Your car's coolant pump keeps coolant moving through the engine block, hoses and radiator, which helps the system to maintain the engine at the ideal operating temperature. It is driven by a serpentine belt (aka accessory belt or auxiliary belt) from the crankshaft pulley.
A car’s coolant pump uses impeller blades and centrifugal force to move the coolant around the car’s engine - or rather the water jacket that sits around the engine’s cylinders.
Once the liquid has flowed around the engine it travels along hoses to the radiator, where it is cooled by the movement of air through the radiator’s fins. It then exits the radiator and flows back into the water pump, where the process starts over.
Water pumps can suffer from a few problems. A grinding noise from the water pump indicates worn bearings. These can sometimes be replaced but it’s easier to get a new pump.
A leak from the pump could be a sign that the shaft seal or the gasket that sits between the pump and the engine has failed. If it’s the shaft seal, the entire pump will need to be replaced, but if it’s the gasket the pump can be removed, a new gasket fitted and the original pump replaced.
At the same time, check that all of the hoses are intact and not leaking.
Some modern coolant pumps have plastic impellers (fan blades) and these sometimes break. This leads to vibrations which in turn cause the pump to fail.
Maintaining a healthy coolant pump is easy: you need to make sure the engine coolant is in good condition and has the correct amount of antifreeze.
The latter stops the water freezing in cold temperatures and acts as a rust inhibitor, preventing small particles from breaking off inside the engine and wearing the pump’s parts.