Thermostat check

1. Remove the thermostat from the car.

2. Immerse the thermostat and control thermometer in a glass container with coolant so that they do not touch the bottom and walls of the vessel (this can lead to misrepresentation).

3. Place a container on the hotplate and increase the temperature of the coolant while watching the thermometer reading and thermostat valve movement. It should begin to open at a liquid temperature of approximately 88°C and fully open at 92°C.

4. Replace the thermostat if it fails at least one of the test requirements.