How to Change the Thermostat in a Ford Explorerby Contributor; Updated November 07, 2017
Items you will need
10mm wrench or socket
Thermostat and gasket
How to Change the Thermostat in a Ford Explorer. If you're driving the popular Ford Explorer, and you have an overheating problem, or you find the heater is not blowing warm air, you'll likely need to change the thermostat. In less than an hour you'll have the problem fixed and your Explorer will once more be operating at peak performance.
Drain the coolant from your Explorer into an adequate container by opening the drain plug at the bottom of the radiator. Save the coolant for reuse if it is relatively new and clean.
Remove the negative battery cable from the battery if your Explorer has a 2.9-, 3.0-, 4.0- or 5.0-liter engine. This step is not necessary for 2.3- and 2.5-liter engines.
Follow the upper radiator hose to the front driver's side of the intake manifold, where it meets the engine. This is where the thermostat housing on your Ford Explorer is located. If necessary, remove the air cleaner duct for easy access to the housing.
Loosen the clip on the end of the radiator hose and pull the hose off the thermostat housing. Use a 10mm wrench or socket to remove the two retaining bolts on the thermostat housing cover. Remove the cover.
Note the position of the thermostat before removal. Pull out the old thermostat. Seat the new thermostat inside the housing in the same position as the old one, spring-side facing into the engine. Install new gasket over the thermostat.
Reattach the thermostat housing cover and the radiator hose. Reinstall the air cleaner duct if removed earlier. Fill the radiator with reserve or new coolant. Start your Explorer and run with the heater blowing until the engine gets warm. Check for leaks.
Do not attempt to drain the coolant from your Explorer if the engine is hot. Make sure the engine is cool before draining coolant.