Repair 7

Finding a Toyota thermostat depends on the year and the engine motor you are dealing with. However, there are a few standard guidelines to follow when locating and servicing the thermostat.

Follow the Flow

Follow the upper radiator hose from the top of the radiator. Where the hose ends and clamps on is called the thermostat housing. This housing will be either on the intake manifold or the engine block.

Housing Removal

Sometimes in newer Toyotas this housing in under a plastic engine cover. This cover is easily removed, as it is held on by either a couple of bolts or a couple plastic clips. Once removed, the thermostat housing will be visible. Remove the radiator cap and unclamp the upper hose from the thermostat housing. This housing is held in place by two or three bolts.

The Thermostat

Once the housing is removed, the thermostat will be revealed. It should pull out easily at this point. Thermostats have either a rubber O-ring or a fiber gasket to keep the housing from leaking. Be sure to replace this gasket if the thermostat if replacing the device.

The cooling system on the 1991 Nissan pickups come equipped with a thermostat that regulates the engines temperature. The thermostat is made up of a temperature-sensitive spring that moves the thermostat up and down in reaction to the temperature of the coolant. When the engine is running, the thermostat regulates the coolant flow from the radiator to the engine, allowing only the proper amount of coolant throughout the engine block. If the thermostat sticks, replace it as soon as possible.

Instructions

1

Park the 1991 Nissan pickup on a level surface. Set the parking brake and open the hood.

2

Locate the top radiator hose that runs from the top of the radiator to the engine block. Follow the top radiator hose from the radiator to the thermostat housing. The hose is attached to the thermostat housing tube. Slide the fluid catch pan underneath the engine in the general area of the thermostat housing.

3

Loosen the hose clamp by turning the adjustable screw head counterclockwise with a flat-head screwdriver. Pull the clamp about 6 inches up onto the radiator hose. Twist the hose back and forth with your hand until it loosens from the thermostat housing tube. Pull the hose straight off the tube.

4

Loosen and remove the two mounting bolts from the thermostat housing with a ratchet and a socket. Pull the thermostat housing off the engine block and place it on a clean rag.

5

Pull the thermostat straight up out of the engine block. Scrape any of the old gasket off the base of the thermostat housing and the engine block with a flat scraper. Wipe the thermostat housing base and the engine block clean with a clean rag.

6

Place the thermostat gasket over the bottom of the thermostat housing base and push the two housing bolts through the holes to hold the gasket in place. Insert the new thermostat into the top of the engine block with the spring facing downward. Lower the housing back over the engine block. Screw the two mounting bolts into the engine block until tight. Finish tightening the bolts with the ratchet and socket.

7

Push the top radiator hose back over the thermostat housing tube. Position the hose clamp over the hose and over the thermostat housing tube. Tighten the clamp with the screwdriver until the hose is tightly secured to the thermostat housing tube.

8

Remove the radiator cap and add coolant as needed until the radiator is full. Crank the engine and let it run until the engine is at operating temperature or until the coolant level drops inside of the radiator. This will show that the thermostat is working properly. Inspect the thermostat housing and the top radiator hose for any leaks while the engine is running. Add more coolant if needed to fill the radiator up with the engine running.

9

Turn the engine off and pull the fluid catch pan out from under the truck.

The thermostat in the 4.3-liter GMC Sierra pickup truck regulates operating temperatures within the engine to prevent overheating and premature engine failure. This is a big task for a very small, inexpensive part. When the thermostat stops regulating properly, you will notice the temperature gauge in the dash start to rise. You will smell the sweet odor of overheating coolant and your truck will eventually pour steam out of the engine bay. Changing the thermostat is a fairly easy job that shouldnt take you very long at all.

Instructions

1

Lift the hood and prop it open. Position a drain pan under the drain valve on the bottom of the radiator. Loosen the radiator cap. Open the valve with a pliers. Drain two gallons of coolant into a clean drain pan. Close the drain valve with the pliers.

2

Follow the upper radiator hose to the thermostat housing, behind the alternator.

3

Remove the two bolts that secure the housing to the engine. Hose removal is not necessary to remove the thermostat housing.

4

Lift the housing up and shove it and the hose out of your way.

5

Pull the old thermostat out of the engine and place the new one in. You must place the new one into the engine and orientate it in the same manner as the old one.

6

Lift the old gasket off the engine, wipe down the surface with a clean towel and place the new thermostat gasket into place.

7

Place the thermostat housing back on the engine and bolt it into place.

8

Remove the radiator cap. Pour the two gallons of fluid back into the radiator. Replace and tighten the cap. Close the hood.

A mechanical automotive thermostat usually mounts in one of two locations on the engine -- on top, connected to the upper radiator hose or on the bottom, connected to the inlet on the water pump. Replacement of a top-mounted thermostat requires less time and fewer tools. Fortunately for Chevy Lumina V6 owners, the thermostat location is on the top of the engine. This makes the task of locating and replacing the thermostat an easier process.

Instructions

1

Open the engine hood on your V6 Lumina by pulling the hood release latch on the drivers-side kick panel, under the dashboard.

2

Locate the upper radiator hose connected to the back of the radiator.

3

Follow the upper radiator hose from the back of the radiator to the location where the hose connects to the engine. The hose mounts to the thermostat housing lid. The thermostat rests submerged in coolant inside the housing.

The thermostat in the 2006 Chevy Malibu regulates the engine temperature by allowing or restricting the flow of fluid that goes through the coolant veins inside the engine block and engine heads. At 180 degrees F, the thermostat opens and forces more fluid though the engine. This lowers the temperature in the engine to prevent overheating. At some point, the thermostat will fail. When this happens, the engine could overheat and cause thousands of dollars in damages.

Instructions

1

Remove the two bolts that secure the T-Stat housing to the right engine head. To locate the housing, follow the upper radiator hose to the engine head. The hose connects to the T-Stat housing.

2

Lift the T-Stat housing upward and remove the thermostat from the engine head.

3

Clean the old gasket off the engine head. Use a small scraper or wire brush if necessary.

4

Place the spring end of the thermostat into the engine head and then place the thermostat gasket over the thermostat.

5

Place the thermostat housing onto the gasket and bolt it into place.