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pompe à eau d'une voiture

Role of water pump in a car and common problems

Whether it’s during a technical inspection for your vehicle or during a conversation with those around you, you’ve probably heard of the water pump. A crucial element in a combustion engine, it prevents it from overheating by maintaining constant cooling.

And why do you often hear about the water pump? Because it can present anomalies, especially for cars with high mileage. And if these problems are not taken care of quickly, you risk nothing less than breaking your car’s engine.

How about better understanding the role of the water pump in a car, and knowing more about its common problems? This will save you a lot of unpleasant surprises!

Car water pump: role and operation

When we think of cooling for a vehicle, the radiator often comes to mind. However, it is not the only component that prevents the engine from overheating. The water pump is also quite essential! By ensuring the constant circulation of coolant (commonly a mixture of 50% distilled water and 50% antifreeze) between the radiator and the engine, it regulates the temperature of the latter. Since it prevents it from overheating, it contributes to its efficiency, its performance in various driving conditions and its longevity. But why do we fear overheating so much? Because it could cause serious damage to the engine components, or even break it for good.

How the water pump works

And if you’re interested in its exact mechanics, here are some more details on how it works.

  • As soon as the engine is running, the water pump starts up and circulates the coolant.
  • Usually, this pump – small and simple in design – is driven by a belt, and is located at the front of the vehicle. The liquid is therefore cooled at the radiator, and when its temperature is optimal, it is sent back to the engine.
  • Most modern cars have a mechanically driven cooling water pump, via a belt. However, some models have an electrically driven water pump.

Component of your car’s water pump

The water pump is made up of different elements, which also need to be monitored to a certain extent in order to keep it in good condition:

  • The pump body, which houses all the other components.
  • The impeller or propeller, which generates a rotary motion to propel the coolant.
  • The pulley, which connected to the timing belt, drives the rotation of the pump
  • The shaft that connects the impeller to the pulley and transmits the rotary motion.
  • The bearing, which allows the smooth rotation of the shaft.
  • The seal, which prevents liquid leaks.
  • The housing, which is the protective casing containing the propeller.

Unfortunately, this well-oiled machine can have some weaknesses. Fortunately, by paying attention to certain warning signs, these weaknesses can be detected in time.

How to recognize a malfunction of your water pump? By familiarizing yourself with this review of the main symptoms.

When the water pump stops working: common problems

First, the water pump must be changed regularly. On average, this replacement takes place before 150,000 km. Therefore, if you haven’t done it yet, it would be an expense to consider soon!

Among the other signs to watch out for? Noise. As we know, it is never a good omen when an unusual sound emerges from our car. In the case of a defective water pump, you may hear a rather characteristic scratching or whining noise, which increases with acceleration. This is most often caused by a belt that comes loose.

The other sign that will be quite obvious is the flow of coolant. Initially small, the puddles (blue, green, orange or pink, depending on the type of liquid used) will tend to grow larger over time. But don’t wait until this stage to make an appointment!

And since the water pump is supposed to keep your engine from overheating, any signal suggesting a loss of control over your engine’s temperature should alert you. Your best ally? The temperature light that comes on. Of course, it can come on for reasons unrelated to the water pump, but one thing is for sure, you should never ignore it.

To take the diagnosis a little further, these other symptoms should also be considered in the case of a faulty water pump:

  • Dirty coolant;
  • A rusty water pump;
  • A smoking radiator.

Listing the symptoms is a start, but ultimately, what do they indicate? For anything related to leaks, the wear of the seals or other components that ensure sealing will be in the dock. Monitoring their condition regularly will therefore preserve the life of your pump, and prevent water from responding elsewhere in the engine, causing additional damage.

The other recurring problem is called cavitation. It can be the result of insufficient suction pressure, too high a pump rotation speed or design anomalies. As a result? Excessive vibrations, premature wear of components and serious damage to the pump turbine.

Finally, the complication often encountered is the pure and simple blockage of the water pump. If the liquid used is loaded with particles, these can be sucked into the system, end up in the internal elements, and drastically reduce their efficiency, or even render them incapable of functioning.

As you can see, this comprehensive overview of common water pump problems makes it worth spending a little time on the issue of maintaining this part of your car.

Find a trusted mechanic for your water pump…and more!

Of course, a regular inspection at your mechanic will take away a lot of worry. Whether it’s to clean it, detect signs of wear, or to recommend minor car repairs before they turn into costly expenses, you’ll appreciate the investment of time.

You don’t have a regular mechanic or you want to compare the price-quality ratio of the service? Visit the specialists at Trans-Mico Automotive! Overhaul, maintenance, evaluation: they are able to work on a wide range of vehicles, problems and budgets! Established since 1979, their reputation is as reliable as the diagnosis they will make on your car.

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Sources

Vroomly. Pompe à eau : fonctionnement, entretien et prix. [Water pump: operation, maintenance and price]. 2022.
Autoparts24. La pompe à eau est défectueuse? Symptômes et comment la réparer ou la remplacer? [Water Pump Is Faulty? Symptoms and How to Repair or Replace It?]. 2024.
JB Tools. Signes d’une pompe à eau défectueuse : ce que vous devez savoir. [Water Pump: Operation and Common Problems]. 2017.

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