Exhaust smell in heater system

I have a 01 Grand Prix GTP and there is a smell coming out of the vents when the heater is on. It smells like exhaust. Any ideas what might be causing this?

Sure it could be an exhaust leak, but my guess is leaking valve cover gaskets. A guy with eyes is better than us shooting blonde, I mean blind.

I think what Waterboy means is that you probably have oil seeping out a valvecover gasket and onto a hot exhaust manifold, and the resultant fumes are wafting up through the ventwork through which your heater air is drawn.

I’d get it checked out, though. If it should be coming from a leaky exhaust joint you could be getting exhaust is the passenger cabin and that ain’t good. You and the blond might both fall asleep.

YUP I CONCUR…can be an exhaust leak under hood…getting sucked into the vents too…as they stated.

Does your exhaust sound Farty under the hood? You can put your hand near the front ex manifold to see if that joint is leaking…your luck it will be the rear head near the firewall…fun fun fun