379-229-M249 on pelicanparts...I don't have permission to post links)

Thanks again

[ryan319]

For some, cleaning ICV may not fix rough idle so don’t forget to clean this valve too (yellow circle) as this controls some vacuums too.<?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p></o:p>

i have a 93 318is (euro model) with a 1.8L. my car has been stalling at red lights and i want to clean the icv. i just looked at it and at the top where the hoses go, the inlet and outlet are at a 90 degree angel. they are not straight like the one in the picture. does my car have the wrong icv on it?

[Cyrix2k]

Are the instructions the same for an early M44?

[kas007]

ICV on 96 M44 is mounted to throttle housing - in plain sight. After a painful, and embarrasing, search under upper intake I discovered the ICV right under my nose. Two torx screws and 5 minutes later I was done.

[bigbilly]

For those with M52 engines wondering if you need to pull the manifold for this - you don't.

I pulled out my handy Bentley manual (seriously guys - if you don't have one,- get one, it saves a lot of time and really isn't that expensive) and looked for the M52. I think it's section 130, and note that there are three entries in this section for the ICV (for the different engine types). It's not well marked, but the M52 is the third/last entry for the ICV.

Cliffs notes for this:

1) Disconnect the "elbow" leading into your throttle body (or ASC throttle if you have it) and put aside. Remember that there's a hose attached to the bottom of the elbow, that connects the ICV to this elbow. This hose is important - you'll use it to find/remove the ICV later (below).
2) Using 10mm socket, remove the four bolts holding the throttle body on to the manifold. You may want to use a magnetic insert in your socket - you don't want to drop these bolts!
3) Pull the throttle body out of the way - but don't disconnect any hoses/cabling. I found it easiest to slide forward, towards the front of the car.
4) Look under the manifold and you'll see a support bar with two more 10mm bolts (these are shiny gold/silver metallic). If you're having trouble, follow your oil dipstick down - it attaches to the same support bar.
5) Pull these 10mm bolts and set aside. Push the dipstick aft, towards the driver compartment.
6) Using the hose mentioned in step 1, pull down and the whole ICV should come out. It's connected to the underside of the manifold by a gasket. It also has an electrical connection - push on the metal spring and pull the plug off.
7) Remove the clamp attaching the hose to the ICV and you're home free.

Tips for reinstalling:
1) When putting the hose back on the ICV, there should be some indentations at the top that fit "wings" or tabs on the ICV. Be sure to line these up or your hose won't be in the right place!
2) Probably the hardest part is lining the gasket back up with the hole in the base of the manifold. Use the bolts as a guide to determine where the ICV needs to be fore/aft, and you'll figure it out. No matter how hard this is, be thankful you didn't have to pull the manifold and you'll eventually get it to fit.

I took some pics - I'll try to post later when I can access photobucket.

My car started stalling terribly on Sunday, so I figured I'd give this a whirl and it worked like a champ. Looking back, the hardest part of the whole thing was driving with all three pedals to keep my RPM's up and not stall at the 15+ stopsigns/lights between my house and the auto parts store!

Good luck.

BB

p.s. If you've got the tools handy, it shouldn't take more than 15 minutes to pull the ICV out. Whole process - including cleaning - should take 45 mins to an hour.

[bosox1134]

i have a 91 3181s and the idle control valve was at the back of the intake manifold right next to the firewall and i didn't have to take anything out but one bolt

[wendall@cmwerks]

when you have the ICV out and all of the hoses disconnected, can you shake it and hear the valve open/close (rattle/click)?

I swapped mine last night and cleaned the one I put in before I put it in. I could hear both of them make a clicking noise when I shook them.

Just wondering if this was normal or do I have two bad valves.

[ChuckDizzle]

another thing to check for is a vacuum leak from the Crankcase Ventilator(CCV). Cleaning it may solve the problem for a while but they tend to leak and that just needs an overall replacement, its not expensive. $36.50( w/ employee discount ) I replaced all the gaskets on the manifold to fix my idle problem and then put up a smoke machine and saw that the CCV was leaking, it didnt look like it was leaking prior cause there wasn't enough pressure cause all the gaskets were screwed to begin with.

[Viper3812]

Could someone get me the part number to these 2 hoses please?

Thanks.