8 Symptoms Of A Bad Water Pump and Replacement Cost

bad water pump symptoms

A water pump plays an important role in any internal combustion engine because,  when the engine is running, it circulates water or coolant in the cooling system of the engine so that the engine can be protected from overheating and the engine temperature can be kept normal and stable. Could.

But sometimes the engine water pump gets damaged, which leads to many problems related to the engine’s cooling system, and in most cases, the engine starts overheating.

In this post, we will learn in detail about the symptoms of a bad water pump so that you will be able to identify it on the basis of these symptoms and save your vehicle’s engine from overheating.

What Is A Water Pump In Engine?

The water pump is a vital component in any internal combustion engine that circulates coolant or antifreeze in the engine’s cooling system. It plays a vital role in maintaining and controlling the optimum operating temperature of the engine.

The engine water pump is driven by a serpentine belt. As the engine starts, the water pump rotates and draws coolant from the radiator and passes it through the engine block and cylinder head to eliminate excess heat generated during combustion.

Symptoms Of A Bad Water Pump

A common symptom of a bad water pump in the engine is engine overheating. Other symptoms may include a rising temperature gauge, leaking coolant, steam coming from the hood, squealing or grinding noises, failure of bearings, or a loose or wobbly pulley.

1. Rising Temperature Gauge


The first and most common symptom of a bad or failing engine water pump while the vehicle is running is a high temperature displayed in the vehicle’s temperature gauge. After the engine is properly warmed up in the temperature gauge, the temperature needle is exactly in the middle.

But when the water pump is bad or failing, the needle in the temperature gauge starts to move up. which indicates a high engine temperature, and in some vehicles, the red overheating light in the digital cluster meter may blink or the light may stay on.

2. AC System Suddenly Shuts Off

ac clutch not engaging

When your vehicle’s engine cooling system fails or the engine water pump is damaged, the vehicle’s engine begins to overheat.

So your vehicle’s AC may stop cooling. This happens because the vehicle engine has a temperature sensor installed in it, and when the engine overheats, this sensor sends a high engine temperature signal to the vehicle’s ECU unit.

The vehicle’s ECU prevents the module from supplying power to the vehicle’s AC system. Due to this, the cooling of the vehicle’s AC suddenly stops permanently, or the cooling from the AC comes intermittently.

3. Leaking Coolant


Whenever the engine water pump of the vehicle is damaged or fails, the coolant cycle then stops in the entire engine block. As a result, the cooling system of the engine is unable to maintain a normal engine temperature, and the engine temperature begins to increase during walking.

Due to the increase in the engine temperature, the engine starts overheating, causing the gas to remove the coolant through the overflow pipe of the system.

Due to which, the engine starts leaking. Therefore, the leakage of coolant is also a sign of a poor water pump or a failed coolant system.

4. Loose Water Pump Axle


The engine water pump is a mechanical device where there is a skin on the outside, on which the serpentine belt moves, and an impeller inside the water pump, which rotates the coolant circle.

The water pump has a small axle shaft between the pump winch and the impeller. On which both of these things revolve. But sometimes, this axle shaft becomes loose due to the breakdown of the axle shaft or the effect of the water pump.

The looseness of the axle of the water pump can be felt by shaking it by hand. This symptom can also be caused by a poor or unsuccessful engine water pump.

5. Engine Overheating Issue


Whenever the water pump of a vehicle is defective or fails, the circulation of the coolant in the engine block stops, due to which the temperature of the running engine starts to exceed the prescribed normal temperature, and in no time the engine starts overheating.

And it can be felt when approaching the engine or touching it with a light hand. All parts of the engine feel hotter than normal when touched with a light hand.

This symptom could also be caused by a bad or failing engine water pump. In some cases, a faint smoke may also be seen coming out from the side of the engine when the engine overheats.

