the car was overheating and I changed the thermostart and the waterpump but it still overheats...what more can I try?

 

You started with the right things. But it could be the head gasket leaking.

Look for evidence of a leaking head gasket. Look at your coolant. Is it full? Is it contaminated with oil? Look at your oil. Is it contaminated with oil?

 

Hello, Do a compression test as well as the stuff VTBricked mentioned; it's easy and fast. Does your car overheat as a progressive warm up-suggesting a plugged radiator? Does it overheat in slow or stopped traffic-suggesting a inoperative fan? If the temp is rising will a run onto an open highway bring the temp down-suggesting an inoperative fan? Your car is old enough to have a failed coolant temperature sensor as well. I do not know how they tend to fail (read high or low or just die). Kira

 

Filling the system with antifreeze the normal way after waterpump or related repairs is difficult. Air gets traped.I took the rad hose off and filled it from there. It works