My 2000 Grand Prix GT is spewing the beautiful scent of exhaust fumes into my car (I think that's what the smell is) when I turn on the heater. As it's getting cold again, I just started the heater for the first time recently. The fumes happened right away, and keeps happening. I'm unsure if it's an exhaust leak that's being drawn into the car (the fumes dimish when I turn on recirc HVAC), or if there is a heater core issue, or both. I also notice that on the inside of my windshield, bottom of glass, there is a residew that looks greasy, as though its been "sprayed" up onto the windshield from the vents in the dash. Knowledgeable advice?
