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Discussion Starter · #1 ·
Okay guys,

I've been having this issue for about a year, but it seems to be getting worse, especially as the weather warms. So when I am slowing down and push the clutch in and don't engage a gear right away, sometimes, it will drop down almost to the point of stalling and then bounce around before settling on normal idle. Other times, it will actually stall (it's happened to me 4x since in two years). It actually happened tonight. I was coming in a little bit hot onto an off ramp and the car stalled when I was downshifting to third (but rode clutch for a moment cuz car was in front of me). So first thing I noticed was power steering gone. I immediately put my flashers on and tried to restart, which may or may not have been a good idea since I guess I could have locked up my steering wheel (not going that fast at this point). So anyway, I pull onto the shoulder of the on-ramp, wait five seconds and she fires right back up. So on a deserted street, I decide to test, and rev up to 3k rpm, then clutch in. Sure enough, I watched her bounch all over between 200-500 before settling to normal idle (650 or so).

SO, all that said, and based upon what I've read, sounds like I need to clean my ICV or DISA (not even sure what a DISA is). It doesn't look that hard to do...question is, will this actually fix the problem. At first it was an annoyance, but if that was to happen in an emergency and you lose power steering like that, could be very bad. I want to fix this.

Thoughts are appreciated. I will clean the ICV soon, can anyone tell me more about this DISA thing?

Thanks in advance,
NicB.
 

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in an "emergency" situation like you described, all you had to do was slip the tranny into a relatively high gear (depending on how fast you are going) and pop start the car. :idea:
 

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Discussion Starter · #5 ·
^^yea, i guess i could have popped the clutch, but don't really like doing that. It's not VANOS, I replaced the seals a couple weeks ago. I was hoping it might address that, but it did not (not surprised though). I also don't think it is MAF related. I just put in a short ram K&N a while back and checked the MAF out, looked clean as a whistle. I'll try the ICV cleaning soon and maybe that will do the trick.
 

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^^yea, i guess i could have popped the clutch, but don't really like doing that. It's not VANOS, I replaced the seals a couple weeks ago. I was hoping it might address that, but it did not (not surprised though). I also don't think it is MAF related. I just put in a short ram K&N a while back and checked the MAF out, looked clean as a whistle. I'll try the ICV cleaning soon and maybe that will do the trick.
Did you start having this problem before or after the K&N short ram? If it started stalling after the K&N, switch back to the stock intake box and see if that fixes your problem. This is also far easier than cleaning your ICV.

Also, the fact that the MAF looks clean means nothing with respect to whether it's functioning properly. Now if it were coated with oil, you could certainly say it might not be fully functional but the reverse is not true.
 

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Discussion Starter · #7 ·
^^no, this problem has been occuring since I bought the car. Honestly, taking the ICV out looks easier than uninstalling the intake anyway. I have 106,000 miles on the car, I can almost guarantee it's dirty. I can spray the MAF down too with some electrical cleaner. Think that might help?
 

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I asssume you checked for codes and there aren't any? There are special cleaners for MAFs. Can also be cam position sensors or even crank position sensor. Check real good for vac leaks.
 

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When the engine speed decreases from revved to idle, the butterfly valve closes and the ICV opens. If the ICV sticks closed, then the engine doesn't get any air, and stalls.

Sometimes - very rarely - it will throw a code that says "Idle air control valve mechanically stuck" or something like that. But usually when it sticks, you stall out before you get the code.


Good luck with the hose clamps on the intake boots. They can be a hassle. A flexible screwdriver will make a world of difference. While you're in there, thoroughly inspect the intake boots for damage, cracks, or leaks.
 

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Discussion Starter · #10 ·
^^air leaks are out of question...I replaced the intake elbow a last year ago and just installed the short ram, so know the intake system is in good shape. I also had this problem long before I installed it.

MAF maybe, but unlikely, no code, problem only occurs when hot, which if it was MAF, I'd think it would occur whenever. camshaft position sensor already replaced, doubt its that. My engine runs beautifully.

I really think it is just a sticky ICV, which manifests itself in hot, humid weather. I might even play around with that tonight to try and clean it out.

Will let you guys know how I make out.
 

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Discussion Starter · #11 ·
Hi guys, okay so I took the beast apart today. The ICV was a tougher job than I thought mainly because of lack of maneuvering room. That said, I put it all back together. Idle is nice and consistent around 650-700 rpm. No more fluctuations when i drop to idle from high RPM.

