I have the given engine. My Grand Prix has been acting weird. Getting hot and only once overheating. I noticed when I have it running the coolant in the reservoir bubbles. Even if it has been running long enough to get the air out of the cooling lines. The hoses are stiff (I imagine this is normal due to the pump). It isn't violent bubbles but they are rapid. When I first start the engine it is light then it gets worse when I drive it. I don't think it is the head gasket due to the fact I don't overheat and that I don't have smoke or steam coming out the exhaust.