Oldsmobile/Buick Repair: Engine Overheating, buick skylark, radiator cap

Question
Hi Pete,
I have A 1994 Buick Skylark, 2.3L overhead cam.
Mileage;150,000. The car constantly overheats after it's run 30 minutes. It does not lose coolant, however.
I installed a new thermostat and water pump but it still overheats.
It seems as if there is air in the radiator when I removed the radiator cap. I believe there is air in the system. Is there a way the air can be removed? If so, how? Is there a valve on the engine that I can let the air out and if so where is it located?
Thanks for your help.  

Answer
hello james
the only thing you can do is start the car up when it is cold and then take the rad cap off to you see the collint comeing out of the rad then hit the gas and refill the rad this is called burping the system .

it also could be a head gasket if burping does not work have it checked pete