Nissan Repair: Thermostat problem ?, nissan sentra, fuse box

Question
Hi, I recently replaced the radiator top hose on my Nissan Sentra '97, It was causing water lose and overheating. Everything went fine for a wile but now my thermostat gauge goes from a normal position to just under the red mark, stays there for a few seconds and then goes back to normal. It does this a few times on any given journey. Is the thermostat faulty?

Answer
Hi Charles

Although the thermostat is probably your culprit, there are other components that might give you an overheating issue.

Run the car to operating temperature. Feel the top hose and the lower hose. If the lower hose is cool, and upper hose is hot, then the thermostat is stuck, and you should replace it.

If both hoses are hot, then check the operation of the cooling fan, has to go on when the engine is at operating temp, or the A/C is turned on.

If the fan is not working, then check power to the fan terminal. If there is power, then replace the fan motor.

If no power, then check the fan switch, or fan relay. The switch is usually located on the radiator, and relay is in the large circuit fuse box next to the battery.

Hope this helps -
aloha
calvin