On my toyota camry i was having overheating problems. I had the radiator replaced due to clogged, new relay, and thermostat, and cooling temp sensor. Now at idle the car overheats but gauge moves up n down also and when driving at low speeds. But at highway speeds the engine temp is fine. Could this be the indication of a bad thermostat or could my water pump need to be replaced. Been on for 95,000 miles. Belt has been replaced.