Odd smell from vents with AC off
When I turn the fan on with the AC off, the air coming through the vents has an unpleasant smell. It doesn't strike me as a chemical odor, nor does it smell like burnt oil (I know that valve cover leaks can sometimes cause a burning oil smell in the cabin, but that's not what this smells like).
To be frank, the odor calls to mind a neglected public restroom where people have been pissing on the floor. Switching between fresh air, recirculate, and auto-recirculate doesn't seem to have any affect on the smell. However, if I turn the AC on, the smell stops completely.
The dealer changed the cabin filter just a few weeks ago, but the smell is still there.
2009 128i | Alpine White | Terracotta Boston Leather | Premium Package | Steptronic