Thermostat: Testing and Inspection
DIAGNOSIS AND TESTINGTHERMOSTAT
1. Remove the thermostat from the engine.
2. Suspend the thermostat in a container of water.
CAUTION: Never use a welding torch or soldering torch as the sudden introduction of heat alters the structure of the metal!
3. Heat the container and thermostat.
Note: The rate of increase should not be more than 1°C to 2°C/min from about 8°C below the start of opening of the coolant thermostat.
4. Measure the temperature of the water.
5. Heat the water to the temperature specified on the thermostat. Allow the thermostat to fully open, and then measure the distance of the stroke.
6. If the specifications are not achieved, install a new coolant thermostat.