Water Pump

What Does A Water Pump Do In A Car?

Read Time:11 Minute, 8 Second

The water pump in your car is crucial to how efficiently it operates. In fact, if your water pump stops working, your engine could malfunction. You will learn more about the function of a water pump in a car in this article.

What Is A Water Pump For A Car?

The water pump in your car draws moisture from the radiator and pumps it through the engine to the radiator, where the cycle is repeated. No matter the weather, it ensures that the temperature of your motor stays constant.

As it passes through the motor, the water from the radiator warms up. The water pump is required to transfer it back to the radiator so that it can cool down. If not, your engine would become too hot.

History Of The Water Pump

Before internal combustion engines were developed, there were water pumps. These pumps were not developed to reduce water loss because these external combustion engines were made to require the constant addition of new water. The fact that the pump shaft was sealed is largely responsible for these early water pumps’ poor seals.

They typically used a lubricated rope seal, which by design offered an imperfect seal. In addition, while this was not a problem with steam engines, it arose quickly with water-cooled internal combustion engines.

Water-cooled engines were viewed as unreliable in the early decades of the automobile. Although the issue of naturally leaking water pumps was finally fixed around the time of World War II, these factors contributed to the early success of air cooling. Pumps with carbon seals that leaked much less were then being developed at the time.

Basic Components Of A Water Pump


As implied by the name, the housing is what shields the water pump from permanent harm. With the exception of contemporary designs made of stamped steel, the majority are typically made of aluminum or cast iron. Coolant can leak out of the housing through what is known as a weeps hole due to a bad seal.

Therefore, the housing is essential to prevent coolant from wrapping around the bearing assembly and harming the engine permanently. Between the pump seal and the hub is where the vapor hole is.


Within the housing, the impeller is fastened to the shaft’s bottom. The impellers’ primary job is to spin and distribute the coolant. The RPM of the vehicle affects how quickly the impeller spins.

Metal or plastic are typically used in its construction. Most manufacturers prefer to build water pumps with metal impellers because they typically last longer than plastic impellers.

Pulley Or Hub

This serves as the impeller’s main power source. Because of this, it is very significant and makes the impeller rotate more easily. Additionally fastened to the hub or pulley are the engine serpentine, timing belt, and V-belt.


The mechanical support that allows the shaft to move steadily and continuously is known as a bearing. With a hub connected at the top and an impeller connected at the bottom, shafts travel against the bearing.


By going around the shaft, the seal helps to stop coolant leaks and contamination of the bearing. When the seal breaks, you will notice coolant leaking from the car while the engine is running.

Mounting Gasket

The mounting gasket has a single, fundamental purpose: to seal the engine with a water pump.

What Functions A Car Water Pump?

Your car, truck, or SUV’s cooling system relies heavily on its water pump. Its main function is to maintain a coolant flow from the radiator to the engine block of the car to prevent overheating. Even though contemporary water pumps are much more durable, they still have a chance of failing after many years or miles.

Usually, the pump will develop a leak or a bad bearing, which, if left unattended, will seriously harm the car’s engine. The good news is that it is possible to detect potential problems with your water pump in advance.

Water Pump

Is Water Pump Expensive?

Your car’s manufacturer will determine how much it will cost to replace your water pump. Even the specific model can influence the price.

Two different kinds of water pumps are also available: belt-driven and electric.  Normal belt-driven water pumps aren’t too pricey, but electric ones can be expensive, which will obviously increase the cost.  Which kind you have should be described in your owner’s manual.

Another thing to consider is that some water pumps are simpler to access than others. The amount of labor required to access your water pump will depend on how much of your engine needs to be disassembled.

When all of these factors are taken into account, you should be prepared to pay between $400 and $800. The best way to get the best deal is, of course, to shop around and get a few quotes.

A Water Pump’s Operation

In order to keep the coolant flowing through the engine block, cylinder head, hoses, and radiator and maintain the engine’s ideal operating temperature, a water pump is essential to a car’s operation. Typically, a crankshaft pulley or sprocket belt is used to drive it.

The water pump in a car circulates coolant through the various tubes and hoses that make up the cooling system using impeller blades and centrifugal force.

Once the coolant has circulated around the engine, hoses carry it to the radiator, which is typically located at the front of the vehicle. Here, the hot coolant is cooled by air passing over the radiator’s fins. After that, it leaves the radiator and returns to the water pump, where the cycle repeats.

How Does A Car Water Pump Malfunction?

Water pump bearing wear is indicated by a grinding or rumbling sound. The chances are that the seals will also be worn, despite the possibility of replacing the bearings. Since they’re not that expensive, the entire pump is typically replaced for peace of mind.

The failure of the shaft seal or the gasket that sits between the water pump and the engine may be indicated by a coolant leak from the water pump. If it’s the shaft seal, the entire pump will need to be replaced, but if it’s the gasket, the pump can be taken apart, the new gasket installed, and the old pump replaced.

Plastic impellers (fan blades) are sometimes broken in some contemporary water pumps. Vibrations are produced as a result, and the pump eventually breaks down. Although the impeller appears to be in good condition, it may also come unglued from the shaft and cease to function.

What Leads To The Failure Of A Water Pump?

