If you replaced the head gaskets, thermostat, and the water pump and it is still overheating then I would ask about the fan. If it is not the fan, then I would say that you have at least one bad head, if not two. But that is just a guess. A mechanic will pressure test the system and will be able to tell you more. Is the radiator restricted?
One of the major causes of a car overheating is a leak in the cooling system. Other causes are a clogged radiator, a bad thermostat, a broken or split hose, a worn out water pump, and a faulty cooling fan.
check for a stuck thermostat. to do this simply squeeze your air in take line once your engine has warmed up and if it had pressure your thermostat is OK Check the fluid in your radiator to see if there is enough and if it is still in good condition,
The hose that goes in the top of the engine, the thermostat is in the hose.Unscrew the hose take the thermostat out and replace,Very easy
Drain the radiator. Remove the top radiator hose on the 2003 Buick Century. Unbolt the hose inlet. Remove the inlet housing and take out the thermostat. Replace the thermostat, install the housing and top hose, and refill with antifreeze.
The thermostat is located in the top radiator hose connector. The top hose and the housing need to be removed for access.
CHECK YOUR THERMOSTAT.... AND GOOD LUCK
The thermostat is located in the top radiator hose connector. The top hose and the housing need to be removed for access.
inside the radiator hose
If you need to replace the thermostat, you need 2-3 hours because in order to reach it you have to disassemble few other components (like MAF hosing, air filter housing). Send me a valid e-mail address and I can reply to you with a set of pictures I took when I replaced my thermostat.
thermostat temp degree
Follow the top radiator hose back to the engine. The thermostat is behind the housing that connects the top hose to the engine block.
Follow the upper radiator hose to the engine. It is clamped onto the thermostat cover. There should be a coolant bleed screw just above it. 3.1L engine.