try a radiator cap......or you have a head gasket leak.
check the heater core stopped up radiator
did you check the radiator or the head gasket?
check your fan clutch if its weak it will overheat
Try taking the thermostat out completely, then see if it still overheats. If so, your only other problem has to be a bubble in the system and it needs to be burped. Took me about an hour to get a stubborn air bubble out!
replace upper radiator hose and install a new thermostat. see what happens. or turn it on without the thermostat for a while and see if it still overheats.
Check the thermostat to see if it was installed correctly. They can get put in backwards.
I would be thinking it is a head gasket.
dose the electric fan run if not check the relay if it runs check the water pump
Check the timing.
Check that the coolant fans are still working, then check out the water pump.
Check if the thermostat is working properly. See if the top of the radiator is very hot when the motor starts to overheat, if it isn't hot then chuck out the thermostat or better still replace it.
Generally, if your car overheats with the proper level of antifreeze, either your water pump has gone bad (not circulating fluid), the thermostat is stuck, or your radiator is clogged up inside. -NAPAman