1991 buick GS

[bartt]

I have A 1991 buick regal GS The other day while driving I went to clear the windows with heat using the defrost button and smoke came in through the vents,It doesn't happen with any other button,It was not electrical it was more like exhaust or oil smell, any help would be great thanks .

[bartt]

[heidigirl]

it didn't smell acrid, like an electrical short? i doubt that you would have been able to see exhaust fumes. it could very well have been vaporizing coolant. did it smell sweet?