Thermostat Test

Replace the thermostat if it is stuck open at room temperature.

To test a closed thermostat:

1. Suspend the thermostat (A) in a container of water. Do not let the thermometer (B) touch the bottom of the hot container.
   Fig 1: Identifying Thermostat

   Courtesy of AMERICAN HONDA MOTOR CO., INC.
2. Heat the water and check the temperature with a thermometer. Check the temperature when the thermostat first opens, and when it is fully open.
3. Measure the lift height of the thermostat when it is fully open.

   Standard Thermostat 

   Lift Height: Above 8.0 mm (0.31 in.) 

   Starts Opening: 176-183°F (80-84°C) 

   Fully Open: 203°F (95°C)