Hello Everyone,

I'm hoping someone has seen or know what this could be. My daughter's R60 Base is making this revving noise at idle, but the RPM/Tach is stable and normal level. No codes or lights! Checked with Schwaben Tool.
Any idea what to check or it could be?
Please check video sample of the issue to hear.

 

So I pulled out the 2 Vanos Solenoids this weekend (lost the bolt into the oblivion of the motor recesses in the rear intake one) and they looked pretty good and clean. I was expecting to see some clogging. Couldn't find anything. So I still actuated them with 12V while spraying with MAF cleaner and then air dry. Reinstalled them and only then decided to check the oil level and it was over 2 quarts low (this is daughters car) :-(. Toped up the oil and started. Car ran the same/rough idle for a few moments and then cleaned up and ran normal again. Not sure if the cleaning or having the oil topped up was the root cause... Happy it returned to normal (for now).