So I recently had the valve covers replaced but they put the left side gasket on wrong first time. Came back and put it on “right” but the car was smoking due to it burning off exhaust manifold so later on the car started to drive rough losing power in throttle and even stalled. Put it in run position where it said hot then I let it cool off and I heard a knock got home check oil oil was still topped off but the first coil pack had oil circled around it on top of the valve cover. Then the next day turned on blue smoke was coming out still followed by the knock I think the spark plugs drenched in oil any ideas. They came back the next day and said “they only can help me find a new motor” but I don’t believe it’s the motor cause it was running perfect


I think the smoke under the hood would make the temperature hand go up because when it would go away car would drive right. I turned car off everytime before it even went up
ideas ?

 

I'd pull and inspect the plugs to make sure they're not just loose, a loose plug can make some interesting sounds.

Also sounds like you need a different mechanic.