Cooling System Bleed Procedure 2002 Honda Accord EX


If my heat gauge is reading all the way hot but motor and coolant is only warm to the touch and no smoking or boiling over would it be the thermostat?

Probably Not. The heat gauge uses a ECT Sensor to indicate the engine coolant temperature. Sometimes if there is an air pocket the sending unit will read hot until the cooling system is properly bled. Once the system is properly bled you can use an infrared hand held temperature gun to check the accuracy of the gauge.

The first thing I would check would be the coolant level. Also confirm the temperature gauge sending unit wire is connected. If it has become disconnected it will read full hot all the time with Key in ON position.

If you just worked on it and are now having the issue, check around the area you were working to make sure you didn’t accidentally leave a wire disconnected.

You can check the the sensor by removing it and using checking the resistance ohms.

Application Resistance (Min-Max) Ohms Temp ºF (ºC)
EX 15000 – 20000 -4ºF (-20ºC)
5000 – 7000 32ºF (0ºC)
2000 – 4000 68ºF (20ºC)
900 – 1200 104ºF (40ºC)
300 – 400 176ºF (80ºC)
100 – 300 248ºF (115ºC)
Engine Coolant Temperature Sensor Location

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