Rough idle on start

[Smokin]

Seems to happen for only about 10-15 seconds on first start of morning until idle speed slows a bit. Sometimes even sounds like I'm revving the engine. Just took her in for Inspection 1 and they couldn't find anything (no codes). They speculate "fuel" except that I try to only run Shell V power in her. Anything else it could be? What are symptoms of VANOS? Valvetronic? DISA? Got 10k more miles on new car warranty so I'm not sweating, just would like to find out what causes it.

 

[normski]

Mine does the same. As far as I know, from what I've been told by others on here. It's the car getting the cat up to operating temperature, so that it meets emission standards.

I imagine many others have the very same revving on warm up.

 

[Smokin]

My service adviser isn't concerned and it runs fine otherwise and it's not throwing a code. Talked to another adviser when I dropped it off (mine had gone home) and he says so far, the N52 engine is proving to be pretty bullet-proof. I hope that continues.