08 MCS rev's bouncing hi-low at startup
 

Hi, my 08 MCS manual is revving strange at startup. It does this 75% of the time. About 30seconds after I start it the engine starts to almost die and drop to low low rpm then bounce back and then fall and almost die again. It will do this for 15-45 seconds then it will run fine the rest of the ride. If I shut if off for even a minute and restart it the same thing will happen...The car has 54k miles on it and just before 50k I had the tensioner and spark plugs replaced under warranty.

Any suggestions?

Dan

Are you still in the warranty period? If so, head back and let the dealer handle such.
If not, grab hold of a MINI-approved scanner and see what current fault codes are present.

Could be as simple as the solenoid valve (SOLV) that's located on the back of the cylinder head.
But more testing and information is needed before making a critical decision.

- Erik

Out of warranty. Would the code-reader that autozone uses to check codes work. I'm sure it is a general one and not manufacturer specific.

That would get you started; a generic OBDII reader only gets you so far however...

- Erik

I read similar symtoms from M3 forum. When people tune their ECU, some tuner delete “cold start-up program” not sure why but seems like that was the problem. if you haven't tuned yours, it could be numerous things. hope this helps