How to Change a Ford Windstar Thermostatby John Stevens J.D.
The vast majority of engine overheating problems can be traced to a defective thermostat rather than a problem with the radiator itself. The thermostat operates like a switch to prevent the antifreeze within the radiator from circulating through the engine until the engine reaches its normal temperature when first started. A defective thermostat typically becomes stuck in the closed position, causing the engine to quickly overheat. Thankfully, replacement thermostats are fairly inexpensive, and replacing the Ford Windstar's thermostat is simple.
Remove the radiator cap, then remove the drain cock from the bottom of the radiator with a wrench to drain the radiator.
Remove the air box assembly hose. The air box hose is a large, black plastic hose that leads from the air box on the driver's side of the engine compartment to the front of the engine. The hose attaches to the front of the engine and to the black box with a single clamp on each end of the hose. Loosen the two clamps with a flathead screwdriver, then pull the hose away from the engine and the box to remove it.
Trace the upper radiator hose from the radiator to where the hose enters the engine. The metal piece that the hose attaches to on the engine is the thermostat housing. As its name suggests, the thermostat is located inside this housing.
Loosen the clamp that secures the upper radiator hose to the engine with a screwdriver, then pull the radiator hose away from the engine to disconnect it from the thermostat housing.
Remove the two bolts that hold the thermostat housing to the engine with a deep-socket connected to a socket wrench, then pull the housing off of the engine to reveal the thermostat. Pull the thermostat out of the engine.
Place the new thermostat into the engine with the spring located on one side of the thermostat facing toward the engine. Remove the gasket from the back of the thermostat housing, then apply gasket sealer to both sides of a new thermostat housing gasket. Lower the thermostat housing over the thermostat, then install and tighten the thermostat housing's two retaining bolts with a deep-socket connected to a socket wrench.
Push the radiator hose onto the thermostat housing, then tighten the hose clamp with a screwdriver.
Position the air box assembly hose onto the assembly, then press the opposite end of the hose onto the engine. Tighten both hose clamp's with a flathead screwdriver.
Install and tighten the radiator's drain cock with a wrench and allow at least two hours to pass for the gasket's sealer to harden. Fill the radiator with antifreeze and install the radiator cap to complete the replacement.