Hello everyone! My name is Cutter! I purchased my first Mini Cooper as of this month! It's a 2009 base N12.

I love driving it so far, however it has a issue I am stumped on. Trust me when I say I've read 90% of related threads regarding my issue. None quite match mine. ha!

On cold starts (or barely warm after sitting for a few hours), I have a rough idle surging between 600-1200rpm while stuttering/cutting out lightly. This is accompanied by a kg/h of 30-40 reading of the MAF (note: once the car is warm and not rough, the same RPM idle has a kg/h of 9-12). I have replaced plugs and coils as they were pas their service interval along with trying a MAF, cleaning the throttle body and fuel injector cleaner. None of them have helped. I hear a whistle that changes with RPM--I have removed the oil cap and it continues.

The other concern I have which I would assume is connected is during driving at all speeds, tip in and tip out throttle is very jerky and stuttery. I have no clues as to this.

Any help would be appreciated!

If this is posted in the wrong area, please forgive me--I'm new to this forum!

 

Update: pulled both VANOS solenoids and cam sensors and cleaned them—the intake solenoid did have some particles on the screens however once put back in and started, the rough idle was still present. Any other ideas?

 

CVV (PCV) membrane? I've been reading quite a bit about these, and think I saw that if they're torn, you hear a 'hiss', which would be at/near the back/left of the valve cover (when standing in front of car, looking an engine bay). I've read that the 'official' Mini/BMW procedure would have you replace the valve cover assembly, as the membrane is somewhat integral to it. But I just ordered the Russian aftermarket repair kit for ~$45 on eBay (mentioned in several other threads here). For me, I'm hoping to address the blurpy idle on my 2010 R55 N12 base clubman (with 38k miles). In my case, the symptom is quite minor, but can feel occasionally like a small/minor misfire, only at idle. Your symptom perhaps could be a more extreme failure of the membrane? Just guessin'.