An engine cooling system is a system that uses either air or liquid to remove the waste heat from an internal combustion engine. The cooling system is designed to allow the engine to warm up as quickly as possible and then maintain a constant engine temperature. The main function of a cooling system is to ensure that the engine runs at its optimum operating temperature. If the cooling system or any part of it fails, it will overheat the engine, which can lead to many serious issues. The key components of a cooling system include:
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Radiator: The radiator acts as a heat exchanger for the engine. It is usually made of aluminum and has many small diameter pipes with fins attached to them. It exchanges the heat of the hot water coming from the engine with the ambient air. It also has a drainage plug, an inlet port, a sealed cover, and an outlet port.
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Water Pump: The water pump (or coolant pump) circulates coolant through the engine, hoses, and other components.
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Thermostat Valve: The thermostat valve opens when the desired operating temperature is reached.
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Expansion Tank: Most vehicles now employ an expansion tank that allows the coolant to expand and exit the cooling circuit when hot, and to return when the car is turned off and the engine cools.
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Fan: The fan or fans ensure adequate airflow for radiator cooling.
Liquid-cooled engines are able to vary the size of their passageways through the engine block so that coolant flow may be tailored to the needs of each area. Only the fixed parts of the engine, such as the block and head, are cooled directly by the main coolant system. Moving parts such as the pistons, and to a lesser extent the crankshaft and connecting rods, must rely on the lubrication oil as a coolant, or to a very limited amount of conduction into the block and thence the main coolant. The cooling system also incorporates elements of the cabin’s ventilation system, because engine heat is used to warm the car’s interior.
