How to Replace the Thermostat on a 1992 Buick Century

Buick first introduced the Century in 1936 to replace their Series 60 model. The 1992 model was midway through the first generation of the "A-body," front-wheel drive Centuries. While the drive train configuration changed, the need to maintain proper engine temperature stayed the same. The engine coolant thermostat regulates the engine temperature by opening and closing, depending on the engine temperature, in order to optimize fuel combustion and prevent overheating. While not mandatory, it is a good idea to replace the thermostat whenever you perform cooling system repairs or maintenance.

Instructions

1

Open the Century's hood. Follow the upper radiator hose from the engine to the coolant outlet housing, on the upper portion of the engine's side (the side facing the front of the car). Slide the drain pan under the engine until it is placed directly below the coolant outlet housing.

2

Remove the bolts holding the coolant outlet housing to the engine, using a socket wrench and an 8 mm socket. On cruise control equipped models, you'll need to remove the vacuum modulator bracket from the coolant outlet housing with the socket and wrench first.

3

Pull the coolant outlet housing off the engine, by hand. Shove a rag into the outlet housing to prevent debris from entering the engine.

4

Note the orientation of the old thermostat, then remove it from the housing, by hand. Shove a rag into the housing to prevent debris from entering the housing.

5

Clean the sealing surface on the engine and housing, using a gasket scraper. Wipe the area clean with a rag. Apply a 3 mm bead of RTV gasket maker into the gasket groove on the housing.

6

Remove the rags from the engine and coolant outlet housing. Place the new thermostat into the housing, making sure it has the same orientation as the old thermostat. Bolt the housing to the engine, using the socket wrench and socket (and reattach the vacuum modulator if you removed it earlier).

7

Start the engine and let it run until the temperature gauge reaches operating temperature. Fill the coolant overflow tank to the "Hot Fill" mark with a 50-50 mixture of Dexcool and distilled water. Inspect for leaks around the coolant outlet housing.

8

Recheck the coolant level and top off, as needed, after 50 miles of engine operation.