The water pump, a container made of aluminum or iron, is part of the cooling system. It contains an impeller (looks like a fan) that circulates water and coolant throughout the cooling system, keeping the engine from overheating. It is located in the engine compartment. For the water pump to work, it needs to turn. This is accomplished either by the drive belt or timing belt/chain. If the water pump is not working, the coolant will not circulate through the cooling system causing the engine to overheat and get severe damages.