BMW E36 Blog

Cleaning E36 ICV (Idle Control Valve) . . . DIY!

23rd June 2007

Cleaning E36 ICV (Idle Control Valve) . . . DIY!

posted in Do It Yourself, Engine, Technical Info |


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Hi Guys,

 

Car hesitation and RPM bouncing are the most common problems between the BMW E36 cars. It seems that many cars have the problem and the problem is very hard to fix. I recall that even my previous E30 used to have the problem, but some how, the problem was solved. Maybe with something that I did and didn’t notice it fixed the problem.

 

Now my E36 318is is having the same symptoms and it gets very annoying especially when I turn my A/C on.

 

I started looking for a solution to this problem and it seems that cleaning the ICV (Idle Control Value) is one of the most obvious reasons for the problem, so I looked for a DIY about it and found one. The DIY is for M42 engines. I will be writing another post to fix same problem for the M50 engines. Please notice that I didn’t try this DIY myself yet, but I’m going to do it very soon.

 

Please notice that that cleaning the ICV will not always fix the problem, but it’s a very common reason, so if it didn’t totally solve your car’s problem, then you have other issues, but since the procedure is very simple, I guess everyone should start with it. Please follow the steps below and see if this fixes your car’s RPM bouncing problem. Enjoy ;-)

 

 

Disclaimer: Use this info at your own risk!! I’m not responsible if this didn’t work for you.


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!

 


Are you looking for more do it yourself procedures (DIY) ? I recommend the Bentley BMW 3 series service manual for you. I got it and I think it’s a gold mine for us -BMW E36 Owners-. If you didn’t grab your copy yet, get it right now! I’m sure you’ll find this book worth every penny you’ve paid for. Get the Bentley BMW 3 series service manual

 

Wait for more from BMW E36 Blog.

 

Best regards,

Tony Sticks.



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This entry was posted on Saturday, June 23rd, 2007 at 11:02 pm and is filed under Do It Yourself, Engine, Technical Info. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.

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There are currently 44 responses to “Cleaning E36 ICV (Idle Control Valve) . . . DIY!”

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  1. 1 On December 5th, 2007, Greg said:

    Hi,
    Just purchased e36 318is 1995. It suffered eratic idle and would some times run rich on startup. I found that car had suffered failed right hand engine mount, which was repaired. But what I found is that the failed engine mount had in fact caused premiture cracking of the inlet bellow style hose between throttle body and air flow air mass meter. This in fact more air entering engine than air mass meter ws measuring and stuffing up the critical balance of air fuel mix. Hope this helps and one who has similar problem. Check small hose that goes from bellow hose to icv as well see tony sticks post. regards Greg

    posted on December 5th, 2007 at 2:39 am

  2. 2 On December 29th, 2007, lee said:

    hi just joined the site i have a e36 320i m50 i was wondering if you knew where the camshaft pulse generator is located as i cant find anything on the net cheers lee

    posted on December 29th, 2007 at 2:28 pm

  3. 3 On January 5th, 2008, andy bonn said:

    hi.. this blog helps a lot.. i had a 318 1992 model. the idle really goes up and down sometimes. havent checked it yet. i also had a problem with the aircon when the idling of the engine was malfunctioning so with the aircon.

    posted on January 5th, 2008 at 4:23 am

  4. 4 On February 22nd, 2008, Kumi said:

    so did this stop the rough idle

    posted on February 22nd, 2008 at 9:29 pm

  5. 5 On February 24th, 2008, Tony Sticks said:

    Hi Kumi,

    Unfortunately, cleaning the ICV didn’t work for me. It made it a little better but what fixed the problem was the Oxygen Sensor replacement. Actually the problem with my idle is not 100% fixed, but it’s close.

    posted on February 24th, 2008 at 9:31 am

  6. 6 On March 20th, 2008, Johnny said:

    1995 318is **THIS HELPS**

    I had this problem as well. Very erratic idle that would go WAY up and then WAY down - even stalling. It was made worse when applying brakes, turning, using heat/AC. Check Engine Light would come on now and then.

    First try at fixing the problem: a new O2 Sensor – Didn’t fix it. But the check engine light went off, so I think it was a bad sensor.

