The thermal regulation of your cooling system is controlled by the Pontiac Thermostat. This cooling component is located on the top front of the engine and its housing has the upper radiator hose attached to it.
The makeup of the thermostat is of a valve that opens and closed by the action of a bimetal spring on your Pontiac that is surrounded by a housing unit. The use of the bimetal spring is to set the exact temperature at which your Pontiac thermostat will open and close.
From time to time the thermostat will fail to open which will cause your engine to overheat. If this occurs to you the upper coolant hose can be removed from the thermostat housing and a screw driver can be jammed down into it opening the valve. This will permanently damage this cooling temperature controlling device, but you can run your engine and go to a repair shop or auto parts store to get the correct part so your cooling system on your Pontiac can be repaired.
On occasions the valve in the thermostat might also become stuck open. This will be noticed when the engine never reaches its proper operating temperature. The heating unit in the passenger compartment will also not be able to produce enough heat for the passengers to be comfortable in the winter. This is another situation when this engine temperature controlling device should be replaced.
The temperature your engine should run at is determined by the factory after many tests have been conducted on it. Changing the range at which this valve will open releasing the coolant could adversely affect the performance and efficiency at which you Pontiac engine operates.