97 Sunfire - temp running high

[snowland67]

I have a 97 Sunfire that is running warm while driving in town. Needle is still in the normal zone, however in town it will creep up towards the higher end. There is no leaks from the raditator system, just replaced the waterpump as it was leaking. Could a bad thermostat cause this, and other ideas.

[GTP Dad]

Welcome to AF!

It is possible that this is a problem with the thermostat. It could also be due to trapped air in the engine. Air is a common issue with newer engines and can cause overheating issues. If you have a radiator cap rather than a pressure cap on the recovery bottle, simply leave the cap off and start the car until it gets warm and the thermostat opens. If the level drops then you have some air in the system. Simply top it off and reinstall the cap. Also if you change the thermostat use a failsafe stat that fails in the open position.

Finally, insure that your coolant is properly mixed 50/50 and that the fans are coming on. Either can cause overheating. And don't forget to clean the crud out of the radiator fins. This can cause issues too. Good Luck!

[snowland67]

thanks for the help. After doing some research these cars have a purge valve for the heating system, so going to try this weekend.