Exhaust Smell When Idling

[R2+2]

Hello,

This one has stumped me and I'm hoping someone can help. I have 2002 Sunfire 2.2. When we were stopped at the lights we could smell exhaust in the cabin, though it was the car in the next lane but it wasn't ? This happens fairly regular, if you have any of the cabin air climate controls on you can smell exhaust in the cabin while idling but not when your moving. If you have the controls off, no smell.

I suspecting a vaccum control for the heater flapper, is that a possiblity ?

Thanks in advance for your help.

Take Care
Roy

[R2+2]

Good Morning,



FYI, I continued to hunt for the smell. My son pointed out that the oil filler cap was loose and raddling around, I didn't think anything of it at the time, but yesterday when the air was still and cold, I started the car and noticed that crankcase was venting out through the oil filler. Obviously this is unusal and after futher investigation the PCV valve was clogged. The smell in the cabin was he crankcase venting out though the oil filler, drifting up the inside of the hood (because of the curved hood) right into the outside cabin air intake vents infront of the windshield. I fixed up the PCV and all is good again.



Take Care

Roy