My gl runs at 180 degrees all day long in any conditions as long as it is moving. however, at a long red light or stop and go traffic it starts to slowly overheat.

 

the fan works anytime I want it to as I have a manual switch. this slows the overheating but doesn't stop it. I flushed the radiator. I cleaned the exterior of all debris. I put a new radiator cap on. I change the oil every 3 k miles. the timing is right on the money.

 

what else can I do?

T-stat?

ya. will have to check t-stat. thanks. I think I put a new one in a couple years ago but should check anyway.

Also, there could be some air in the cooling system.

The best way to fill it is to pull the front end of the car on to something so the nose is up in the air. You want the car to be at an angle.

Then fill it up as much as possible with it not running. Start it up with the cap off, keep filling and keep burping the air out by squeezing the pass side hose. wait for it to get up to temp and if it starts to push back out you should be able to pull the throttle open a bit and that should lower the coolant level enough for you to put the cap on. Once you have the cap on, add some more coolant to the resevoir.