7 Signs of a Bad Water Pump + Cost to Fix

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signs of a bad water pump

A while back, my car’s engine was heating up. I checked with almost all common causes of engine overheating, including thermostat valve failure, radiator issues, coolant leak, defective pressure cap, problems with timing belt and hose but no luck.

At last, I consulted with my mechanic in this regard and told him the whole story. He said did you check the water pump? Was it functioning correctly? I suddenly realized he was right; I should have checked the water pump as well.

A faulty water pump was the actual reason causing my car’s engine to heat up.

A water pump is the driving force of the cooling system. It can compromise the working of your entire vehicle.

What is a Water Pump?

water pump

The function of a water pump is to draw coolant from your car’s radiator and then circulate coolant to the entire engine block. The purpose of pumping this coolant into the engine is to carry out the heat produced as a by-product of the engine cycle.

If this heat is not removed, it can cause catastrophic damage to your car’s engine. The water pump plays a vital role in keeping the engine’s temperature under check.

A water pump is nothing more than a simple pump in terms of construction. It has an opening, and it has an outlet. The functioning parts are the rotors that are connected to a driveshaft. This driveshaft draws power from the engine.

The rotating shaft causes the impeller blades to move as well. This increases the pressure of the coolant and keeps it circulating around the engine.

Where is Water Pump Located?

The water pump is located at the front of the engine. It is one of the easiest components of the car to spot. If you can find the timing belt, serpentine belt, or timing chain (which are all very easy to locate obviously), the water pump will be somewhere around.

Since the water pump is powered by one of these belts, there is a pulley that is chain or belt-driven on one end of the water pump. The water pump directly draws power from the engine of your car.

Common Causes of Water Pump Failure

Like any other pump, a water pump is a simple mechanical device that wears out after some time. Two main things that can cause water pump failure are:

Worn Bearing

The impeller blades of the pump are moving on a shaft. Bearings hold the ends of this shaft. These ball bearings can wear out after a certain period. This is the most common cause of failure in water pumps.

Belt Tensioner

As mentioned above, the water pump pulley is driven with a timing belt or serpentine belt.

These belts often use a tensioner to keep the tension up to optimum levels so that the belt does not break or come off the pulley. At times these belts or tensioners wear out, and the water pump fails.

Symptoms of a Faulty Water Pump

Following are the common symptoms of a failing water pump:

  1. Overheated Engine
  2. Coolant Leaks
  3. Whining Sound
  4. Rusting or Deposits
  5. White Smoke From Radiator
  6. Loose Timing Belt
  7. Uneven Engine Temperature

Let us take a closer look at the symptoms of a failed water pump:

Overheated Engine

Overheating of the engine is the first and foremost sign of a failed water pump. Since the primary function of a water pump is to circulate the coolant in water jackets around the engine.

This way it carries away the residual heat of the engine, keeping it from any permanent damage. When water pumps are not working fine, they tend to increase the engine’s average temperature.

If the needle of the temperature gauge on your car’s dashboard crosses the halfway mark, it is a clear indication that something has gone wrong with the coolant system of your vehicle.

Coolant Leaks

If the water pump has gone bad, it can malfunction in two ways. One, it will not circulate coolant around the engine, or it can also pump too much coolant. This might form small holes in rubber hoses or cause leakage around connections.

Coolant leaks can occur in any case. If you see a green fluid on the floor of your parking garage, then it is a clear sign of coolant leakage. Or if the coolant levels in your car are often low, then it is leaking from someplace.

In either case, you need to check for a bad water pump.

Whining Sound

There are multiple rotary components of a pump. If any of these components are faulty or improperly installed, it can make certain noise.

A pulley is connected at the end of the drive shaft of the water pump. If the pulley has become loose, it can give whining sounds. If the pump’s impellers are loose, they can also give squealing noise.

Rusting or Deposits

Coolant fluid is part coolant and part water. Since most pump parts are made up of metal, they can easily catch rust. If the rotors or impellers catch rust, they will not rotate properly.

