How to Change a Thermostat in a Buickby Christian Killian
The thermostat is located in the water jacket near the output side of the radiator on most cars. The Buick V6 and V8 engines use a housing on the top front of the motor that directs coolant from the motor to the radiator through a rubber hose. The thermostat sits inside the housing and opens when the coolant reaches a preset temperature. If the thermostat fails to open, the results will be an overheating engine. If it never closes, you will not get heat in the winter because the coolant will never get hot enough.
Position a bucket or drain pan under the radiator drain located at the bottom of the radiator. Open the valve and drain the radiator down below the upper radiator hose fitting on the radiator then close the drain valve. You can open the fill cover on the radiator to verify the level.
Locate the thermostat housing on the top front of the engine. There will be two or three bolts retaining it.
Remove the hose clamp holding the upper radiator hose to the housing. Loosen the clamp with a screwdriver. Remove the clamp and the hose. Set the hose aside for now.
Remove the retaining bolts on the thermostat housing and carefully lift it off the engine. It may be stuck to the block, so slide a putty knife under the lip and carefully pry it off.
Lift the old thermostat out of the engine and discard it. Use the putty knife to scrape any old gasket material from the housing and the engine. Use care not to drop any debris into the opening where the thermostat sits.
Position the new thermostat in the hole on the engine making sure that it is sitting flush with the lip around the edge of the hole. If the thermostat is not down flush, tightening the housing could damage the thermostat, the housing, or cause a leak around the housing.
Lay the new gasket over the thermostat, making sure there is no debris or old gasket material under it. Install the housing over the thermostat and gasket and reinstall the retaining bolts. Snug the bolts down and then torque them to the specifications outlined by the manufacturer.
Reinstall the hose onto the housing, securing it with the hose clamp. Do not over tighten the clamp or the hose may be damaged.
Refill the radiator with coolant and check for leaks. If none are found, start the engine and allow the motor to warm up. Check the temperature and watch for leaks as the system builds pressure.
Test drive the car and verify that everything is working as it should.
- Using a clean bucket or drain pan will allow you to reuse the coolant you drained from the radiator when you refill it.
- Do not use RTV or other sealers on the housing in place of the gasket. If a piece comes loose it could damage the thermostat or cause it to stick open or closed.