Thermostat: Description and Operation

When the coolant is cold, the water thermostat is in the closed position and the coolant flow is limited to the cylinder block, cylinder head heater system and the degas bottle.

As the engine coolant temperature increases, the water thermostat opens and allows a portion of the coolant to pass into the radiator.

The water thermostat is located in the water hose connection which is attached to the rear of the lower intake manifold.