Here's why the cooling system is so important to your engine's function:

The cooling system is responsible for keeping the temperature of the engine block and oil at optimal operating temperature.

Here you can see the cooling system circuit of hoses that goes around the engine.



Here's the electric fan, mechanical fan (clutch and pulley) and oil cooler that sit near the front:



The thermostat controls the flow of the coolant and activates at 82C, allowing the flow of coolant to flow through the engine block:


It consists of a wax membrane that melts when the temperature is reached, releasing the valve against its spring pressure:


The engine block and head has cooling jackets around the cylinders to keep it cool:


This timing chain driven water pump keeps coolant flowing throughout the system:


The radiator is a giant heat exchanger that cools antifreeze as it flows, transferring it to the air around the fins to by whisked away by the fans:



The fan clutch is a viscous coupling with a thermally activated spring on the front that responds to the immediate air temperature.