2002 325is Idle Surge and Oil Consumption
My brother's 2002 325is with approximately 190,000km has an occasional idle surge during which the idle will oscillate up and down more and more until the vehicle stalls or until you push the gas. It doesn't do this all the time and from what he's told me it is usually when he's slowing to a stop but I've experienced it just moving the car out of the driveway. Last summer we did the usual ICV cleaning (it was already pretty clean), checked for vacuum leaks, etc. but didn't find anything.
His car also consumes quite a bit of oil. I'd say probably around 1L/1000km. I'm not sure what the common causes of oil consumption are on an e46 so I haven't looked into it for him (although I like to brag that my 1999 323is with similar mileage idles fine and burns no oil at all haha).
Any suggestions on troubleshooting the surging idle? And are there any common, repairable reasons for oil consumption?