Couple of things you want to do: Open the oil cap, and - with the engine running - put your hand over the crankcase and cover the hole. You should feel a little bit of suction. If you don't ... you have a problem on the horizon. Turn on the A/C, and see if the car overheats. Open the radiator, see if the coolant has any debris. Smell the exhaust, see if it smells like antifreeze.