Symptoms of a Bad or Failing Water Pump

In order to run cool on those hot summer days, your engine needs to have a consistent flow of coolant supplied from the radiator throughout the engine. The water pump is the primary component responsible for maintaining this flow. When it works properly, your car will maintain a consistent operating temperature, run smoothly, and take you anywhere you need to travel. When the water pump fails or is beginning to wear out, it can lead to complete engine failure.

When the water-cooled (as opposed to air-cooled) engine was introduced, many automotive experts believed that the water pump circulating coolant through the engine block was just as critical to engine protection as oil. This philosophy holds true even as technology improves over the years to create more efficient cooling systems in today's modern cars. Your car’s water pump is the key to making the entire system work. It is an impeller pump and is usually buried under the timing belt cover on the side of the engine. The pump is operated by the engine’s drive belt – as the belt turns, the pump turns. Blades on the pump force coolant to flow through the engine and back to the radiator to be cooled by a forced air cooling fan.

Although the water pumps in most modern cars, trucks, and SUVs will last a long time, they are by no means indestructible. Like any other mechanical device, they will produce a few warning signs of wearing out, so that car owners can contact a local ASE certified mechanic to replace the water pump before additional engine components are damaged.

Here are 5 common symptoms of a bad water pump:

1. Coolant Leak at the Front-Center of your Car

The water pump is comprised of multiple gaskets and seals that keep coolant contained and ensure that consistent flow of coolant is delivered from the radiator to the engine. Eventually, these gaskets and seals will wear out, dry up, crack or break entirely. When this happens, coolant will leak from the water pump and drop to the ground, typically in the front of your car and in the center of the motor's location. If you notice there is a leak of coolant (which will appear to be green or sometimes red in color) under the center of your car, truck or SUV, contact a professional mechanic to inspect this problem. More often than not, it's a leak from the water pump that can be repaired before it gets worse.

2. Rust, Deposit Buildup, and Corrosion of the Water Pump

Gradual leakage over time will cause different minerals to build up around the pump. Check under the hood, and you may notice rust on the pump’s surface from contaminated or non-compatible coolant mixtures or a defective pressure cap that lets in excess air. The wrong coolant will also cause deposit-buildup inside the pump, which slows the ideal process of engine cooling. In addition to these signs of wear, you may also notice small holes from corrosion in the metal, or cavitation – vapor bubbles in the coolant liquid that collapse with enough force to create cavities on the mounting surface. Should you notice these symptoms, replacement of the pump should be sought out immediately.

3. Water Pump Pulley is Loose and Making Whining Sounds

From time to time you might hear a high pitched sound that comes from the front of the motor. This is typically caused by a loose belt that creates a harmonic buzzing or whining sound as it circulates. The loose belt is commonly caused by a pulley that has become loose or that the bearings that operate the water pump assembly are wearing out. Once the bearings fail inside the water pump, it means the unit cannot be repaired and will need to be replaced entirely.

If you notice there is a loud whining sound coming from the front of your motor that increases in volume as you accelerate, contact a mechanic as soon as possible to inspect your vehicle.

4. Engine is Overheating

When the water pump fails completely, it will not be able to circulate coolant through the engine block. This results in an overheating situation and if not repaired or replaced quickly, can cause additional engine damage like cracked cylinder heads, pushed head gaskets, or burnt pistons. If you notice the engine temperature gauge runs hot on a frequent basis, it's more likely than not a problem with the water pump. You should contact a mechanic to inspect this problem and replace the water pump if needed.

5. Steam Coming from your Radiator

Finally, if you notice steam is coming from the front of your motor as you drive or come to a stop, it is an instant sign of an overheated engine. As discussed above, an engine will maintain a consistent temperature when the water pump works correctly and circulates water to a functioning radiator. If you notice steam coming from the front of your motor, you should pull over to a safe area and contact a mechanic as soon as possible. It's never a good idea to drive an overheating engine, so if you have to contact a tow truck to get the car home, this could save you significant money in the short and long term – it's going to be less expensive than replacing the engine entirely.

Anytime you notice any of these warning signs, contact a local ASE certified mechanic so they can repair or replace the water pump and get your car back onto the roads without delay.


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