4.8iS N62 smoke only on idle...
 

Hey guys,

I know this has been beat to death, I know, but searching didn't get my specific issue addressed. Bought my car with a valve seals done by a BMW tech in Jersey and replaced with BMW valve seals. When I purchased it, the owner said it has always smoked, even after this service, but only after letting it idle for about 5 minutes.

This has been totally true. It doesn't smoke at ALL until I let it sit for 5 minutes or so, then it billows blue smoke. After a good blip of the throttle or driving off, the car completely stops smoking again.

I replaced both PCV diaphragms, but while doing it, the right bank diaphragm had some yellow goo on it. Had it been anywhere else, I'd say it was coolant mixing in. It was only in that spot-- the rest of the oil looks fine, and there's no oil in the coolant.

https://live.staticflickr.com/65535/...48e5be1a_b.jpg

Any thoughts on this? I'm happy saving up for another valve seal service with the upgraded seals, but is there somewhere else I should look? Is it odd that it ONLY happens at idle and after idling for a while???

Bump

Idle and decel is when the engine has the most vacuum which is when the valve stem seals rear their ugly heads unfortunately.

Mine had it too when idling for 10 min in traffic or at the boat launch ramps.

I started using liquimoly 10w60 oil and it helped for now.. no more smoke but I know I'm on borrowed time with the seals.

How long ago were the seals done? How many miles on it? Mine were done around 120K miles and the problem disappeared after the job.