Coming to a stop idle drop

Hey everyone, I've been doing lots of research on this and I was hoping others could share their experience/fix if they had similar idle issues.

I've been battling this issue for a while now and I thought I had it figured out when I cleaned my MAF, ICV and DISA four months back, but it has resurfaced again. While coming to a full stop my idle seems to dip to around 475-500 rpms as the car comes to a rest. The car sort of shakes slightly like it's about to stall, but it never does. The idle then quickly returns to its normal 550 rpm as though it's correcting itself. It happens maybe 50% of the time depending how I'm stopping .

There could be lots of reasons for this, but this is what I am doing immediately: 1)replacing intake boot; 2)replacing intake camshaft position sensor; and 3) fuel filter. A bit further down the road I will drain and replace tranny filter and replace DISA (I believe the gasket is shot).

My CEL/SES has never come on and the car runs great otherwise. No codes. 2001 Auto, 320Ci, 94K miles. As far as PM: cooling system overhaul, new belts, tensioners, PS pump, alternator and spark plugs.

Has anyone else experienced this? If so, have you fixed it and how? So far, I'm just hitting the normal wear and tear items so I don't mind doing it without knowing if it will fix my problem or not.

Thanks

I'm dealing with this same issue, except mine will stall sometimes. I've replaced both intake boots, CCV and hoses, vanos seals, VC gasket, spark plugs, fuel filter, cleaned MAF, throttle body, and the ICV.

I also "upgraded" my DISA valve with the G.A.S. kit, but I'm starting to wonder if I should just replace the unit all together.

No codes here either.

Originally Posted by LaCrosse540i6

I'm dealing with this same issue, except mine will stall sometimes. I've replaced both intake boots, CCV and hoses, vanos seals, VC gasket, spark plugs, fuel filter, cleaned MAF, throttle body, and the ICV.

I also "upgraded" my DISA valve with the G.A.S. kit, but I'm starting to wonder if I should just replace the unit all together.

No codes here either.

Have you changed the intake CPS yet? I can't remember were I read it, but I think it was on e46fanatics where the guy changed everything you did including the intake cps and it fixed it. Let me see if I can find that thread again. This is a pain in the A$$. Have you checked your vacuum hoses as well?

My car was stalling 20% of the time last year during the summer (if I didn't want it to stall I would have to apply more gas OR make sure it was always in gear) -- this was after replacing the MAF, intake boot, hoses vanos seals, VC gasket, spark plugs, fuel filter, CPS, oxygen sensors, blahah... blahha.. blahha . (yeah, it was frustating

However, after I fixed the rattling from the heat shield under my car the car is acting more civil -- I think the heat shield that was rattling like a can full of pebbles might have been affecting my exhaust system and causing the unstable RPM at idle. It was banging against the exhaust components and probably causing the sensors to read incorrectly. I could be wrong though. I've only fixed the rattle of my car a month or two ago -- but no stalls yet and it seems more stable :-)

Originally Posted by PerfectStorm01

Have you changed the intake CPS yet? I can't remember were I read it, but I think it was on e46fanatics where the guy changed everything you did including the intake cps and it fixed it. Let me see if I can find that thread again. This is a pain in the A$$. Have you checked your vacuum hoses as well?

I have not changed the CPS yet, but I suppose that's another one I should check off. I have replaced the SAP and FPR vacuum line.

eleison, that's an interesting idea you brought up. I suppose if something was rattling that could be picked up by the knock sensor.

Originally Posted by LaCrosse540i6

I have not changed the CPS yet, but I suppose that's another one I should check off. I have replaced the SAP and FPR vacuum line.

hey lacrosse, check out this thread from e46fanatics regarding another possible vacuum weak point.

http://forum.e46fanatics.com/showthread.php?t=921500

Ahh, so that's where that cap is. I had heard about that being a potential problem, but I never got around to checking it.

I'll probably regret saying this, but I really wish my car would just throw a code.

Originally Posted by LaCrosse540i6

Ahh, so that's where that cap is. I had heard about that being a potential problem, but I never got around to checking it.

I'll probably regret saying this, but I really wish my car would just throw a code.

I hear ya! I just added it to the list of things to check.

Post #5 http://forum.e46fanatics.com/showthread.php?t=885693

Looks like this guy has resolved a similar issue with a new CPS. I'll put that next on my list and report back.

Good luck! I'm still looking for a different post I saw regarding the same issue we have. I knew I should have subscribed to it back then...damn