I have a Nissan Sentra 1989 Model. E16 engine.
My car never used to overheat, the temperature gauge never even budged. I was OK with this as the car always drove well. a few months ago i noticed my temperature gauge starts rising then stays around the middle, which is normal. but whenever I stopped at a traffic light or in heavy traffic, the car would overheat, only for the temperature to fall again when I pick up speed. That happened for about 2 months until i blew my head gasket. I fixed the head gasket, flushed my cooling system then the car was back to normal as it first was, ie: temperature gauge not moving at all. which is the way i like it. But that only lasted 2 days, then it started overheating again. I flushed the system again, the car was then fine, the temperature gauge comes up to middle in the city, but goes back down when on the freeway. this lasted for about 3 days, today though, on my way to work, the temperature gauge just went all the way up to the H even on the freeway, but when i stopped at a traffic light the temperature came down just a little. I am not sure if it is the thermostat, water pump or fan. When I turn on the ignition, (car not started yet) then my fan goes on, so it cant be the fan. I am very confused, please help.