Thermostat Test Procedure Using Glycol
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2003 GMC Yukon XL, 2003 GMC Yukon, 2003 Chevrolet Tahoe, 2003 Chevrolet Suburban, and 2003 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
Inspect the operation of the thermostat by hanging the thermostat on a hook in a 50/50 percent solution of DEX-COOL® and clean drinkable water.
In order to inspect if the thermostat valve is opening properly, perform the following test:
- Completely submerge the thermostat in the glycol solution. The solution should be 11°C (22°F) above the temperature indicated on the thermostat valve.
- Thoroughly agitate the solution. Under these conditions, the thermostat valve should open.
In order to inspect if the thermostat valve is closing properly, perform the following test:
- Completely submerge the thermostat in a glycol solution. The solution should be 6°C (10°F) below the temperature indicated on the thermostat valve.
- Thoroughly agitate the solution. Under these conditions, the thermostat valve should close completely.