The 1997 Mercury Sable came with a 3.0-liter engine. The 3.0-liter was water-cooled like any traditional gasoline-powered combustion engine. It uses a water pump to push coolant (a 50/50 mix of water and antifreeze) up through the engine block and out via a rubber radiator hose to the radiator, where the fluid cools. One end of the upper radiator hose attaches to the radiator and the other attaches to a thermostat housing on the engine. The thermostat is a temperature-controlled valve that, when the engine's operating temperature reaches a certain temperature, opens to allow the hot coolant to circulate out of the engine. The water pump on bottom pumps cooled coolant into the block. When the thermostat sticks or fails, the engine may overheat and damage the block. Replace the thermostat as soon as you notice the car is overheating. Buy a thermostat from an auto parts retailer and replace it at home to save the cost of a bill from a service center.
Instructions
- 1
Open the hood of the Sable. Remove the cap from the radiator. Position a drain pan under the radiator drain plug on the passenger side of the car.
2Remove the drain plug from the bottom of the radiator, using a wrench. Wait for the coolant level to drain until it is just below the upper radiator hose. Replace the radiator drain plug and tighten it completely.
3Trace the upper radiator hose to the thermostat housing on the engine. Remove the three bolts securing the housing to the mounting surface with a wrench. Remove the gasket and thermostat body from the housing. Be sure every bit of the gasket is removed.
4Insert the new thermostat in the housing. Install a new gasket on the thermostat housing. Secure the thermostat housing to the mounting surface, and torque the mounting bolts to 9 pound-feet with your torque wrench.
5Add a 50/50 blend of antifreeze and distilled water to your Sable's radiator until it is full. Replace the radiator cap. Start the engine and let it warm up to verify that there are no coolant leaks.
