Features

• A water pump is metal and attaches to the front of your engine with a seal. Inside the metal housing resides a rotating shaft and a centrifugal pump. The opposite end not attached to the engine has a pulley mount for the belt to sit on and rotate.
  
  

Significance

• The water pump operates when your engine is running. It pumps cool water and coolant into the engine block and head, and then exits the engine through a hose into the radiator. The coolant circulates through the radiator to lower its temperature and then travels back to the water pump through a hose and into the engine again. This cycle repeats as long as the engine is running.
  
  

Temperature

• If your water pump is not working effectively, you will notice a rise in the engine temperature. This is observable on the temperature gauge inside your vehicle. It is a good idea to know where the gauge rests in normal operation so that you will notice a higher-than-normal temperature reading. Some vehicles also will alert you to the high temperature by activating the check engine light. Most auto parts stores can attach a meter to your car and retrieve the trouble code so that you can replace the part.
  
  

Leaks

• When a water pump fails, it will usually become hot, blow the seal and start leaking. If you are adding water to your radiator or radiator overflow canister on a continual basis, then there is a water leak. To see if it is the water pump, you can place a piece of cardboard directly under the water pump at night and check to see if it is wet from leaking water and coolant the next morning. You can also feel the bottom side when the engine is cool to check for leaks.
  
  

Noises

• If the drive belt or timing belt, which operates the water pump, is loose from wear, it will cause the pump to operate inefficiently. The belt should be tight and you should be able to observe minimal slack in it when you push it with your fingers. If the belt is slipping, it will make a squealing noise and should be replaced. If you notice a rattling or growling noise, it may be the impeller or the bearings that have failed in your water pump. This will cause ineffective or no coolant to be pumped into your engine.