    Second try: I had the same cracked hose Greg described in his comment above, and fixed that *This partly fixed the problem* car stopped stalling BUT the idle was still erratic, and it would stall a few times each time it was started

    Third try: Cleaning the valve as described here has smoothed out the idle and everything is working well now. No more stalls, nice even idle. Thanks!

    posted on March 20th, 2008 at 6:55 am

  7. 7 On March 20th, 2008, Tony Sticks said:

    Thanks Johnny for the detailed description of the problem and how to fix it.

    posted on March 20th, 2008 at 7:30 am

  8. 8 On March 30th, 2008, Frank said:

    Hey Guys,

    Just a little curiosity, Went for a drive in a highway yesterday, and when i got home, i smelt this rubbery smell somewhere infront of the car trying to sniff around cudnt figure out where the rubber smell came from but notice it only releases when i use more power or in a highspeed, any tips for these guys?

    Thank you.

    Frank :)

    posted on March 30th, 2008 at 3:24 pm

  9. 9 On March 31st, 2008, Tony Sticks said:

    Hi Frank,

    I think I have noticed this once or twice before, but honestly, I have no idea what’s causing it.

    posted on March 31st, 2008 at 8:16 am

  10. 10 On March 31st, 2008, Frank said:

    had the car at full service today, and that rubbery smell we thnk its from the engine somewhere (overheating causing some rubber to breakdown-had it on sportsmode) while as the mechanic also notice the fan (radiator?) isnt working at all, not until he took off the sensor it start spinning again. Also the water cooler in the right side isnt warming up too which he said causes the fan to not to function at all (which he also find it weird), anyways, we ended up unscrewing the water tap slowly after the test drive and brought up some air stuck inside which he thinks the “cause” but somehow after those air got brought up, water cooler in right side start to heat up again and that suppose to fix it however 10 mins laters in the traffic, it started kinda having trouble reving up (as its usual mode of this car)obviously the radiator isnt fix and is still malfunctioning, at same time refuses the engine to produce more power????
    o god, sorry about this explaination if it isnt clear enough, so not mechanically minded….

    Thanks

    F

    posted on March 31st, 2008 at 3:22 pm

  11. 11 On April 1st, 2008, Tony Sticks said:

    Frank,

    Try to check the coolant level in your radiator now and see if it’s went down or not. Please make sure the car is cold before you do this.

    posted on April 1st, 2008 at 9:38 am

  12. 12 On April 2nd, 2008, Frank said:

    Yeh, check it this morning, it went about 6-8 inches down after got filled up, so i re-fill it anyways. Does that makes a difference? It also funny coz after a long drive my radiator isnt spinning….

    posted on April 2nd, 2008 at 12:13 pm

  13. 13 On April 2nd, 2008, Tony Sticks said:

    Hi Frank,

    There’s a mark on the radiator reservoir which shows where the coolant level should be, make sure to fill the reservoir to that mark and check after one day or two. Maybe you have a leak somewhere.

    posted on April 2nd, 2008 at 2:28 pm

  14. 14 On April 3rd, 2008, Frank said:

    yeh at the moment i got an oil leak, but does that connect to the radiator’s part?

    yeh i will keep an oil on that water level.

    posted on April 3rd, 2008 at 6:30 am

  15. 15 On April 3rd, 2008, Tony Sticks said:

    Oil Frank? You mean coolant, right?

    posted on April 3rd, 2008 at 8:48 am

  16. 16 On April 3rd, 2008, Frank said:

    o god sorry tony, yeh coolant….. :S hehe. I been keeping an eye on that.
    but yeh oil leak is also a little problem. thinking of bringing this to bmw mechs.
    My main question about this car is, it takes so long to reach 60km sometimes, that happen so often that i made a little traffic behind me and half a time people just overtake. I dont understand all these tehcnical stuff but i just need to know why does it start real slow. is this normal bmw probs?

    posted on April 3rd, 2008 at 9:49 am

  17. 17 On April 3rd, 2008, Frank said:

    I know it’s a wide range question but do you kno how many hours does it take normally to fix engine/transmission problem? just approximately.

    posted on April 3rd, 2008 at 9:52 am

  18. 18 On April 3rd, 2008, squid 66 said:

