I have a 1997 Honda Accord with 158,000 miles. My temperature guage fluctuates. It warms up after 5 minutes to 3/4 between cold and the center line. After 10 minutes it will go to center line and then 1/2 between center to red. At this point it will go back to center and below center. It will then repeat itself. When I turn off the engine, the engine fan comes on. It has never gone to red.
In August 2007, the radiator, thermostat, and hoses were replaced. In August 2002 the timing belt and water pump were replaced.
Any idea what could be causing this problem?
Check the level of coolant in the radiator and make sure there are no air pockets in the cooling system. If you Accord is a 4-cylinder there is a bleed valve on the engine to allow air to escape when the radiator is being filled.
I’d think about having the ACTUAL temperature of the engine determined and have the temperature sender tested. If the sender is faulty or there is a poor electrical connection it could cause incorrect gauge readings.
The cooling fan is controlled by a separate temperature sender in the radiator. This sender, too, can be tested to see if it’s working correctly.