My car has been burning oil for over a year. there is no leak. I have been putting three quarts in every 4 to 6 weeks. I have now replaced two coil packs and the spark plugs. my engine light is on because it said 3 and 4 was misfiring so i recently replaced those coil packs and now it said spark plug and i replaced it again as well. so the engine light coming on and what it says the problem is is wrong. now when i push the gas it is knocking or missing. not sure how to describe it. no one has looked at it other than a friend that is a mechanic and he says its probably the engine because this kind of car has these problems.