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How To Know If Fuel Pump Is Bad

How To Know If Fuel Pump Is Bad: Top 5 Warning Signs

One of the most essential components in the engine of your vehicle is the fuel pump. The fuel pump serves the important purpose of allowing the car to be powered. It is responsible for pumping the gasoline from the gas tank to the engine of your vehicle. But knowing if the fuel pump is bad could save you plenty of trouble.

The most noticeable sign that your fuel pump is going bad is that your engine will stutter. The stutter can be felt when you are pulling away, but it is most noticeable when you reach top speeds on the highway. Additionally, your vehicle might even cut out eventually. This could be due to various reasons, but it is often a symptom your fuel pump has gone bad.

To help you better understand some of the possible signs that your fuel pump has gone bad, we have focused on some of the important signs. However, to understand why something goes wrong with the fuel pump, you might need to understand how it works.

How Does The Fuel Pump Work?

an engine
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The main component in your fuel pump is the DC motor that powers the component. The fuel pump activates the motor when you art the vehicle and this enables the pump to draw fuel from the gas tank and direct it to the engine.

To accomplish this engineering feat, the pump will withdraw the fuel from the gas tank utilizing the fuel line or hose. This will eventually transfer the fuel into the fuel rail, where the injectors take over. The main purpose of the fuel injectors is the inject the fuel into the cylinder where it comes into contact with spark plugs to create combustion.

Once the fuel reaches the combustion chamber, it is ignited and this is what powers your vehicle in a forward motion when you press the gas pedal.

How To Know If Your Fuel Pump Is Bad (5 Signs)

If this process does not happen, you might have something wrong with the fuel pump. There could be various reasons why your fuel pump is not working and a qualified mechanic can assist you in finding the fault. We have identified the most common signs to look out for if you notice the fuel pump acting up:

1.      Sputtering or Stuttering Engine

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One of the most common signs will be that your engine does not act as it should. You might notice stuttering in the vehicle, which is due to inadequate levels of fuel being available for combustion. If the fuel pump cannot draw enough fuel into the combustion chamber, the sparkplugs cannot ignite the fuel to power your vehicle.

Keep in mind that faulty spark plugs might have a similar effect on your vehicle. However, your fuel pump might be the main cause.

We should mention that your engine might even surge which is the opposite of stuttering. This could be due to a faulty fuel pump that suddenly pumps too much fuel into the combustion chamber. However, bad fuel sensors might also be at fault.

2.      Loss Of Power (Suddenly Or Gradually)

interior dash
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While various factors like engine wear and damaged components could cause a loss of power, many people have reported losing power on the top end when the fuel pump is bad. Since the fuel pump is responsible for constantly pumping fuel, a slight halt in fuel pumping could cause a significant drop in power.

The issue is most noticeable when you are driving uphill or in situations when your vehicle relies most on power.

3.      Low Gas Mileage

fuel levels
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Another common problem detected with a faulty fuel pump is bad fuel efficiency. Your fuel pump might pump more fuel than the vehicle needs and the combustion chamber would continue to ignite the fuel. While all signs of bad fuel consumption might not be related to a faulty fuel pump, it is worth considering if you notice it.

4.      Rattling Or Whining Fuel Tank

engine block
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Even though the problem could be centralized to your fuel pump, one of the major signs of a failing fuel pump is whining or an unnatural sound coming from the fuel tank. While the fuel pump does make a natural quiet sound when operating, a whining or rattling sound could be an indication that something is wrong.

If components break off from the fuel tank, these could end up in the tank. Additionally, the fuel tank could be contaminated by leaks in the fuel lines, which cause damage.

5.      Dead Engine

stop start button in car
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Finally, you might wake up one morning and try to start your engine, only to find that the engine does not respond. A dead engine is often associated with inadequate levels of fuel being pumped into the combustion chamber. Keep in mind that there are various other reasons for this to happen as well.

Another possible sign related to the dead engine is that your vehicle randomly stalls. The ICE could seize, and you might be stuck in traffic with a damaged engine.


How Long Does A Fuel Pump Last?

As our mind would have it, you might be constantly thinking of your fuel pump now. However, you can rest assured that the fuel pump is not a flimsy component. Ideally, your fuel pump should last around 100,000 miles. However, factors like maintenance and using good quality fuel could lengthen or reduce the life of the fuel pump.

How Much Does It Cost To Replace A Fuel Pump?

While components like the clutch and engine could cost you upward of $1,000 to replace, the fuel pump is not the most expensive component to replace. Bear in mind that it is dependent on the vehicle your drive as well. However, the average cost for a fuel pump replacement would run between $200 and $1,000. High-end vehicles tend to be more expensive in terms of fuel pump replacement, and labor costs will vary depending on the mechanic you choose.


An avid car enthusiast, I love spending time researching new cars and seeing how technology improves each year. With a passion for cars, I often find problems with certain vehicles and believe these should be addressed to ensure everyone can have a happy driving experience. I spend hours on the road each year and having driven numerous cars, I have encountered some basic and unique problems. I love sharing my knowledge and experience with you to help you prevent and even deal with some of these issues before they become fatal!!!

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