guys i took off my radiator, fan, alternator,belts,and im about to take off the water pump. The reason is that there is oil buiding up on top of the water pump, than on the left side of the water pump there is coolant residue dripping down.....i dont know if it is the gasket....leaking oil.....or the pump is bad.... the plan is to just replace the thermastat, and replace the gasket.....b/c the car is overheating (according to the gauge) than it cools down...than gets hot..than cools down..but never cools back down to where it normally is....sound like a faulty thermastat or could it be due to the leak????? im lost...