Engine Cooling Systems: Description

The basic liquid cooling system consists of a radiator, water pump, thermostat, cooling fan, pressure cap, heater (if equipped), various connecting hoses, and cooling passages in the block and cylinder head. In addition, many cars use a fan clutch, which may incorporate a thermostatic control, or a flexible fan blade, or both, to reduce noise and power requirements at higher engine speeds. Some models, with exhaust emission control, use a thermostatic vacuum switch to advance ignition timing in the event of overheating. Coolant recovery systems are being used more commonly to prevent loss of the recommended permanent (ethylene glycol) type, year round, anti-freeze.