Corrosion in the cooling system or an unbalanced water-pump shaft can cause water pumps to fail before they should. The vibrations caused by a bent fan blade, if there is a mechanical fan mounted on the water pump shaft, can cause the shaft to crack or break. The same damage could be done by a bent pulley.

Signs of a bad Water Pump

  • the front of your car’s center has a coolant leak. In order to keep coolant inside the engine, gaskets and seals must be kept in good condition. If they become dry, cracked, or broken over time, coolant will leak from the water pump.
  • Corrosion of the water pump such as mineral build-up, rust, or contamination identified on the water pump. Using the wrong coolant makes it harder for your car’s engine to cool, which is a common cause of this.
  • Water pump pulley is loose. A loose serpentine belt may cause a high pitched or light thumping noise to be audible from the front of the car. As it moves around, a buzzing pattern or whining echo is produced. Due to dryness, a loose pulley, or worn-out water pump bearings, serpentine belts may break.
  • Engine overheating. The coolant won’t be able to flow through the engine to cool it off if your water pump isn’t working. If your car is overheating, have a technician check it out right away to prevent further damage. Overheating can cause burnt pistons, cracked cylinder heads, and damaged head gaskets.
  • The engine is letting off steam. There shouldn’t be any steam coming from the front of your car unless the temperature is well below zero outside. The presence of steam indicates that the engine is overheating. Pull over, pop the hood to let the engine cool, and dial a tow truck to transport your car to a shop for auto repairs. If you continue to drive with an overheated engine, you run the risk of serious damage and expensive repairs.

What Should I Do If The Water Pump In My Car Leaks?

You have a problem if your water pump is leaking. The severity of the leak determines how serious the problem is.

Water pumps typically leak in two different places: the shaft seal or the water pump gasket. In either case, there’s a problem, and you should change your water pump.

You can pour some stop-leak products directly into your radiator to (possibly) seal or slow the leak. If you choose to go down this path, keep in mind that these products are only a temporary fix and not long-term solutions.

In conclusion, we advise having your water pump replaced by a mechanic if it is leaking. You’ll be grateful to your engine.

How Can I Prolong The Life Of The Water Pump In My Car?

Do not forget that the timing belt frequently drives the pump. In that case, replacing the pump and belt at the same time is required. In fact, some manufacturers advise renewing the pump whenever the belt is changed.

A healthy water pump is simple to maintain: you need to make sure the engine coolant is in good condition and has the correct specification and amount of antifreeze. In addition to acting as a rust inhibitor and preventing small particles from breaking off inside the engine and wearing the pump’s parts, the latter prevents the water from freezing in cold weather.

Replace A Water Pump: Is It Worth It?

A working water pump only requires replacement after 60,000–100,000 miles, so if you’ve had your car for less than 10 years, you might never have to worry about it. Knowing whether the water pump has been replaced is a good idea if you plan to buy a used car.

How Can You Tell When A Water Pump Needs To Be Replaced?

Five Signs You Need a New Water Pump

  • Coolant Leak: The water pump is likely to be to blame for any coolant leaks coming from the front and center.
  • Age doesn’t help the water pump much either when it comes to rust and corrosion.
  • Whining Noises.
  • Overheating Engine.
  • Radiator Steam.

The Water Pump Replacement Process

If your water pump malfunctions, it’s crucial that you replace it with a new one to keep your car running properly. Here are the steps you need to take to properly replace the water pump. Find a water pump that is appropriate for your car as a first step. Your car’s engines should then be turned off.

When you’re about to begin replacing the pump, it makes sure the engine has completely cooled down. The car battery should then be found. Make sure the battery ground has been disconnected in this situation. Installing a drain pan under the engine is the next thing you need to do.

After that, you should empty the cooling systems of their contents. In this situation, you should make sure that cooling compartments are totally drained. Finding the brackets for mounting the alternator is the third thing you must do. The drive belt can then be removed by loosening them.

You can use the socket that is the right size to open them, then lift them away. After that, you should remove any obstructions or clutter from the water pump’s path. After that, you should gain access to it by taking the fan, fan shroud, and engine pulley off. Use the water pumps’ hose after that. Using sockets or a wrench will allow you to complete these.

The engine’s water pump needs to be taken out by loosening the screw. Keep it out of your workspace. Examine and take a look at the engine block. Cleaning it with a cloth is recommended if it needs to be done. If you notice that the water pump gaskets are harmed or brittle, replace them as your fifth action.

After that, you should align the new water pumps and swap them for the old pump. To ensure that you are acting correctly, you should double-check by consulting the manual as you go. The water pump must then be properly bolted to a specific pressure.

Reconnecting the water pump’s hose should come next. You should also replace everything else you took out. In this scenario, you must make sure that belts are correctly adjusted to the vehicle’s recommended tension levels. Refilling the vehicle’s cooling system should be the last thing you do.

In these circumstances, you can upgrade to a better antifreeze or coolant product. Then, you ought to restart your vehicle after plugging the battery back in. Verify that everything is functioning properly by inspecting. This will enable you to properly replace your water pump.

Average Rating

5 Star
4 Star
3 Star
2 Star
1 Star

Leave a Reply

Your email address will not be published.

water pump Previous post 7 Signs Of A Bad Water Pump
Water Pump Next post How Much Does It Cost To Replace A Water Pump?