Be sure the thermostat is not installed backwards.
Overheating problems are caused by clogged radiator, non-functioning cooling fan, defective thermostat, defective water pump, defective or incorrect radiator cap, clogged water ports in engine, or collapsing radiator hose.
It could be the thermostat. Open up the radiator cap when it is hot and see if the water is flowing in the radiator. If it is not then it may be a thermostat.
Thermostat regulator is malfunctioning, water pump pulley could be bad, gas bubble in radiator hose.
check the heater core stopped up radiator
Blown head gasket?
Low coolant, inoperative radiator fan, failed water pump, restricted radiator, head gasket failed, stuck thermostat.
clogged radiator or bad water pump
You can find it inside of water outlet (there is a hose connecting the outlet and the radiator). You will have disassemble outlet if you want to gain access to the thermostat.
Be care-full my radiator blew up and burnt me. I replaced Radiator, thermostat, and water pump. Timing belt is in the way so I replaced it too. OK Now
did you check the radiator or the head gasket?
check your fan clutch if its weak it will overheat
did you try replaceing the thermostat or radiator or even check the hoses