How do you replace the thermostat on a 2000 Pontiac Montana 3.4?

Answer 1

1. Drain cooling system. 2. Remove throttle body assy to make room. 3. Remove heat shield from the exhaust crossover pipe. 4. Disconnect crossover pipe from forward exhaust manifold. NOTE Crossover pipe should be slightly flexible enough to allow access to the bolts holding the water outlet housing on.

5. Remove hose, disconnect water temp sensor, and remove bolts from water outlet housing. 6. Remove outlet housing and replace the thermostat in the same direction as the original. (Also a good idea to replace the sensor since you already have the housing off the vehicle.)

Installation is the reverse.

Purge air from the cooling system by slightly loosening the two brass bolts (1 ea on the water pump and the thermostat housing) to allow trapped air to escape.

Check for leaks