I got a major problem. i have a 2002 grand prix se, love the car but havin major problems with the engine. in december i got the head gaskets and all the gaskets up from that changed cause of very overheating and no coolant, i am still over heating and not getting heat in the vehicle, i was told and thought it was the thermastat, water pump, coolant change, changed all of those didnt do anything, cause when i got the head gaskets changed i flushed and put in prestone all makes, models, green coolant. didnt do none, so now i got to thins left radiator or head gaskets again. things i notice..... The upper radiator hose is very hot but the lower is cool, the two heater core lines the one flowing in is hot the one comin out is cool also.... when i first start the vehicle it has a little white smoke out the exhaust then goes away. i need help someone please give some info thanks