6. Steam Coming From The Radiator Cap

smoke in radiator cap

Whenever the water pump of the vehicle engine is defective or fails, the coolant circulation stops to keep the engine temperature constant. Due to which the coolant in the engine block starts vaporizing when the engine overheats.

And when the engine is overheated, this steam is seen coming out in the form of smoke from the radiator cover or overflow pipe. So smoke coming out of the radiator cap can also be a symptom of a bad or failing engine water pump.

And when the engine is running, this vaporous smoke can appear more consistently at higher altitudes with higher pressure when the radiator cap is opened.

7. Unstable Engine Temperature

The vehicle’s cluster meter is equipped with a temperature gauge to see the temperature of the engine, which shows the temperature of the engine.

However, on some vehicle digital meters, a red light may flash when the engine overheats. But in a simple temperature gauge, the needle shows the range from the starting temperature of the vehicle engine to normal and high temperatures.

Sometimes the water pump of the engine works intermittently. Due to this, sometimes the temperature of the engine starts getting high.

When the water pump starts working, the engine temperature returns to normal. Because of this, fluctuating engine temperatures can also be a symptom of a bad or failing engine water pump.

8. Whining, Buzzing or Squealing Noise

Sometimes an unusual noise starts coming from the water pump of the vehicle. This noise gets louder as the RPM of the engine increases.

There can be many different reasons for this type of pump noise. For example, the serpentine belt running on the pulley of the water pump may be too tight or looser than normal. An improperly stretched serpentine belt can cause a whining, buzzing, or squealing noise from the water pump when the engine is running.

This type of noise can also be caused by a faulty bearing on the axle shaft of the water pump or it can also happen due to the pulley of the water pump breaking or being rubbed with something. These symptoms can also be caused by a bad or failing water pump.

How To Replace Water Pump

Protective Precautions:

  • Be sure to take safety precautions when replacing most water pumps.
  • First, let the engine and coolant of the vehicle cool down. Because if the vehicle goes to the mechanic’s garage, it is possible that the engine coolant temperature will be high due to a failed or bad water pump.
  • Due to this, an excessively hot coolant can cause harm when it touches your body.
  • Never open the coolant bottle cap or radiator cap of a hot engine.
  • Due to the overheating of engine coolant, steam gas is formed in the engine block.
  • Due to this, this gas comes out with high pressure when the radiator cap is opened when the engine is hot.
  • And it gets extremely hot. It can directly harm your eyes or any part of your body.

Replacement Process

  • To replace the water pump, first remove the engine coolant and the parts connected to it.
  • Those parts that are obstructing the flow of water, such as coolant hoses, pipes, a serpentine belt, a timing belt, or a chain
  • Along with this, inspect the parts related to the water pump and other cooling systems of the vehicle.
    If necessary, replace these damaged parts as well.
  • Always replace the thermostat valve, radiator cap, seals, and gaskets whenever you replace the water pump.
  • During the inspection, if the radiator is found to be blocked or damaged, get it flushed or replace it with a new one.
  • Now, fit the new water pump properly with the new gasket and fit all the parts related to the water pump properly.
  • So that the problem of leakage of coolant does not arise.
  • Then add more coolant. and start the engine at the idle position.
  • The coolant level will be low once the engine starts.
  • Because coolant will start going into the engine block, when starting the engine, top up the coolant level again.
  • After this, keep the engine started until it reaches the normal half temperature.
    After that, check for coolant leakage.
  • When everything is normal, test drive the vehicle so that you know that the water pump in the engine is working properly.

Water Pump Replacement Cost

On average, the replacement cost of a normal engine water pump is between $300 and $750. Water pumps in the engine can cost between $90 and $400, and a professional auto mechanic’s labor cost to replace them may be between $210 and $360.

Water pump cost: $90 to $400
Mechanic Labor Cost: $210 to $360
Total Water Pump Replacement Cost: $300 to $760

The cost of replacing the engine of the vehicle’s engine water depends on the makers and models of the vehicle. In addition, the labor fee of the mechanic and its replacement can affect the cost.


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