Installing a Car Thermostat

Installing a car thermostat is a quick and easy fix that can save you from expensive heat related engine damage. For under $10 (plus the cost of engine coolant), a balky car thermostat can be replaced in less than an hour.

Installing A Car Thermostat And Getting It Right

• Stay frosty. Make sure to allow your car's engine to cool completely before starting. Opening a hot radiator is a recipe for disaster and a painful mistake you'll only make once.
• Draining coolant. With a catch pan under your radiator, open the valve at the bottom of the radiator and drain as much coolant as you can from the engine.
• Find your thermostat. Your thermostat will be under a housing connected to radiator hose running from the top of the radiator to the top of the engine. If you have trouble locating the thermostat housing, check you vehicle's repair manual.
• Disconnect the radiator hose. With a catch pan on the ground under the thermostat housing, unhook the clamps holding the radiator hose to the housing. Look out for coolant that will spill from the hose when it comes loose.
• The thermostat housing. Remove the thermostat housing by loosening the bolts holding it to the engine block. An appropriately sized socket wrench with an extension will make this job easier.
• Remove the old thermostat. Take note of the position and orientation of the thermostat when the housing is removed. Pull the thermostat from its position under the thermostat housing and place it aside.
• Clean up the gasket. Use a paint scraper to remove the remains of the old gasket from the base of the housing and from the engine area around the thermostat. Use steel wool to remove any leftover gasket or adhesive-getting down to bare metal will insure a tight seal.
• Replace the thermostat. Drop the new thermostat into place, making sure it matches the position and orientation of the old unit. Make sure the new thermostat sits flush into position.
• Install the new seal. Affix the gasket to the thermostat housing with sealant, making sure the bolt holes line up correctly. Also, make sure the gasket is smooth and flat to insure a good seal.
• Putting it back together. Replace the thermostat housing and tighten down the bolts holding the housing in place. Attach the radiator hose to the housing and tighten the clamps completely.
• Don't forget the coolant. Close the valve at the bottom of the radiator and fill the radiator with coolant-use your owner's manual to determine the type and amount of coolant to use. Start the car with the radiator cap off and carefully note the level of the coolant within the radiator. Add extra coolant if needed and then screw the radiator cap back in place.