    Has any one ever taken the fuel tank out of a 318IS, I have to. I have a small fuel leak on the breather line coming from the fuel tank. It only leaks if tank is over half full and heavy braking or cornering. The 318IS has a purge tank which has a 8mm breahter line going to engine bay canister.
    Now to remove fuel tank to get to breather lines I have to remove drive shaft, exhaust pipe with cat and disconnect park brake cables from wheel assembleys. I am planning this job for a few weekends time so I let you all know how I go. If any of you have any tricks please advise. My 318IS has lowered Kings Suspension, M3 body kit and M5 17″ rims. I have only seen 3 like that here in little old Adelaide South Australia…..

    posted on April 3rd, 2008 at 12:03 pm

  19. 19 On April 3rd, 2008, Tony Sticks said:

    Hi Frank,

    I’m not sure if the coolant leak in your car would make your car that slow. I think you have more than one problem. I suggest you run a diagnosis for the car to find out what’s wrong with it.

    About the coolant level, it should stay at the max mark on the reservoir. If you’ve noticed a drop in that, I suggest you check your radiator and reservoir for possible cracks.

    Oh yes, about the time it requires to fix the engine and/or transmission, I guess it depends totally on what kind of problem that you have.

    posted on April 3rd, 2008 at 4:11 pm

  20. 20 On April 3rd, 2008, Tony Sticks said:

    Hi Squid,

    I’m sorry I can’t be of much help to you. But I would appreciate if you give us any update about how this will go. Good luck!

    posted on April 3rd, 2008 at 4:17 pm

  21. 21 On April 8th, 2008, Frank said:

    Hi Tony,

    Yeah i totally agree, seems to me that this car have heaps of probs. I mite talk to
    mechanics about diagnosis test, just dont want to go there feeling like im lost
    in the woods or something and rip me off after.
    Anyways i’ll b in touch.

    Thank you for your help Tony.

    Frank

    posted on April 8th, 2008 at 9:28 am

  22. 22 On April 8th, 2008, Tony Sticks said:

    Frank, I suggest you run the diagnosis, but don’t fix anything before doing a little research. This way, they won’t be able to rip you off ;-)

    posted on April 8th, 2008 at 3:23 pm

  23. 23 On April 9th, 2008, Frank said:

    Im mite be sounding like a rookie here but, what do you do to run the diagnosis test?

    so sorry man.

    F

    posted on April 9th, 2008 at 8:49 am

  24. 24 On April 9th, 2008, Tony Sticks said:

    It’s ok Frank, no problem :-)

    Any decent BMW service garage will have a specific device for the diagnosis. It looks like this

    They will connect it to your car’s diagnostic data port (under the hood) and run a diagnosis. After that, the diagnosis device will show all the problems that have been found.

    posted on April 9th, 2008 at 10:48 am

  25. 25 On April 10th, 2008, Frank said:

    is it only the bmw mechs have those device? i got mine booked in with automotive specialist, they have a descent garage area however
    they not that big company, just the people next door where i work
    coz i’m not sure if i really need to bring this vehicle to bmw mechs but did some observation in the vehicle
    and notice these:
    - having trouble changing gear in 3-4th gear (or take a while too)
    - sometimes, starts real slow from traffic lights that worst if its on a hilly road.
    - if air/con has been on for a while and next time i unlock the car, alarm would go off.

    Thank you.

    posted on April 10th, 2008 at 8:57 am

  26. 26 On April 10th, 2008, Tony Sticks said:

    Hi Frank, this device is not designed for BMW cars only. It can run diagnosis for many brands. So, I guess you have to ask them if they have that device. One more thing, I suggest you run the diagnosis before doing anything else.

