I would take out radiator thermastat test it by putting it in boiling water if doesnt open it froze replace the thermostat u could check radiator by taking cap of make sure full water and it is warm not boilinghave someone step on gas to see if water flows fast when step on gas DO NOT DO IT WHEN BOILING OVER when warm the thermostat doesn,t open still reaches temp most cars have 195 degree thermostat it starts to open to allow flow of coolant