Idle Control Valve

nut11 · 09-06-2008, 10:28 AM

I have a 98 328is w/ 124K and a newly replaced MAF. The install fixed rough start/low idle problem but now she has erratic idle running on the high side. Would like to clean ICV as a next step and just need to know if there's a way to locate unit w/o removing intake manifold. Any help is much appreciated. Would rather not tackle the intake if I don't have to. The car is a sweetheart.

Jeron · Jeron's Garage

It's tough to see and a bit hard to get to but I can remove my ICV without removing the intake. Mine was bolted to the flange that the upper oil dip stick tube is bolted to.

nut11 · 09-08-2008, 12:40 PM

Thank you for your reply. Will attempt tonight and keep you posted.

nut11 · 09-13-2008, 11:26 AM

Jeron: Mucho thanks. Just finished the job and she's purring like a kitten. It was the ICV and boy was it dirty. Carb cleaner, let soak and finished w/ a wisp of WD 40. Once cleaned, you could see and feel the internal mechanism swiveling. Tricky to get at but your COA was on the mark. Again, thanks.

98 328is
87 blk carrera coupe

Jeron · Jeron's Garage

Good to hear you got it fixed.

nut11 · 09-15-2008, 03:07 PM

Well..., sometime exuberance exceeds reality. The fix didn't last. Next step will be to order a new ICV from our host and hope it does the trick (I hate chasing etronics). Not having an omh meter hurts as I should have tested resistance. The silver lining is that the valve replacement install should be straight forward (been there done that). If the new valve doesn't work, I'll holler... I appreciate your keeping track.

87 blk carrera coupe
98 328is

Jeron · Jeron's Garage

Describe the problem you are having. You said erratic high idle. Does the idle get better when warm? Does the idle wander while driving?

nut11 · 09-16-2008, 12:40 PM

Engine immediately races to 3000 rpm upon morning start up (50 degrees F.). Then settles down w/ me putting it into gear w/ foot on brake peddle slowing the engine down to 1000 rpm. That done, it settles down until the engine warms up and it then bounces b/t 1000 and 2000 rpm at rest until, again, I put the tyranny into gear w/ foot on brake peddle and slowly bring down idle to 1000. I repeat this at every stop light. It's a PITA. BTW, haven't yet done a smoke test for vacuum leaks. Thanks for any insight.

Jeron · Jeron's Garage

That's a new one to me. But its unique enough that you should be able to find the answer.

I would start with checking the mechanical operation of the throttle body and cable.

nut11 · 09-16-2008, 03:39 PM

Roger that. Will check throttle body and cable and keep you posted. Thanks.

hitmachine101 · 09-24-2008, 08:14 AM

Got a similar question Jeron,

Just replaced my MAF and i am still having a serious stalling problem and rough low idol, i was reading this thread and you said the ICV was next to the dip stick under the intake manifold?? is this the same place where it would be on a M3 97?and if yes should i clean it out with carb cleaner and wd40?

Jeron · Jeron's Garage

Quote:

Originally Posted by hitmachine101

Just replaced my MAF and i am still having a serious stalling problem and rough low idol, i was reading this thread and you said the ICV was next to the dip stick under the intake manifold?? is this the same place where it would be on a M3 97?and if yes should i clean it out with carb cleaner and wd40?

That's where it is on my 97 M3.

It's hard to see. It's the three bolts on the bracket the top of the dip stick tube attaches to. One of the three bolts holds the dip stick tube as well, IIRC.

I would clean it with carb cleaner, let it dry and follow it with light oil, like you said.

Start by check ing for vac leaks, loose hoses, cracked intake tube etc.

hitmachine101 · 09-24-2008, 11:29 AM

ok found the spot where your talking about, is the idol control valve behind it? do i remove the three screws to access it?

Jeron · Jeron's Garage

Yes it is essentially behind it. It is a big metal cylinder just smaller than a fist with a big (1/2"-3/4") hose coming out of it that runs to the intake tube.

hitmachine101 · 09-25-2008, 05:02 AM

wow this is a tough one to get to,, once i do get the screws removed and the metal plate off, how do i go about cleaning it, i see the large cylinder underneath the plate... just give the entire thing a good squart with carb cleaner?? and make sure the hose thats going to the intake is secure and tight??

Jeron · Jeron's Garage

Once you get the 3 bolts off it will come out. The ICV has an opening that friction fits up into the bottom of the intake, just twist it out. The big hose will disconnect either at the ICV or the intake tube.

Once its out clean it thoroughly.

hitmachine101 · 09-25-2008, 06:06 AM

ok great, ill tackle that this afternoon

thanks for all the help

nut11 · 09-25-2008, 03:34 PM

Hitmachine101: Hope it works. Good luck.

I haven't yet ordered a new ICV for my application (too much traveling w/ work lately) having already cleaned the original and still need a smoke test but it seems to me (for Jeron) that if I can stabilize the idle using the clutch then I may not have a vacuum leak b/c the idle does stay constant once I use the clutch. Further, I checked mechanicals w/ the throttle body and all appear sound plus b/c it's an electronic throttle it's very arcane for me to grasp as to how the frigger works. I don't think there's any way to rev the engine from the engine bay that I'm aware of w/o going underneath the throttle body and scraping a knuckle or two. Bottom line: I'm desperately hoping a new OEM ICV does the trick. Wish me luck and I will keep you posted. The car's so nice to drive and this is so annoying... Thanks.

Hottxshott777 · 11:18 AM

Nut11:
(I have an 1987 325e),
but I am experiencing the same problem. I haven't braved more than a half mile of driving. we replaced the mass air flow sensor and checked the throttle valve switch, checked the vacuum hoses and still haven't found out the problem or its solution.

I sure hope your ICV fixes it, if it does please let me know.

it could fix my problem.

Lucas

Jat007 · 04-14-2009, 07:47 AM

Say, where are you guys with this issue? Fixed or no fixed??

I was just wondering since my 92' is behaving the same symptom and not sure where to go from here.

Thanks,

J

Quote:

Originally Posted by Hottxshott777

Nut11:
(I have an 1987 325e),
but I am experiencing the same problem. I haven't braved more than a half mile of driving. we replaced the mass air flow sensor and checked the throttle valve switch, checked the vacuum hoses and still haven't found out the problem or its solution.

I sure hope your ICV fixes it, if it does please let me know.

it could fix my problem.

Lucas