Includes the water pump housing and thermostat. Your engine water pump is commonly a simple centrifugal pump driven by a belt connected to the crankshaft of the engine. The pump circulates coolant while the engine is running. The fluid leaving the pump flows through the engine block and cylinder head before entering the radiator and finally returning back to the pump. Replace your water pump if you notice a leak around the pump or its making more noise than usual. We also recommend replacing your water pump when you replace your timing belt, which is generally every 60,000-90,000 miles. Failure of this pump can cause overheating, and subsequent severe engine damage.