Omg the dealer is telling me the same thing. After I had a diagnostic test done a few weeks ago they told me it was the valve cover that caused the check engine light to come on. So on Saturday I had the valve cover replaced and ever since the car smells like burning plastic and so much white smoke coming from the tail pipe that it is shame. Take the car back and of course they rip me off a again by saying the engine is dirty and that they want to do another diagnostic test. This time they say the vacuum pump is leaking oil? I just don't understand why I smell burning plastic and don't smell oil. I really believe the dealer screwed up my car. Should be no reason why white smoke is coming from tail pipe. Sorry for my venting!