2003 Chevy Trailblazer The smell of nailpolish/acetone

Smells problem
2003 Chevy Trailblazer All Wheel Drive Automatic 64,000 miles

I'm getting the smell of nap polish/acetone through my vents. I only notice this when I am going under 30mph and it's the vent on. I don't smell it when the AC or recuirlating air is on. I've checked the floor board on passeger side and no leak there, no leaking under car. My husband thought he heard a light rattle and thought maybe the bearing in the water pump- could that cause the smell?