Easy guide on how an automotive cooling system thermostat works, this information
pertains to most vehicles.
An engine cooling system thermostat is designed to stop the flow of coolant in
the cooling system when the engine is cold, this is done to help the engine warm
up to optimum operating temperature which improves efficiency and emissions output.
Once the engine heats to 195° F or 96° C it will open allowing the radiator to remove
heat from the coolant so it can be circulated back into the engine. These units
are located either at the upper or lower radiator hose connections.