How to Replace the Thermostat of a 1999 Pontiac Grand Am SE

by Zyon Silket
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If the thermostat in your 1999 Pontiac Grand Am SE stops working, you run the risk of the engine overheating and warping. The repair bill to have an engine machined can be several thousand dollars. When you notice the temperature gauge going higher than normal, it is time to change the thermostat. It is likely that engine buildup has accumulated around the thermostat and has caused a mechanical failure. It's better to spend a few dollars to replace the thermostat then to allow it to become a costlier job.

Step 1

Locate the thermostat housing by following the top radiator hose from the radiator to the Pontiac's intake. The hose connects to the metal thermostat housing.

Step 2

Remove the radiator hose from the thermostat housing. Loosen the band clamp that secures the hose to the thermostat housing by using a screwdriver to turn the screw on the clamp counterclockwise. Pull the hose off the housing.

Step 3

Remove the bolts that secure the thermostat housing to the intake with a 10-mm wrench and pull up on the housing to remove it from the intake. Inspect the housing for any hairline cracks. If the housing is cracked, use a new one. Otherwise, use the old housing.

Step 4

Pull the old thermostat out of the intake of the Grand Am by pulling up on it. Discard the old thermostat. Place the new thermostat into the intake and orientate it in the same manner as the old thermostat.

Step 5

Remove the old paper thermostat gasket from the base of the intake and discard it. Place the new thermostat gasket onto the base of the intake and line up the bolt holes in the gasket with the bolt holes in the intake.

Step 6

Place the thermostat housing onto the thermostat gasket and bolt the housing onto the housing using the original 10-mm bolts.

Step 7

Push the hose back onto the housing and tighten the band clamp with a screwdriver.

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