[magicmart]

Hi Guys/Girls.

I'm new which probably means I will be crucified for daring to ask something that is probably hidden away on some obscure thread that is impossible to find (joking)

I recently had some trouble with a rough and erratic idle when the car was warmed up. I put this down to the Idle Control Valve possibly needing to be cleaned.

I got a guide off an American BMW forum that I accidentally joined in error (hope no one else makes same mistake) on how to remove the ICV and after being totally terrified by the amount of stuff the guide said I should take off, I went and had an actual look at the location of the ICV and after removing the throttle body and inlet elbow for ease of access, was able to just reach under and remove it with the whole process taking less than 5 mins and without taking off the inlet manifold and fuel lines and what not. Refitting ICV after cleaning also took less than 5 minutes.

So anyone who wishes to remove/replace their ICV would maybe like to consider my approach which unless you have hands the size of dinner plates is far easier than spending 3 or 4 hours stripping down your inlet manifold and cutting rubber bits etc .

Well anyway now if anything the rough and erratic idle has worsened and I did notice as I was cleaning the ICV that there was no resistance in the little flap or gate type bit that obviously must open and close when required to. I'm wondering if this is normal and if the ICV unit itself is faulty?

Many thanx in advance for any info anyone can give and I do apologise if I've asked something that has been answered a million times but in my defence I did search the forums but found no suitable threads

 

[xXNealXx]

Yes magicmart, this topic has been covered numerous times. We had a member who cleaned the ICV and did not cure his erratic idle, just as you have described. So he bought one from a breaker and it cured his problem. So hopefully, that answers your question :thumbsup

 

[magicmart]

Many thanks.

I thank you kind sir for your assistance.

I've just been out again checking the vehicle and it is ticking over or rather chugging over at around 500rpm. I disconnected the plug from it and then it seemed to idle lovely. So yes it seems like it is a faulty ICV. I have managed to find another ICV from a local BMW breakers for £25 so hopefully after installing it she'll be sound.

Many thanks:thumbsup

 

[magicmart]

Still not fixed it.

confused

Fitted another ICV and the problem is still there. What can it be? I'm well stumped. I sprayed carb cleaner in the general area of the Inlet manifold and the revs picked up...particularly when I sprayed near a canister looking type thing directly underneath the inlet manifold and close to the ICV.

Any help at this stage would be much appreciated. I thought the ICV would sort it:frown

It's very frustrating:banghead

 

[steve23002]

If the revs are picking up after spraying carb cleaner it means you have an air leak somewhere around the inlet and its drawing unmetered air.
I would check all the rubber hoses for any loose or split. :thumbsup

 

[xXNealXx]

Did you check for any airleaks before fitting the ICV? I assumed you must have done.

 

[wootty]

sounds like an unmetered air leak (engine side of the maf) if you swapped the valve over.listen for sml hissing sound if poss.

 

[magicmart]

Before all the messing with the ICV, I did used to notice on shutdown and sometimes just after revving a hiss (similar to dump valve) from what I now know to be the Crankcase Ventilator/Oil Separator. I cannot see any visible air leaks. I did have a quick check prior to removing ICV.

Are these Crankcase Ventilators known to play up in this manner?

 

[wootty]

in my opinion these crankcase vent/filters can be a pain.id rather go straight to atmosphere with them,but it can give crap ecu readings on the emissions side.
i dont think the crank vent pulls air in anyway,rather than blow out.i could be wrong.maybe ronnie can shed some light if he sees this thread.

 

[Ronnie]

There should be no leaks from the crankcase vent valve, if you spray carb cleaner around it and it picks up then it's knackered. All air should travel past the Airflow meter, otherwise the engine will run lean if it gets in "illegally" :hihi