To know what the heck a water pump IS, we must first explore what the heck a water pump IS NOT. A water pump is not:

  1. A type of shoe prominent in the 1990s
  2. Aquaman’s favorite energy drink
  3. A wet handshake-like gesture
  4. An organ inside a camel’s hump(s)

This is why I usually doodle stick figures.

This is why I usually doodle stick figures.

So…what the heck is it then?

A water pump is part of an engine’s cooling system. It helps circulate the water/coolant that keeps the engine from overheating.

It looks a little something like this.

It looks a little something like this.

How Does It Work?

Inside the water pump housing is an impeller. It looks like this: img_4729

The pump has a hub (connected to the impeller by a shaft). The hub is usually attached to the crankshaft with a belt, so when the engine is running and the crankshaft is rotating, the hub and impeller are spinning! That spinning creates centrifugal force, which draws in the water/coolant from the radiator, and pushes it out to the engine. That water/coolant absorbs the heat from the engine (created by friction and burning of the air/gas mixture) and brings it to the radiator to be cooled down again.

So, to put it in extremely technical scientific language:

  1. Engine turns cranky-thingy
  2. Belt connects cranky-thingy to spinny-fan-thingy
  3. Spinny-fan-thingy turns to make cool water go to hot engine
  4. Engine not so hot anymore

[Cue inspirational music]

[Cue inspirational music]

Common Problems

The most common problems with water pumps include:

  • Cracked housing
  • Broken seals
  • Noisy bearings
  • Broken impeller
  • Broken shaft

These issues can result in a coolant leak or broken bearings, which could lead to an overheated engine, so it is imperative that you have the water pump repaired if it ever fails.


So, there you have it. Now you know what the heck a water pump is NOT, what it IS, and the important part it plays in your engine’s cooling system.

Tell me what other automotive parts baffle you. I’ll tell you what the heck they are!


Written by Ben Scharff

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