M50B25 idle problem - BMW Forum

Krotes · 11-13-2012, 12:32 AM

I've had this problem since I bought the car. When I start the car cold it runs idle pretty well and stable and doesn't smoke, but after few minutes rpm goes down a bit and it starts running so bad that the whole car is shaking and it's smoking quite a lot too...so it seems to start running on rich for some reason? So far I've changed new bosch lambda, new sparkplugs, new camshaft position sensor, checked all intake hoses for any cracks and leaks, cleaned icv and tested that it's working and also tested ignition. Still no any diffirence. Got any ideas what to do next?

ElTonyo69 · 11-15-2012, 10:55 PM

I had a very rich and rough idle ad my problem ended up being the VANOS not being adjusted correctly.

Krotes · 11-16-2012, 01:38 PM

Quote:

Originally Posted by ElTonyo69

I had a very rich and rough idle ad my problem ended up being the VANOS not being adjusted correctly.

I got non-vanos, so can't be that.

Ivan413 · 11-18-2012, 07:26 PM

My e36 had an idle problem. If you haven't cleaned your MAF sensor, so and if problem continues its most likely you o2 sensor causing the problem

Lord Vader · 11-23-2012, 08:18 PM

Quote:

Originally Posted by Ivan413

My e36 had an idle problem. If you haven't cleaned your MAF sensor, so and if problem continues its most likely you o2 sensor causing the problem

Bingo. This is most likley the problem. A bad O2 sensor can cause a host of issues as the car doesnt know what the air fuel mixture is and cant adjust properly. Bad idling and running rich is quite common.