Bad valve guide seals or worse?
I just took delivery of a BMW Certified Pre-Owned '07 328 Coupe last week. This weekend I noticed that after sitting for more than a couple hours the car will spew a pretty nasty cloud of white and blue smoke upon start up. I'm certain this is not just condensation. It's occurred with ambient air temps at 80+. The car seems to run a little rough at cold idle. Seems to misfire when cold. The oil sensor says oil level is at 4/5th. There are no faults indicated on the dash. It actually just passed smog certification today. I observed it during the test. There was no visible smoke of any kind when it was on the rollers. The blue smoke at start up makes me think that maybe the valve guide seals are bad. I have no idea why there would be white smoke with it. Maybe bad head gasket? I have made an appointment with the local dealership. This is a-little frustrating for me knowing that this may cost me some time.