    posted on April 10th, 2008 at 10:10 am

  27. 27 On April 18th, 2008, Dallas said:

    hey, stumbled across this page after i’ve been having some similar issues with my beemer, hopefully someone might be able to assist me..
    I have a 1993 Automatic 320i E36 down here in Brisbane Australia. Almost 185000 kms on the clock.
    Started having some issues with it at the start of the year. Worst issue so far I was accelerating and the rev’s started jumping up and down (approx between 500rpm and 3000rpm), car started to lose speed and would not accelerate. Pulled it over and turned it off. Tried to turn it on and first few attempts were unsuccesful. After trying for several times after the car finally turned on how ever the ignition sound was very rough and took ages to start. When it was on, the car was also shaking more than usual at idle, hard to explain but when it happens you know its bad. I turned the car off and gave it about 20 minutes to rest. Turned it on again and it started fine, drove it about 5 minutes down the road and it started to play up again. Rough idle at lights with the feeling its about to stall, was losing power also, then wouldn’t start again. Ended up getting it towed. Took it to a mechanic the next day and they couldn’t duplicate the issue, and the car was running fine all day. Couple of days later it did the same sorta thing again whilst accelerating up a hill, how ever i wasnt far from home so the car managed to make it.
    Car was recently serviced at this time. My Fan controller, or whatever it is called, requires replacement as the fan does not spin as fast as it should be but I wouldn’t think that would cause this issue. I also get rough idle with the A/c on, as well as other random times. Since then I haven’t had any real issues whilst driving the car :s. Very annoying though as Im’ not sure if this problem ‘fixed itself’, or is likely to reoccur randomly.
    Found in my drive way today also a hose about 30cm long sitting under my car with several holes in it. No idea where it came from lol, hoping it might have something to do with my issue. I’m going to get a mate to check where the hose came from on the weekend as I dont have much ‘engine experience’.
    My apologies if none of all that makes sense :P.
    If anyone is able to suggest some possible things to look at relating to my problem that would be greatly appreciated.
    Cheers

    posted on April 18th, 2008 at 11:34 am

  28. 28 On April 18th, 2008, Dallas said:

    Update. Just took it to a mates place who also has the same car as me and does alot of DIY, and found the hose which had failed and broken in half. Pic is attached with a circle around each end of where the hose should be. The hose was also fractured in several places with small holes particular where the hose bends. Does anyone know if this may have been the cause to my issue outlined in the previous post? enginebay :

    Thanks

    posted on April 18th, 2008 at 12:22 pm

  29. 29 On April 18th, 2008, Tony Sticks said:

    Dallas, did you try to replace that hose and see if that will solve your problem?

    posted on April 18th, 2008 at 4:57 pm

  30. 30 On April 29th, 2008, Andy said:

    Thats the breather hoose for the crankcase ventilation, since you have som oil leakage you should by a new O-ring.

    posted on April 29th, 2008 at 12:59 pm

  31. 31 On May 30th, 2008, DG888 said:

    hey Dallas.. problems with the crankcase ventilation or associated hoses will definitely cos erratic idling.. hoses do crack due to aging.. power loss and engine cut off during driving can also be due to worn out oxygen sensor.. it is recommended to change that sensor every 50000km or so…

    posted on May 30th, 2008 at 4:32 am

  32. 32 On June 18th, 2008, ukfrog said:

    Hi Tony, and everybody else.

    I have an other problem with my 325i 1993 M50 None vanos.
    My idle is chucky and I’ve looked at everything I can think of, but nothing seems to sort the problem out!
    I have cleaned the ICV sensor, thnaks tony for detailed post. I changed the TPS, and also the O2 sensor, I checked for air leaks on all hoses, and on the intake manifold, I’ve checked that the MAF was working. I also had the garage check plugs and injection system, I also cleaned the throttle plate and housing.
    Now all the above work fine, I have no show on fault codes at diagnosis, but I still have chucky engine.
    Can someone point me in the right direction please?

    I have made 2 videos, one from the engine bay, the other at the exhaust end, the second is because you can hear the sound a lot better from there.
    The videos are posted on youtube on the following link.

    http://www.youtube.com/user/E36ukfrog

    Could you please come back to me with your thoughts about this, and post your views.
    At this stage, any help is welcome!!! LOL
    Thanks all.

    posted on June 18th, 2008 at 11:39 am

  33. 33 On June 20th, 2008, Don said:

    Wow! This worked perfectly. It took about an hour, start to finish, and the car runs great.

    posted on June 20th, 2008 at 5:16 am

  34. 34 On June 20th, 2008, Andy said:

    okfrog

    That sounds like missfiring, could be a coil bad coils are not always shown on diagnostiks test.

    posted on June 20th, 2008 at 10:53 pm

  35. 35 On June 21st, 2008, ukfrog said:

    @Andy
    Quote[That sounds like missfiring, could be a coil bad coils are not always shown on diagnostiks test.]end Quote

    I just finished testing Voltage and Resistance on the coils, the all in good working order.

