Originally Posted by Spyderturbo007
Is there a way to diagnose the exact cause of the rough idle? I'm experiencing the same issue with my 2006 330xi when at idle in Drive or Reverse. The issue doesn't occur when in Neutral or Park.
I've read that it can be a dirty MAS, plugs, wires, Vanos or the Valvetronic Sensor. Is there a way to nail down the culprit without a fault code? I had one of the Vanos replaced already before I bought the car because of it throwing a code.
I would have started my own thread, but I'm not allowed, so I figured that since this one was resolved, I wouldn't be hijacking.
sammk, I love your Kat. I have one too.
Video of issue:
Not sure how exactly to pinpoint. To add to your list of possible causes, I've read that some people had leaking PCV pipes or other hoses, leaking valve gasket, oil-soaked eccentric shaft sensor, oil change gone wrong - oil cap wasn't torqued down properly, or seals cracked/not replaced, or lower quality oil (my nearest bmw dealership uses cheap, non LL01 oil!).