- Remove the thermostat from the vehicle in order to perform the thermostat
test. Refer to
Engine Coolant Thermostat Replacement
.
- Fill a pan with a 50/50 mixture of ethylene
glycol and water.
Important: Do not place the thermostat (or thermometer) on the bottom of the pan. The
concentration of heat is uneven at the bottom of the pan. This condition may cause
inaccurate temperature measurements.
- Suspend the thermostat (1) and a thermometer (3) in the pan.
- Place the pan on a burner (2).
- Heat the solution.
- Use a thermometer (3) in order to measure the temperature of the
solution.
- Ensure that the following specifications exist:
| • | The thermostat valve opening temperature is within 80°- 84°C
(176°-183°F). |
| • | The valve lift is 8 mm (0.31 in) or more at 95°C (203°F). |
| • | If the above specifications are not met, replace the thermostat (1). |
- Verify that the valve spring is tight when the thermostat is fully closed.
Replace the thermostat if the spring is not tight.
