I have changed the water pump,thermat,radiator, just have no more ideas do you

It's entirely possible that you have a failed head gasket.

A little more info about the car, ie: model and engine, mileage, etc. And some more clues about the symptoms, please...

Ensure that the electric cooling fan works properly and that the thermostat was installed correctly.

2001 olds 3.5 v6
I truely don't think its a head gasket becurse it runs like a champ and there no white smoke, and plus it will sat and run for ever without getting hot, the only time it gets hot is when yours going down the road, so i kind of think it just has air in it but i have try everything to get the air out, so do you have any other ideas
Purging air from any car's cooling system is critical to overall system performance. Txgrease has a very good point about the cooling fans. Further diagnosis is crucial... then we can get to finding out what's wrong!
Let us know.