overheating 98 mercury sable gs

my 98 mercury sable gs is overheating when im sitting at a red light. it immediately goes back down when i start moving. i flushed the radiator and it did no good. my fans work. the car has 121k miles. do i need a new radiator, a thermostat or what? please help

my 98 mercury sable gs is overheating when im sitting at a red light. it immediately goes back down when i start moving. i flushed the radiator and it did no good. my fans work. the car has 121k miles. do i need a new radiator, a thermostat or what? please help

Check the Cooling Fan. It may not be working and is probably electric i.e. not belt driven.