I have oil vapor smell inside my 850 when idling or driving slow. At speed not so much and with the air on not at all. I have replaced the oil filler cap seal and I don't see a leak anywhere. Any suggestions? Thanks for your help! This is my first Volvo so I don't know much about the car yet.

 

I had the same problem with mine. Is it a turbo? If it is check the seal that goes from the bottom oil line from the turbo to the block. There is an O ring in there that deteriorates and can leak from there. Then, follow that same line up to the turbo and there is a flange gasket where it bolts on. See if it is lraking there. If they are leaking it will blow oil back onto your cat and exhaust. When was the PCV system changed last?

 

Most likely a clogged PCV system

 

Or a hose broken.

 

Good point!