How does an automobile radiator system work?

The radiator consists of cooling fins around tubing which the coolant flows through. A water pump circulates coolant from the radiator through the engine. A smaller radiator around the dashboard makes up the car's heater.

An automotive cooling system has 6 basic components; the radiator, coolant/water, pressure cap, expansion tank, thermostat, and the water pump. When an engine is running, the water pump circulates the engine coolant inside the engine. As the engine heats up, the thermostat opens (usually at above 160 degrees), which allows the engine coolant to be pumped into the radiator, through the top radiator hose. The coolant flows through tubes inside the radiator, and is cooled by air passing over the car's grill. The cooled coolant exits the radiator and reenters the engine through the bottom radiator hose. The pressure cap holds the entire cooling system under pressure, which allows the coolant to reach higher temperatures without boiling. The expansion tank holds extra coolant for the system and allows for extra capacity when the coolant expands with the heat.