What Is a Water Pump Assembly and Why Is it Important?

Your water pump is the heart of your Volkswagen’s cooling system. It is located in the engine compartment. The water pump circulates coolant throughout the engine and radiator. The purpose is to keep the engine at the right operating temperature.

How a Water Pump Works

Water pump new

The water pump is a basic centrifugal pump powered by the engine via the serpentine belt. It uses impeller blades to pump coolant throughout the engine and then the radiator. The water pump assembly has five basic components:

  • Impeller
  • Pulley
  • Seal
  • Bearing
  • Housing

The pump creates enough centrifugal force to draw coolant out of the radiator and then circulate it throughout the engine.

What Happens When Your Water Pump Fails

A failing water pump won’t circulate enough coolant through the engine block, and this will result in an overheated engine. If the water pump is not repaired or replaced immediately, there will be additional engine damage. The damage can be severe, such as:

  • Blown head gasket(s).
  • Burnt pistons.
  • Cracked cylinder heads.

In extreme cases, the engine oil and coolant will rise to temperatures that can damage other components in the engine. Basically, your engine needs a functioning water pump to operate without damage. To prevent severe engine damage, keep an eye out for the following symptoms of a failing water pump:

  • Coolant leaking from the water pump weep hole.
  • Whining sound from the water pump.
  • The pulley wobbles when the engine is running.
  • The engine temperature gauge running on the hot side frequently

Why Get an OEM Replacement Water Pump?

Old new pump

Image Credit: kern417

If you’ve determined that your water pump is indeed bad, you’ll have to replace your water pump.

One of the first decisions you’ll have to make is to whether buy an OEM replacement water pump or an aftermarket water pump. We strongly suggest going the OEM route because:

  • Many aftermarket water pumps are built with universal components such as impellers and bearings. Volkswagen OEM water pumps are built to specific criteria for VW model.
  • Often times with aftermarket water pumps, the quality is questionable. Many aftermarket water pump manufacturers use low-quality materials to cut corners. If you buy an OEM water pump, you don’t have to worry about ending up with a low quality part. All OEM parts are made with high-quality materials.
  • The right OEM parts are so much easier to find. While looking for an aftermarket part, you’ll have to do tons of research. You'll really have to dig into the brand and fitment to make sure you’re buying a good water pump. The pump needs to fit your Volkswagen properly and perform well for a long time. With OEM parts, quality, fitment, and longevity are guaranteed. You just have to look up your Volkswagen in our catalog to find the right water pump.

For your convenience, we’ve included a couple of quick links to our top selling water pumps:

  • Part No. 06A-121-012-G: For 1999-2006 Passat, Jetta, Golf, and Beetle models
  • Part No. 06H-121-026-DD: For 2012-2017 Tiguan, Jetta, GTI, Eos, CC, and Beetle models