Water Pumps Available here. A vehicle water pump is designed to circulate coolant through the engine and radiator which then regulates the engine temperature. Water pumps are usually belt-driven by the engine and they use impeller blades to force coolant through the cooling system.A water pump is an essential engine part because it prevents engine overheating and dissipates heat generated by the engine, ensuring optimal performance. The symptoms of a bad water pump in a car is usually leakage, overheating, strange noises like squealing or whining and corrosion of the water pump. Leaking coolant from the front of the engine is often a sign of a water pump coolant leak. Shop for water pumps online with MicksGarage.com and save more now.