Deposits and rust will hinder the rotation of the impeller shaft. It can also disturb the center of rotation of the driveshaft that will in turn damage the bearings, belts, and chains.

White Smoke From Radiator

A bad water pump can overheat the engine of your car. Overheating of the engine can cause a lot of trouble for you. Since coolant is in liquid form and overheating of the engine will boil it.

This boiling coolant when reaches the leakage points it may escape through these tiny holes in the form of white fumes. Hence, if you notice white smoke coming out of the front part of the engine, you can be sure that something is wrong with your car’s cooling system.

You need to check all coolant system components and see if the water pump has gone bad.

Loose Timing Belt

The timing belt is one of the most critical components of the engine. It controls the timing of valve opening and closing. You can get a loose timing belt if the water pump has gone bad.

A loose timing belt can harm your engine in a number of ways. It can compromise the entire engine cycle. Improper combustion can lead to issues related to the engine. This can also cause the poor performance of your car.

A loose timing belt will not only reduce the output of your engine but will also limit its efficiency.

A loose timing belt can be easily spotted. If you have a bad timing belt, you will hear a squealing noise coming out of the engine.

Uneven Engine Temperature

If the temperature gauge on your car’s dashboard shows a different temperature at one moment and a different temperature at the other moment, then it might be due to a bad water pump.

A bad water pump can pump too much coolant in your engine that will cause it to cool down. It can also under-deliver the coolant that can cause it to overheat.

Either way, you will see a fluctuating temperature gauge.

Water Pump Replacement Cost

If you plan to get your water pump replaced, it can cost you somewhere between $350 and $800. The cost of the water pump itself is only $100 to $200 depending upon the make and model of your car.

The labor cost represents the remaining part of the total cost. Removing the old pump and fitting the new one is not a big problem. You just place the water pump on the mounting surface and fasten the bolts.

But the main issue is the setting of timing and serpentine belt. Mechanics charge between $200 and $500 for a simple repair that has to do with a timing belt.


A water pump is the main driving force behind a car’s coolant system. If it goes bad, the coolant will not move through the engine and its proper functioning will be compromised.

The major signs of a bad water pump are coolant leaks and overheating of the engine. Which can cause cracked cylinder heads, burnt pistons, or complete engine failure.

In addition to this if you see steam coming from under the hood, check engine light, squealing noise due to loose pulley or loose belt, then you probably need a new water pump.

If a vehicle’s water pump fails it can stop the entire engine. As coolant running through water jackets of the engine ensures its smooth functioning.

You should not take warning signs of a bad water pump lightly and replace a defective water pump as soon as possible.

Frequently Asked Questions

How long can you drive with a bad water pump?

Driving with a bad water pump is not recommended for more than 100 miles. It is a very critical component of the cooling system of a car. If it is not working properly, the entire vehicle comes to a halt.

If you continue driving with a bad water pump, this can hurt other parts of your car. You can get a blown head gasket or a seized engine due to this issue.

What is the average lifespan of a water pump?

The average lifespan of a water pump is 60,000 miles to 80,000 miles. But due to the issues in associated parts, its life can be reduced. Like problems with water pump pulley or loose accessory belt. You should watch out for these issues to increase the life expectancy of your water pump.

Can you replace the water pump yourself?

No, you cannot replace the water pump yourself. It is not very difficult to get to the water pump. You just need to remove a few parts of the engine and you get to it. In the same way, it is not that difficult to install a new pump.

The main problem while removing and installing a new pump is fastening the timing belt and serpentine belt.

Only a professional mechanic can deal with these parts. If you think you have enough expertise to deal with it, you can go ahead.

What other problems can cause coolant leaks?

Like the failure of a water pump, many other issues can cause a coolant leak in your car.

If you have a problem with the expansion tank, there is a hole in the radiator, the radiator cap is defective, the head gasket is blown, or you have loose connections in the cooling system, all these problems can cause a coolant leak.

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