The water pump circulates coolant through the radiator and engine to keep it cool. In addition to your cooling system, there are small hoses that feed off of your engine and circulate coolant to the heating core, which provides hot air for the cabin when your heater is turned on.
The water pump is often driven by the timing belt. We recommend changing the water pump whenever the timing belt is replaced as the cost of a new water pump is insignificant compared to the amount of work required to access the timing belt and water pump. If the water pump is driven by the timing belt, it will be difficult to see as it is hidden under the plastic timing belt cover.
Common signs that your water pump is failing includes coolant leaks from the water pump, engine overheating and rumbling sounds from the water pump itself. If the water pump is making a rattling or rumbling sound, it is likely due to the impeller breaking or becoming disconnected from the drive shaft in the water pump itself.