    The reading I got was 9.70V and a even 0.5 Ohms per coil.
    This metting the Bosch Chart, I take it they are working…
    Thanks for idea anyways…I think now it was a Manday or Friday car GR*@*#RR

    posted on June 21st, 2008 at 2:05 am

  36. 36 On June 21st, 2008, ukfrog said:

    Read “Monday car” in previous post.
    Eye, brain, fingers, coordination problem, if you see what I mean?
    LOL

    posted on June 21st, 2008 at 2:11 am

  37. 37 On June 21st, 2008, Andy said:

    I have an idleing problem and crack in the window, will probalby send it to the junk.

    A shame its a nice 525 , but a killede my catalytic converter beacuse i did not change my tempsensor.

    and gasprice is awful, but i love the its best over 5000 rpm =)

    posted on June 21st, 2008 at 2:13 am

  38. 38 On June 21st, 2008, Andy said:

    do you have a gas spell or something, checked for a leaking fuel rail?

    posted on June 21st, 2008 at 2:15 am

  39. 39 On June 21st, 2008, ukfrog said:

    @Andy

    No, No gas leaks. I think I has to be related to the intake somehow. I just changed all the plugs also with no change in the idle. The head is new so head gasket, and intake gaskets are new. So somewhere else in the intake. Or electrical but from faulty sensor, maybe stuck or broke down on setting that will let the car start and run but shorting a circuit or giving wrong reading….But not showing on code because it looks like it’s still working.

    posted on June 21st, 2008 at 2:28 am

  40. 40 On June 28th, 2008, Sasha said:

    Hey guys!

    I dont know if anybody had this problem or not, my electrical shift control light came up yesterday, and then car shifts into 4th gear, (automatic)

    So i searched online for the answer and I didnt find anything, besides, it migth be throttle control sensor, or something like that. after replacing that I still have the same problem, Sometime thow when I turn the car off and start it again the light will go off, and then as soon as I will drive up the hill the light will come up again and i will be in 4th gear again, So did anybody had simullar problem??? any advice how to fix it, please let me know, i dont want to take to a diller when its might be just a little problem, thanks,

    ///Sasha - 92 325i

    posted on June 28th, 2008 at 12:56 am

  41. 41 On June 28th, 2008, ukfrog said:

    @Sasha
    Check your transmision oil level.

    posted on June 28th, 2008 at 10:34 pm

  42. 42 On July 3rd, 2008, Harout said:

    I noticed something in the very first photo that could contribute to the rough idle problem. The intake air duct has a long crack on the third bend from the left. Chances are that if the crack has penetrated through the duct it becomes a major source for vacuum leakage.

    On my car’s engine the duct had two long cracks and the accompanying extremely rough idle. I used duct tape and plastic ties to seal the crack temporarily. It fixed the rough idle problem completely.

    Needless to say I’ve ordered all the flexible ducts and vacuum hoses that are part of the air intake system, just to make sure that there is no leak in the system.

    1995 318ti

    posted on July 3rd, 2008 at 6:53 am

  43. 43 On July 3rd, 2008, BMW E36 M42 DISA Valve | BMW E36 Blog said:

    [...] with my BMW E36 318is idle and until now, I was unable to totally fix the problem. I’ve cleaned the ICV, changed oxygen sensor, checked for vacuum leaks but this didn’t solve my problem. I still [...]

    posted on July 3rd, 2008 at 5:35 pm

  44. 44 On July 3rd, 2008, Tony Sticks said:

    @Harout: Wow! thanks for noticing this. You know this may be causing the whole problem in that car. But as you said, it may not have penetrated the air duct like in the case of my car. My had a tiny crack like this, but I changed it anyway and it didn’t enhance my car’s idle at all.

    posted on July 3rd, 2008 at 5:46 pm

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