Is it possible to drive with a bad fuel pump?
Well, it depends on the condition of the pump. You won’t be able to start your car in some cases. Plus, it can be dangerous to drive with a faulty fuel pump.
And what if you have no other option?
Let’s explore how long you can drive with a bad fuel pump, what you may experience, and how to confirm the issue.
This Article Contains:
- How Long Can You Drive with a Bad Fuel Pump?
- 10 Common Bad Fuel Pump Symptoms
- How to Diagnose a Bad Fuel Pump (+Prevention Tips)
- 4 FAQs about Fuel Pumps
How Long Can You Drive with a Bad Fuel Pump?
How long you can drive with a bad fuel pump depends on whether the pump has failed.
If it’s bad but running, you could drive for up to 30 minutes before it fails. You mostly won’t be able to start the car when it fails.
However, driving with a bad fuel pump is inadvisable. It could lead to poor fuel efficiency, stalling, engine damage, or even fires. That’s why it’s best to call a tow or have a mobile mechanic resolve the issue.
But what if you have no other choice but to keep driving?
If you must drive and your car is starting, don’t speed up and make sure your next stop is to a mechanic. Since your engine will face fuel starvation, accelerating or driving unnecessarily will overheat and damage the engine.
However, if there’s also a fuel leak, pull over safely, turn the engine off, and stay a safe distance away from your car while waiting for assistance.
Next, let’s explore common symptoms of a failing fuel pump.
10 Common Bad Fuel Pump Symptoms
If you have a faulty fuel pump, you’ll notice signs like:
1. No Sound When Turning on the Ignition
When you turn on the ignition, you should hear the ‘whirr’ of the fuel pump engaging.
However, if you start the car but can’t hear the whirring sound, you might need a fuel pump replacement.
2. Starting Issues
Since a failing fuel pump won’t send enough fuel to the engine, you’ll face difficulties starting your car. And even if you get it started, you might experience frequent stalling and misfires.
3. Lit Check Engine Light
A bad pump will cause an air-fuel mixture imbalance, which will trigger the Check Engine Light. This warning light may even activate if your vehicle’s fuel pump has electrical issues, like damaged connections or a bad fuel pump relay.
You may also see an illuminated gas light if you have low fuel or a fuel leak.
4. Noise From the Fuel Tank
Loud whining noises from the fuel tank indicate a fuel pump issue. It happens when a failing fuel pump struggles to deliver fuel to the engine.
5. Power Loss
When you hit the gas pedal, your vehicle’s fuel pump increases the fuel flow to the engine to gain more power.
However, when the pump is bad, your vehicle won’t accelerate smoothly and may lose power due to fuel starvation. These signs could also occur in any conditions that require extra power, like driving up slopes.
6. Sputtering or Jerking
A bad fuel pump may cause the engine to sputter or jerk when driving at a high speed. This happens due to incomplete combustion and is usually followed by power loss.
Sputtering could also indicate spark plug issues.
7. Engine Power Surges
A malfunctioning fuel pump could intermittently send a heavy fuel flow to the vehicle’s engine. In such cases, you’ll experience engine surges — where your vehicle suddenly picks up and drops speed.
8. High Engine Temperatures
A consistently rising temperature gauge could indicate a fuel pump issue. It happens because the overheated fuel pump motor isn’t delivering enough fuel to the engine, causing it to overheat.
9. Reduced Fuel Pressure and Gas Mileage
Typically, a bad fuel pump will cause a drop in fuel pressure since it’s unable to pump fuel. However, you’ll probably notice the above signs before you realize the pressure drop. This drop in fuel pressure can result in an imbalanced air-fuel mixture in the combustion chamber, which leads to poor gas mileage.
10. Failed Emissions Test
A malfunctioning fuel pump delivering too much fuel could make the vehicle’s engine run rich, leading to a failed emissions test.
But how can you confirm fuel pump failure?
Let’s find out.
How to Diagnose a Bad Fuel Pump (+Prevention Tips)
Confirming a bad fuel pump requires special tools and technical knowledge. So, it’s best left to professionals.
Here’s how a mechanic would verify it:
- Read the engine warning light codes with an OBD-II scanner. If it’s a bad fuel pump, they may find codes like:
- P0170: Fuel Trim Malfunction (Bank 1)
- P0087: Fuel Rail/System Pressure Too Low
- P0230: Fuel Pump Primary Circuit Malfunction
- Check the fuel pressure with a fuel pressure gauge. A functional pump will have a fuel pressure of around 4 to 60 psi.
If it’s fuel pump failure, they’ll replace the pump.
Once you get a new pump, you should make sure to:
- Maintain at least a quarter tank fuel level and refill if you see a lit gas light: Driving with a low fuel level will overheat the fuel pump motor and shorten its lifespan. Plus, with low fuel levels, the pump will work harder and wear out faster.
- Use high-quality fuel: Low-quality fuel may contain contaminants that can damage the fuel pump. However, don’t worry about refueling when a truck fills gas station tanks — you won’t get contaminated fuel.
- Follow maintenance schedules: Maintenance helps inspect and replace fuel system components, like the fuel filter and old oil.
Have more questions?
Let’s answer them.
4 FAQs about Fuel Pumps
Here are questions you may have about fuel pumps:
1. What Does a Fuel Pump Do?
Simply put, a fuel pump delivers fuel from your gas tank to your vehicle’s engine.
However, you could have one of two fuel pump types:
- A mechanical fuel pump is present on top of the engine. It creates a vacuum to move gas from the fuel line to the carburetor, which mixes in air before it reaches the combustion chamber. A mechanical fuel pump can be repaired in some cases.
- A modern vehicle may have an electric fuel pump inside the gas tank. These use a fuel injector to supply fuel to the engine. An electric fuel pump must be replaced if it’s faulty.
2. How Long Does a Fuel Pump Last?
Fuel pumps are made to last up to 100,000 miles.
However, this depends on regular maintenance and driving habits (driving with low fuel).
3. What Causes a Bad Fuel Pump?
Your fuel pump could go bad due to:
- Normal wear and tear over time
- Impurities like dirt and water in the fuel
- Bad or clogged fuel filter
Following your maintenance schedule can help you stay ahead of these issues.
4. How Much Does it Cost to Replace a Bad Fuel Pump?
A fuel pump replacement can cost between $200 and $600, depending on your car’s make and mechanic’s labor charge.
However, avoiding the replacement could lead to costly engine repair.
Fix a Bad Fuel Pump without Leaving Home
Driving with a bad fuel pump is risky. You could stall on a highway or your engine could catch a fire.
That’s why it’s best to call a mobile mechanic like AutoNation Mobile Service.
We’re a mobile auto repair and maintenance service offering upfront pricing and a 12-month, 12,000-mile warranty on repairs.
Contact us to get fuel system or engine repair services right in your driveway.