The Buick Regal GS is a full sized four-door sedan that's capable of driving around five people in luxury. An often-overlooked aspect of auto maintenance is the fluid system. The radiator fluid runs through the engine and a mechanical thermostat controls the amount of fluid. If that mechanical thermostat stops working, you may find that the heat no longer works or the engine overheats. However, replacing a thermostat doesn't take much time.
Open the radiator cap to release the pressurized fluid system in the Buick Regal GS. It's possible that the radiator will mist or push fluid out of the radiator filler hole when the cap is removed. For this reason, the engine should be cool when this step is performed.
Remove the radiator hose from the cover that holds the thermostat in place. The cover is located on the Buick's air-intake manifold. Loosen the clamp that holds the hose onto the cover with a Phillips screwdriver. Pull the clamp onto the hose and push the hose off to the side.
Remove the cover that holds the thermostat on by removing the two bolts that hold it to the air-intake manifold. Set the cover and the bolts off to the side. They will be reused during the installation process.
Discard the old thermostat gasket and place a new gasket into place. Pull out the old thermostat and replace it with a new one. The thermostat is not bolted into place and can be removed by pulling up on it. Discard the old thermostat.
Reattach the cover that holds the thermostat into place with the bolts. Do not over tighten the cover. It's possible to break the cover since it is made with soft "cast" metal.
Reattach the radiator hose and tighten into place with the camp. Refill any lost antifreeze and replace the radiator clamp.
Start the engine and check the radiator hose and the mating surfaces of the air-intake manifold and the thermostat cover for any leaks. If there is a leak where the hose clamps onto the cover, tighten the hose clamp. If there is a leak around the thermostat seal, the cover should be removed and a fresh gasket with PVC gasket sealer should be used.
