1. RADIATOR: Cools off the anti-freeze/coolant mixture by allowing air passing through the tube/fin area to dissipate the heat generated by the engine.
2. WATER PUMP: Draws the cooled anti-freeze from the radiator and pumps it through the engine block, cylinder head(s), heater core and back to the radiator.
3. FREEZE PLUGS: Is actually a steel plug designed to seal holes in the engine block and cylinder head(s) created from the casting process. In freezing weather they may push out if there is not enough anti-freeze protection.
4. HEAD GASKET /TIMING COVER GASKET: Seals the major parts of the engine. Prevents oil, anti-freeze and cylinder pressure from mixing together.
5. HEATER CORE: Provides heat to the interior of the car by using heat removed from the antifreeze and blown in by the blower motor. May cause steam, odor or actual dripping inside the car when it leaks.
6. THERMOSTAT: Controls the minimum operating temperature of the engine. The thermostat is closed when the engine is cold in order to speed warm-up and opens when normal operating temperature is reached to allow the anti-freeze/coolant to pass through the radiator.
7. HOSES (Radiator, Heater, By-pass):Connect the other main components of the cooling system. Hose manufacturers recommend replacing every 4 years regardless of appearance because there may be deterioration of the inside of the hose which cannot be seen.
8. FAN CLUTCH: Senses the temperature of the air coming through the radiator and either slips or binds up to pull the required amount of air through the radiator.
9. ELECTRIC COOLING FAN: Most front wheel drive cars use this because of the transverse mounted engine. It is turned on by a system of sensors and relays when the engine reaches about 230 F and stays on until R is cooled to about 200 F.