need help with thermostat on '98 century

[stony1313]

I have a 98 buick century and I think the problem I'm haveing is the the thermostat. I would only have heat in the car when I have driven it for a while. The tempeture gauge is jumpy too, it gets higher and then lower and depending on where the tempeture is at is how much heat I get in the car, sometimes freezing cold air. I had the same problem with another car, and it was the termostat. could someone please help me determine the problem and locate the thermostat, and how to change it, do I need to drain the coolant and do I need to mess with the exhaust pipe to get to the thermostat?

Thank you,

Stony

[tman]

Thermostat may not be the problem, but changing the thermostat is very easy. First, locate your upper radiator hose. look on the engine side, do you see two bolts around where the hose goes in? take those out. you will most likely have coolant leakage, so be ready to wipe up a few pints of coolant. next, your thermostat will come out easily, and remove the old gasket. Clean mating surfaces. Insert new gasket, and new thermostat, replace the bracket, and bolts, start the car, let it warm up, watching your temp guage, and topping off the coolant overflow tank.

[Ronnie R]

Originally Posted by tman2093

Thermostat may not be the problem, but changing the thermostat is very easy. First, locate your upper radiator hose. look on the engine side, do you see two bolts around where the hose goes in? take those out. you will most likely have coolant leakage, so be ready to wipe up a few pints of coolant. next, your thermostat will come out easily, and remove the old gasket. Clean mating surfaces. Insert new gasket, and new thermostat, replace the bracket, and bolts, start the car, let it warm up, watching your temp guage, and topping off the coolant overflow tank.

I have a 98 Century also and it's doing the same thing but you only get warm air out of the heater if the engine RPM is high. If you let the car idle it will over heat but if you bring the RPM up it cools back down. Never seen this one before, if it's not the thermostat then could it be the pump???