i am about to take my car into a shop , but i would like to get some insight into what be the cause of it doing this, its aways used a little oil but now every now and then i can be driving along and the check engine light would come on and the car would start smoking badly after pulling over and letting it run awhile it would stop smoking and after driving for awhile longer the check engine light wuold go out by the time i get home i would have put a quart of oil in the engine does anyone know what this could be before i take it in to get look at ?