The Signs of a Failing Fuel Pump and What to Do About It

A well-functioning fuel pump is crucial to the overall performance of your vehicle. It’s responsible for sending fuel from the gas tank to the engine, ensuring your car runs smoothly. When the fuel pump starts to fail, your engine's performance suffers, and if left unchecked, it can lead to more serious (and costly) damage. Recognizing the early warning signs of a failing fuel pump and knowing what to do about it can save you from getting stranded on the side of the road.

What Does a Fuel Pump Do?

Before diving into the signs of failure, it’s important to understand the role of the fuel pump in your car. The fuel pump’s primary job is to move gasoline from your car’s fuel tank to the engine’s fuel injectors, where it can be combined with air to produce combustion. The fuel pump operates under high pressure to ensure the fuel is delivered at a consistent rate, allowing the engine to run efficiently.

There are two main types of fuel pumps:

1. Mechanical Fuel Pumps
   Typically found in older vehicles, these pumps are driven by the engine and provide fuel pressure based on the engine's speed.
2. Electric Fuel Pumps
   Modern cars usually use electric fuel pumps, which are mounted inside the gas tank and provide a steady flow of fuel regardless of engine speed.

Signs of a Failing Fuel Pump

So, now that you know the crucial role a fuel pump plays in the overall operation of your vehicle, let's take a look at some of the most common signs that a fuel pump may be failing.

Engine Sputtering at High Speeds

One of the earliest signs of a failing fuel pump is engine sputtering when driving at high speeds. As you accelerate, your engine requires a steady supply of fuel to maintain power. If the fuel pump is not functioning properly, it may struggle to deliver enough fuel to the engine, causing it to sputter or hesitate.

This sputtering often occurs at higher speeds because the engine demands more fuel. If you notice this symptom while driving on the highway, it’s a clear indication that your fuel pump may be weakening and needs attention.

Difficulty Starting the Car

If your car is struggling to start, a failing fuel pump could be to blame. When you turn the key in the ignition, the fuel pump should immediately engage to send fuel to the engine. However, if the pump is worn out, it may take longer to build up enough pressure to start the car, or it may fail altogether.

In cases of a severely failing fuel pump, the car may crank but not start at all, as the engine isn’t receiving the fuel it needs to ignite.

Loss of Power Under Strain

Another common sign of a failing fuel pump is a noticeable loss of power when your car is under strain. This can happen when you’re driving uphill, towing a heavy load, or accelerating rapidly. During these moments, the engine requires more fuel, and a weak fuel pump may not be able to deliver enough, leading to a sudden drop in power.

You may feel the car struggle or jerk as you attempt to accelerate, and the engine may even stall in severe cases. If you frequently experience a loss of power under these conditions, it’s worth having the fuel pump checked.

Engine Stalling at Idle

A faulty fuel pump can also cause the engine to stall while the car is idling. At idle, your engine requires only a small amount of fuel to keep running, but if the fuel pump is failing, it may not be able to maintain consistent pressure, leading to intermittent stalling.

This symptom is particularly dangerous because it can occur unexpectedly, such as when you're waiting at a traffic light or stop sign. If your car frequently stalls while idling, it could indicate that the fuel pump isn’t supplying fuel consistently.

Surging or Jerking Movements

A failing fuel pump can also cause your vehicle to experience surges, where it suddenly accelerates or jerks forward without any input from you. This is because a faulty fuel pump may send irregular bursts of fuel to the engine, causing these erratic movements.

While surging or jerking can occur at any speed, it’s most noticeable during acceleration. These unexpected movements can make driving dangerous and indicate that your fuel pump needs immediate attention.

Decreased Fuel Efficiency

A faulty fuel pump can affect your car’s fuel efficiency. If the pump is delivering too much or too little fuel to the engine, it can throw off the optimal air-fuel mixture, causing your engine to burn more fuel than necessary. As a result, you may find yourself visiting the gas station more frequently despite not changing your driving habits.

If you’ve noticed a significant drop in your car’s fuel economy, it’s a good idea to have the fuel pump inspected to see if it’s contributing to the problem.

Unusual Noises from the Fuel Tank

A healthy fuel pump typically operates quietly in the background. However, as the pump begins to wear out, it may produce unusual noises, such as whining or buzzing sounds coming from the fuel tank. These sounds are a sign that the pump is struggling to maintain consistent fuel pressure.

If you hear these noises while the engine is running, especially when the tank is full, it’s a strong indicator that the fuel pump is nearing failure.

Check Engine Light

In some cases, a failing fuel pump can trigger the check engine light on your dashboard. This happens because modern cars are equipped with sensors that monitor the fuel system. If the sensors detect irregular fuel pressure or delivery, they will alert the onboard computer, which will then illuminate the check engine light.

While the check engine light can be triggered by a variety of issues, it’s worth having the fuel system, including the pump, inspected if this light comes on in conjunction with any of the other symptoms mentioned.

What Causes Fuel Pump Failure?

Fuel pumps can fail for several reasons, and understanding the potential causes can help you prevent future problems.

• Contaminated Fuel: Dirt, debris, or rust in your fuel tank can clog the fuel pump and cause it to wear out prematurely. This is why it’s important to use high-quality fuel and replace your fuel filter regularly.
• Running on Low Fuel: Consistently running your vehicle with a near-empty gas tank can cause the fuel pump to overheat, as it relies on fuel to stay cool. Keeping your gas tank at least a quarter full can help prevent unnecessary stress on the pump.
• Electrical Issues: A malfunction in the fuel pump’s electrical system, such as a blown fuse or a damaged relay, can prevent the pump from working properly.
• Wear & Tear: Like any mechanical component, fuel pumps will eventually wear out due to age and mileage. Most fuel pumps are designed to last between 100,000 and 150,000 miles, but this can vary depending on your driving habits and maintenance routine.

What to Do If You Suspect a Failing Fuel Pump

If you notice any of the symptoms of a failing fuel pump, it’s important to act quickly to prevent further damage to your vehicle. Here are the steps you should take:

1. Get a professional diagnosis.
   The first step is to have your vehicle inspected by a certified mechanic, like the ASE-certified team at Metro Motor. We use specialized diagnostic tools to check the fuel system, measure fuel pressure, and identify whether the fuel pump is the root cause of the problem.
2. Replace the fuel pump if necessary.
   If the fuel pump is confirmed to be failing, it will need to be replaced. While fuel pump replacement can be a costly repair, it's essential to prevent further damage to your engine. At Metro Motor, our experienced technicians can replace your fuel pump with high-quality, reliable parts to get your vehicle back on the road quickly.
3. Prevent future issues.
   After replacing the fuel pump, take steps to maintain the health of your fuel system. Use high-quality fuel, replace your fuel filter according to your vehicle’s maintenance schedule, and avoid driving on an empty tank.

Your vehicle’s fuel pump is a critical component in ensuring smooth engine performance. Recognizing the signs of a failing fuel pump early can save you from more serious issues down the road. From engine sputtering and stalling to unusual noises and decreased fuel efficiency, these symptoms are clear indicators that your fuel pump may be failing. If you experience any of these issues, it’s crucial to have your car inspected and repaired by a professional.

At Metro Motor, we specialize in diagnosing and repairing fuel system issues, including fuel pump failure. Our skilled technicians can provide you with prompt and accurate service, ensuring your car runs smoothly for miles to come. Don’t ignore the warning signs – schedule a fuel system inspection with Metro Motor today.