How Do I Change a Thermostat on a 2002 Volvo V-40?

Damage to a car's thermostat occurs most often from corrosive buildups caused by failed cooling system maintenance. This can cause the thermostat to become jammed in the closed position. The result can cause the engine to overheat and fail. With a few minor tools, you can replace the thermostat in the 2002 Volvo V40 yourself, right at home. The total repair time should take 40 minutes or less.

Instructions

1

Raise the hood on your V40 and remove the radiator cap. Set the cap to the side and then place a coolant drain pan under the radiator on its right side--inline with the drain plug.

2

Reach down into the engine compartment and turn the drain plug counterclockwise until coolant starts to flow out of the radiator. Allow the coolant to drain for approximately 70 seconds, then close the drain plug securely.

3

Stand directly inline with the top radiator hose. If you observe the hoses connecting points, you will see that one side of it attaches to the radiator and the other to the engine. The end of the hose that attaches to the engine actually attaches to the thermostat housing.

4

Loosen the screw on the hose clamp with a flat-head screwdriver. Draw the clamp back on the top radiator hose 12 inches. Pull the hose away from the thermostat housing and lift it up vertically for three seconds, then set the hose back down. This will allow the remaining coolant in the hose to flow backward into the radiator.

5

Attach a Torx socket to your socket wrench. Remove the three Torx bolts that secure the thermostat housing in place. Lift the housing off the thermostat and set it to the side. Remove the rubber gasket that surrounds the thermostat and discard it. Lift the thermostat straight up and out of its mounting position.

6

Insert the new thermostat--spring down--back into place just as the old one was positioned before you removed it. Place your new rubber gasket down over the thermostat. Before you put the thermostat housing back on, make sure that the gasket is lying completely flat.

7

Place the thermostat housing back over the new thermostat. Thread all three of the housings Torx bolts by hand. Attach the Torx socket to your 3/8-inch-drive torque wrench. Set the torque wrench to 16 foot-pounds and secure all three of the Torx bolts in place.

8

Push the top radiator hose back onto the thermostat housing just as you removed it. Slide the hose clamp back down the hose to its previous mounting position. Tighten the clamps screw with your flat-head screwdriver three-quarters past hand tight.

9

Insert a funnel into the radiators fill hole. Refill the radiator with the coolant that you drained into the coolant drain pan. Put the radiator cap back on and shut the hood.