That said, it seems to me like my intake is louder than before. I do have a short ram, but I dunno, sounds like there might be an air leak somewhere. Any idea where that could be? I mean, maybe it is from the ICV being cleaned or something, but I dunno, I'm nervous I have a leak somewhere. The only place that it could really be is the intake boot on the small connector that goes into the ICV. The part is new, so its not that it is ripped, I'm just wondering if I misconnected (although thought I had it right). I guess I can take it apart again.

Any other place it could be? Surely there wouldn't be an air leak between the ICV and throttle body, right? I locked that in and screwed everything back together, really no room for error there, I don't think anyway.

Maybe this is all my imagination, but the intake definitely seems to have more whoosh than it did before. Any thoughts are appreciated.

Thanks!
NicB.
 

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Discussion Starter · #12 · (Edited)
^^Edit: The weird RPM drop to idle is better, but not gone. I did another test. I revved to 1000 rpm and cut off, there was a pronounced dip down to 450 rpm then fluctuation back and forth until it "resettled" at 650-700. This is confusing. I'm reading the DISA may be playing a part, but not sure. DISA looked fine when i had it out. I'm going to take it back out and look it over / clean it more closely. I heard that if you turn the car to the on position, it should close the DISA. At least that way I can tell if it is working.

what else could this be? It is annoying more than anything, but I like stuff working correctly!

EDIT AGAIN: took disa out, connected, turned car to on, no movement, remains open...are we sure this is supposed to actuate closed? this could be culprit if so.
 

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Discussion Starter · #13 ·
Okay, sorry for 3 posts in a row, but I've been tinkering today...and this will likely help someone someday.

So I took the DISA back out like stated above, plugged in connector, turned car to on position but nothing actuated. SO, before I jumped to conclusions, I had another idea, why not put it back together and record the DISA arm in motion.

Sure enough, started recording with car turned on, and turned car off, the little arm that goes to the rubber vacuum thingy moved. Turned car back on, actuator moves (to closed position). So I figure, why not rev up to high range, actuator should open again, sure enough, rev to 4000 rpm, actuator opens up to default position.

I have this on video if anyone wants to see it.

SO, all this said, i rechecked all my connections and clamps, didn't see any air leaks, might try some carb cleaner in a moment or two. Fired her up, guess the sucking noise is just the intake and I'm just paranoid. Ah well, she is my baby after all. Anyway, the car is running pretty smooth. I'm still going to keep an eye on the idle fluctuations. It's difficult to duplicate, but if I learn anything more, I'll let you know.

If you ever need the video, PM me.

NicB.
 

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My car does this too and has been doing it for a few years now. I have the same car as yours. It is sporadic...but occurs more in the summer months...I think because of the extra load of the AC. I have seen it in the non-summer/non-AC months as well, but it goes to the point of actually stalling more in the summer months. Although here lately it hasn't been doing it that much and in weather(100 degrees) you think it would...not even the bouncy idle...go figure.

It didn't do this originally and I bought the car brand new. Everything else I have read people have ruled out...ICV, MAF, vacuum leak, etc. I think it came down to having your DME updated with the latest software. I had thought it might be the VANOS, but you already replaced your seals. I guess it is the software???
 

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Discussion Starter · #15 ·
^^Yea, I dunno bro. If it is a software update though, why did it not do it when you first bought it? :dunno:

I have ruled out VANOS, ICV, DISA, intake elbox, intake, vacuum leak, throttle cable position, etc. I don't really care most of the time, but if it ever stalls at a bad time, that could be dangerous.
 

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I have the same issue... I cleaned ICV, changed intake boots, put the oring on the disa (was missing), cleaned the MAF, changed the CVV (oil separator), changed vanos seals, changed fuel filter....still the same issue with idle. I will do the seafoam and deep creep cleaning in few days, hope it will help...other than that...DME update?
 

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I think there is a TSB(technical service bulletin) out about this...I think I have seen it on here before. It requires updating the DME. I think the dealer charges an hour labor to do this even though it doesn't take that long. So whatever your dealer's hourly rate is is what I would expect it to cost, but I could be wrong.

My car has a Dinan intake with software. I don't remember my car having this problem when I was stock. Although I don't remember it doing this until years after I had the intake...who knows. I guess if there is somebody with this problem and NO aftermarket intake that rules out the intake as being the possible culprit.
 

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NicB my first thought was a DME upgrade. My 330 does this on a really rare occasion so I don't worry about it. Anyways I'll be glad to look it up on AllData for you tonight or tomorrow. If I forget PM me just to remind me. I think I read this solution somewhere.
 

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mine would hunt around for idle after exitting the freeway. and at times, it would stall. took it to the dealer. they reprogrammed it and i have seen no further sign of this behavior and it has been 10k miles or more.
 
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