How to Change the Thermostat on a Trailblazer

by Carl Pruit

As a sport utility vehicle (SUV), the Chevy Trailblazer allows you to travel over rough terrain and off-road places. The rugged design and larger engine size gives you a stronger-performing vehicle with the ability to haul larger loads. In order to keep your Trailblazer running properly, routine maintenance should be done on the performance and cooling systems. If you find your vehicle overheating, it may require you to change the thermostat. This can be done very easily and keep your Trailblazer running efficiently.

Place a drain pan on the ground under the radiator drain plug of your Trailblazer. Locate the thermostat housing that sits near the front of the engine at the top. The thermostat housing will be at the end of the upper radiator hose, connected to the motor.

Remove the radiator cap from the top of the radiator. Loosen the drain plug with a pair of pliers at the bottom of the radiator to allow the radiator coolant to drain until the fluid level is lower than the thermostat housing. Once the coolant level is below the thermostat housing, tighten the drain plug to shut off the release of coolant.

Remove the bolts that are holding the thermostat housing to the engine block with a socket wrench. Remove the thermostat from the thermostat housing. Clean the face of the thermostat housing and the engine block where the housing attaches. Remove any remaining gasket material or debris with a piece of emery cloth.

Place a small bead of gasket seal over the face of the thermostat housing. Place the new thermostat back on the housing with the spring facing out from the housing. Reattach the thermostat housing and the thermostat to the engine block by securing it with bolts.

Pour coolant into the radiator until the fluid level reaches the top, and then place the radiator cap back on the radiator. Start the engine, and allow it to run for about 5 minutes or until the motor is warm enough to verify that the thermostat is working properly.

Turn the engine off and remove the drain pan from the bottom of the radiator.

Tip

  • check Dispose of the drained coolant by taking it to the local recycling center or your local automotive center.

Warning

  • close Never work on an engine that is hot. Allow the engine to cool before you start doing any work.

Items you will need

About the Author

Carl Pruit has been a freelance writer since 2005, specializing in service journalism and travel. His work has appeared on various websites. Born and raised in California, Pruit attended Contra Costa Community College in San Pablo, Calif. and received an associate degree in the administration of justice.