I bought a 98 cavalier and when i bought it the motor was completely quiet. Now the other day I went out and started it up and it is knocking. It is only on startup, if it runs awhile it goes away. What would cause this? It is a 98 2.2 automatic...Please let me know if anyone knows anything at all...

Garrett, the dealer or previous owner may have

"doped" the engine....by that, put some oil thickener

in the crankcase in order to disguise something

like bad main bearings. I've even found sawdust

added to the engine oil to do this.

Anyway, if the noise began immediately after you

changed the engine oil, this is what I suspect.

(An experienced mechanic can take the car

overnight, let it sit until the next morning, then

give an educated opinion of what he hears.)