Radiator

An assembly of tubes and fins that transfer heat from the engine coolant into the passing air stream. This process is aided by mechanical and/or electrical fans that pull/push additional air through the radiator as needed.

The radiator sits in the very front of the grill and has an upper and lower radiator hose attached to it. Hot coolant enters the radiator through the upper radiator hose after the thermostat open. The hot antifreeze if cooled by heat transfer in the passing air, then the cooler antifreeze re-enters the engine from the lower radiator hose.

The coolant flow is caused by the engine turning the water pump which pushes it into the radiator and pulls it from the radiator. Today these are normally made from plastic and copper.