Last Updated on March 01, 2020
A water pump drives and safeguards the coolant throughout the components of the engine to ensure the cooling system releases the heat that the engine generates. How does a water pump work in a car is a question that most vehicle owners may not be able to answer correctly? One could correctly argue that the main function of the water pump is to help the engine reach optimum operating temperature and maintain it. However, it helps to know exactly how the water pump works.
It will be quite difficult to jump straight to the workings of a water pump without looking at its components and what they do individually. It is important that we understand all the components of a water pump and how they function to achieve the desired cooling effect. Then we will look at the different types of water pumps and the difference between the types.
Basic components of a water pump
From the name, the housing is what encases and protects the water pump from eternal damage. Most are usually made of aluminum or cast-iron except for modern designs made of stamped-steel. The housing includes what is referred to as a weep hole which allows leaking coolant to escape from a faulty seal. The housing is therefore key to ensure the coolant does not get rapped in the bearing assembly and cause permanent damage to the engine. The weep hole is located between the pump seal and the hub.
The impeller is connected to the shaft’s bottom inside the housing. The main function of the impeller is to distribute coolant through spinning. The impeller’s rate of spinning is determined by the vehicle’s RPM. It is usually made of either plastic or metal. Metal impellers tend to last longer than plastic impellers and most manufactures prefer using them when building water pumps.
The bearing is a mechanical support that enables the shaft to move continuously in a stable position. The shaft rides against the bearing with a hub connected on top and impeller at the bottom.
Pulley or hub
This is essentially the source of power for the impeller. It, therefore, facilitates the rotation of the impeller and is considered to be very vital. The V-belt, timing belt, and engine’s serpentine are also connected to the hub or pulley.
The seal is important in protecting the bearing from contaminates and leaking coolant by going around the shaft. Once the seal fails, then you will be able to observe leaking coolant from the vehicle when the engine is running.
The mounting gasket performs one primary simple function; sealing the engine from the water pump.
Types of water pumps
There are essentially two types of water pumps depending on your car’s engine concept. a water pump either has electric or mechanical drives.
Those with mechanical drive
Water pumps that have the mechanical drives are integrated using either a V-ribbed belt or toothed belt drive. The speed of the water pump and that of the engine have a fixed link due to the transmission ratio generated between the water pump impeller and the crankshaft drive.
Those with electric drive
Contrary to the mechanical drive water pumps, those with electric drives do not depend on the speed of the engine. Their performance is dictated by the current cooling requirement of the engine. In short, this type of water pumps can achieve an operating temperature very fast. They are also considered to be more efficient because they reduce fuel consumption.
Workings of a water pump
A typical water pump will move about seven thousand five hundred gallons of coolant every hour. The water pump is also able to recirculate coolant throughout the entire components of the engine more than twenty times per minute. Did you know that at this speed your water pump could empty an entire pool in just over an hour? I am betting you did not know how powerful the water sump pump is until right about now. It is also important to note that your water pump will work in relation to your engine. This means that it pumps less at slower speeds and more at higher speeds.
When your engine speed increase, the amount of heat produced also increases and the water pump is expected to counter the sudden increase. The impeller will, therefore, needed to increase the rotational speed to provide the expected coolant flow. It is therefore important to inspect the coolant, water pump, and belt drive system during each car servicing to ensure the cooling system doesn’t fail while traveling because it may just leave you stranded.
The coolant is drawn from the engine block into the water pump and quickly directed to the radiator. In the radiator, the coolant passes through small thin tubes to provide a wider surface area to cool the heated liquids in the engine. This coolant then moves back to the block and engine cylinder head to pull the additional heat that is generated by the engine. This process is continued throughout by the water pump until the engine stops running.
Eventually, your water pump will fail and you will need to replace it as soon as possible to avoid permanently damaging your engine. Remember that car engines are very expensive to replace and will cost you a lot of money. Water pumps, on the other hand, do not cost a lot to replace and the process only takes about an hour or two.
How to identify a faulty water pump
1. Overheated engine
This is the most obvious symptom and the easiest to identify from all the rest. A faulty pump will hinder your engine from cooling down simply because the coolant is not circulating properly throughout your entire engine and its different components. You need to observe the temperature gauge located on the dashboard of your car regularly whenever going out for a drive. The temperature gauge will rise when the engine is overheated and you should easily identify it. Located on the dashboard is also a temperature warning light designed to illuminate once the engine is overheated. The two indicators are hard to miss and you will spot them almost immediately.
A loose belt will cause a buzzing or whining noise coming out of your car’s front area. When the belt circulates it causes the weirs noises you hear. A loose pulley or worn out bearings could be the most probable reason why your belt is loose and needs replacement. It is considered impractical and expensive to repair a water pump’s bearings and therefore it is advisable to simply buy a new one. Repairing the bearings is never a permanent solution and you will find yourself having water pump problems again after a short while. Should the buzzing noise become louder when accelerating then you should see a professional mechanic soon because it might be engine damage.
3. Radiator steam
Another instant indicator of a faulty water pump is steam coming from your vehicles’ front side. Water needs to circulate your radiator and cool it down. A bad water pump will not sufficiently cool your radiator and therefore the water will heat up producing steam that will come out of your car’s front end.do not continue driving your vehicle once you see smoke coming from your vehicle. You could cause irreversible damage o your engine and you will be forced to purchase a new one. Seek help from a professional mechanic at once and have your water pump fixed.
4. Fluid leak
Fluid leaking from your engine while driving is an indicator of a bad water pump. The seal is broken and the coolant leaks out thereby avoiding entering the shafts and causing permanent damage. Remember the fluid only leaks when your engine is running and stops immediately the engine comes to a stop. You will need to take your vehicle for servicing and have the water pump looked at immediately.
5. Bouncing temperature gauge readings
The temperature readings should always remain in a constant normal position while the engine is running. Should you notice sudden shifts from low to high and high to low, then there is a problem with your radiator or water pump.
Cost of replacing water pumps
The cost of replacing your bad water pump will vary depending on the type and make of your vehicle. Normally the price ranges from around 150 dollars to 800 dollars. Ensure, however, that a professional mechanic does the replacement for you to avoid any further damages on your engine.
Many vehicle owners usually take very little consideration of their water pumps. Once you can know how a water pump works in a car, then you can learn to appreciate it and the work it does to keep your engine cool. It is also important to learn the symptoms of a bad water pump so that you can easily identify the problem and fixed it.
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