How should the oil cap act with a good/bad AOS?

[Dale_K]

Originally Posted by jcb986

On a good AOS, you can loosen the oil cap and lift it up. On a bad one, like mine, I couldn't even loosen the cap. Also, if it's a total failure you will get lots of blue smoke. With lot's of oil moving into the combustion chamber you could damage the engine. When mine failed, the engine had a loud screeching like a belt tensioner going out when the engine warmed up. It was pulling air through the front crank seal.

Thanks for the informative reply (I've been searching AOS info on several sites). The second reason I think there might be an AOS problem is that the car has a stinky smell that I think is crankcase fumes (sort of smells like a pickup truck with a blown motor). The smell is most noticable near the rear fender vent on the passenger side.