Smoke coming from center interior vent

[dog2bert]

On occasion smoke comes from center interior vent for a couple of seconds and goes away.

What oil leak do you think would cause this?

I have already had the valve cover gasket replaced, but maybe it is leaking again.

[stephen]

Are you sure it's smoke and not moisture?

[cobra]

I've seen vapors come out, from the A/C system or whatever

[Cubieman]

Leaking heater core would produce coolant vapor, if smoke...where there's smoke there's fire, do you smell burnt wiring smell?

[K-Dawg]

My car has done this occasionally. Never any residue on the vents nor any odor, so it appears to be condensed water vapor.

[dog2bert]

It definitely smelled like oil

[FBloggs]

If oil odor, then may be cam cover gasket failure at the rear(cyl 6).
If no oil, it could be the final stage unit, aka hedgehog, failing.
you may also want to pull the shear plate and look for a leaking CPV on the block aroung cyl 6.

[Jimbo's M]

If oil odor, then may be cam cover gasket failure at the rear(cyl 6).
.

Concur. Had that, and the smell. You may try getting back there and re-torque the nut, if not all of them, and that still may not fix it.

[dog2bert]

Cam cover is different than the valve cover?

[FBloggs]

Same thing.

[sapote]

It definitely smelled like oil

Impossible unless the rubber seal around the cabin air filter is missing, or the rubber flap is missing on one of the rain drain tubes on both side of the cabin filter.

[heinzboehmer]

Impossible unless the rubber seal around the cabin air filter is missing, or the rubber flap is missing on one of the rain drain tubes on both side of the cabin filter.

Disagree. I've had oil smell come into the cabin before from a leaky valve cover gasket and with all the things you mention in place. The smoke goes around and finds its way in. Maybe through the top hood vent? Yes, there's also a filter for outside air, but it doesn't filter out absolutely everything, nor does it seal 100% perfectly.

[Jimbo's M]

Impossible unless the rubber seal around the cabin air filter is missing, or the rubber flap is missing on one of the rain drain tubes on both side of the cabin filter.

You don't think it's possible that burning oil fumes can't make it through the firewall? I know mine did, and it was exclusively when I was romping on it. Re torquing the valve covers nuts solved the issue for me.

[sapote]

You are right. I should have said impossible to see engine oil smoke through the fresh air vent. Smell, yes.

[sbay]

I once had a really bad oil smell coming through the vents and it turned out to be the valve cover gasket. I had just changed it a couple months back and the smell still appeared. Whether that was due to me using an OEM (not OE) valve cover gasket, or me not seating it right, the smell was still there. I then changed to an OE BMW Valve Cover Gasket and took my sweet time making sure everything was seated properly. No oil smell issues since. BMW VCGs last a long time too so you’ll make your money back in the long run.