Thermostat Test

WARNING: This page is about a different car, the 2008 Honda Pilot, 2007 Honda Pilot, and 2006 Honda Pilot. However, it is still accessible from the selected car via links, so may be relevant.

Replace the thermostat if it is open at room temperature.

To test a closed thermostat:

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

Fig 1: Suspending Thermostat In Container Of Water
Courtesy of AMERICAN HONDA MOTOR CO., INC.
Heat the water and check the temperature with a thermometer. Check the temperature at which the thermostat first opens, and at which it is fully open.
Measure the lift height of the thermostat when it is fully open.
Standard Thermostat
- Lift Height: Above 10.0 mm (0.39 in.)
- Starts Opening: 169-176°F (76-80°C)
- Fully Open: 194°F (90°C)