For your car, coolant is just as important to keep topped off as any other fluid. It protects your engine from high heat as well as freezing temperatures. The water pump cycles coolant from the radiator throughout the engine, absorbing the heat and wicking it away into the atmosphere. When water pumps go bad, it causes your engine to overheat—and that leads to all sorts of trouble.

While water pumps are designed to last a vehicle’s lifetime, it’s entirely possible for them to fail before that mark. Every part of a water pump is critical to its function, and damage to any of of them could lead to failure. So how do you know if your water pump is failing?

Indications of a Faulty Water Pump

Under hood

Your car will tell you when the water pump is out of whack. Look for these signs:

Leaking Coolant

If you discover a puddle of fluid underneath your engine, that could be a sign of a bad water pump that’s leaking coolant. This happens when:

  • The water pump isn’t installed correctly. Deformations, over tightening, or a faulty bearing could cause a bad installation.
  • The body is fractured. This often happens during installation and can even happen during shipping.
  • The bearing seal has failed. This can be caused by rust, sediment, and other contaminants that circulate throughout the cooling system.
  • Coolant seeps through the weep hole. While some seepage occurs on new water pumps while they’re breaking in, excess dripping signifies contaminated fluid and impending water pump failure.
  • There’s a leak somewhere in the cooling system other than the water pump. If you’re losing coolant for a reason not mentioned above, you likely have a leak in your radiator or one of the hoses in your system.

Note that if a leak isn’t taken care of, your engine is almost guaranteed to overheat if the water pump isn’t replaced immediately.

Grinding Noises

Grinding noises can be an indicator of a few different water pump failures, including:

  • A worn bearing seal. Leaking coolant will slowly dissolve the protective layer surrounding the seal, causing it to overheat and eventually collapse. A collapsed bearing WILL directly effect your engine.
  • A fractured body. This could be corrosion caused by coolant deterioration.
  • A loose water pump pulley. This is usually the sign of a bearing going bad.

    Photo credit: Pete via flickr
  • A defective impeller coming loose from its shaft. The impeller’s job is to distribute coolant throughout the system, and if it were to detach, overheating would occur.

Engine Overheating

A failing water pump will cause your engine to heat up, and that’s not a good thing. To prevent catastrophic engine failure, look for these signs of an overheated engine due to water pump failure, including:

      • A fluctuating temperature gauge. Normally, your vehicle’s temperature gauge should remain steady, settling somewhere between cold and hot. If coolant isn’t getting pumped through the system, the impeller has most likely malfunctioned. This causes the temperature gauge needle to go up.
      • A check engine light. Overheated coolant will trigger the dreaded check engine light, which means it’s time to pull over immediately.


      • Dirty, clouded coolant. If the coolant in your system has becomes contaminated, that can impact the system’s ability to keep your engine cool. Look for signs of exceptionally dirty coolant. Coolant is typically a bright color (coolant cover varies from one vehicle to another) and shouldn’t have any oil or debris in it.

WaterPumpBuying a New Water Pump

A faulty water pump has the ability to cause complete engine failure. That reason alone should be enough to only purchase a water pump from a premium OEM-quality manufacturer.

At GMB, we’ve been manufacturing high-quality water pumps for decades. Our clients include various automakers, well-known national parts chains, and premium after-market brands. When we manufacture water pumps, we focus on the individual components so the whole part meets our high standards. Lastly, we are sure to match the OEM specifications for every single water pump we make. That way, you get the perfect fit every time.

Learn more about GMB water pumps here!


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