I've had my 2002 Bonne for about 6 weeks now. We noticed a strange smell while sitting at a red light, driving into our garage, etc. We thought it was spilled oil on the engine but since buying the car we hoisted it up and power washed the bottom. We keep checking the oil to see if the oil level is low and it is not. It smells a little different than hot engine oil. The previous owner had just changed the oil before selling the car to us. He also had replaced the valve cover gaskets. There is nothing visable to explain the smell. It does not smell like antifreeze. There is no smoke. Anyone have any ideas?

There is the clue. If the gaskets were leaking onto the exhaust manifold, that would have caused smoking and a burned oil smell getting worse until he changed them. My guess is that the caked-on burned oil residue still has enough volatile matter remaining that you smell it when the car warms up. If so, and the leak has been stopped, the smell will eventually diminish and finally go away.

I know mine and a few others have or had leaking oil pan *, just seeping not losing much but sometimes I can smell it.