As a driver, you should be ready for unexpected failure of any part of your car’s component. They are built to last long but cannot last forever. A time will come when they will fail and you’ll need to replace them.
The car’s fuel pump is responsible for delivering fuel from the tank to the engine. It is built to last thousands of miles but can still fail. So, how long can you drive with a bad fuel pump?
You should be able to drive for a few miles with a bad fuel pump provided the pump has not failed completely. If the pump has failed completely and is unable to deliver fuel from the tank to the engine, then you will not be able to drive with the bad pump.
How Long Can You Drive With a Bad Fuel Pump?
How long you can drive with a bad fuel pump depends on how badly the fuel pump is damaged.
You can still be able to drive a few miles with a bad fuel pump if it has not failed completely. However, if it has failed completely and is not able to deliver fuel from the gas tank to the engine, then the car will not even start, not to talk of moving.
Let me use my failed fuel pump experience as an example to explain this so you can understand it better.
I’ve had a bad fuel pump issue with my two cars. First, it was in my 2003 Peugeot 307 SW and the second was in my Lexus IS350 which I currently drive.
When I had the fuel pump issue on my Peugeot 307, It was unbelievable to me because I used the car the previous day and parked it when I came back from work.
As I wanted to use the car the next day to go to work, it refused to start. I tried and tried. It could not start. I had to go to work without it to avoid running late.
When I came back that same day, I had already bought a replecement pump on the road incase it was not a fuse problem. So, after replacing the pump, the car started with ease.
The fuel pump had damaged to the point that it could no longer deliver fuel to the engine, hence why the car refused to start.
However, when I had a fuel pump issue in my Lexus IS350, I was on a journey. It was 7 hours inter-state journey. The pump got spoilt in the middle of the journey but I was still able to drive the car to where I had the pump replaced.
On that faithful day, I was on a journey when I was pulled over by the police officer. After the interaction with the police officer, I started my car, put it in drive, and the car refused to accelerate.
The acceleration was not working. I floored the acceleration pedal and felt nothing but the car was moving. The police officer noticed what was happening and told me not to worry since I was almost close to the city where I could fix whatever problem it had.
Moreover, the car was still moving, the only problem was the acceleration. It was just rolling. The luck I had was that there was no hill before the city. Just flat roads.
When I got to the city, I drove the car to an auto shop where the fuel pump was replaced with another one and the acceleration started working.
So, from my experience, I can confidently tell you that how long to drive with a bad fuel pump depends on how bad the pump is.
In my Peugeot 307, the car could not start because the pump had gone completely bad, but in the Lexus IS350, the car was still driving but could not show its V6, 311 horsepower because the fuel pump was not working as it should.
The Risks of Driving with a Bad Fuel Pump
Here are the risks of driving with a bad fuel pump:
1. You Engine May Stall and Leave You Stranded
One of the most immediate risks of driving with a failing fuel pump is the chances for engine stalling or complete failure.
A malfunctioning fuel pump may struggle to maintain consistent fuel pressure, causing the engine to sputter, hesitate, or stall unexpectedly, leaving you stranded on the side of the road, especially if the failure occurs in a remote location with threats.
The failure will expose you to safety risks and necessitate assistance from roadside services. Something you could have avoided if you’d replaced the pump when you first got the sign of its failure.
2. Loss of Power and Performance
If your fuel pump is failing, it can result in a noticeable loss of engine power and performance. Just like what happened to me when my Lexus IS350 fuel pump went out in the middle of the road.
The engine will struggle to accelerate, climb hills, or maintain speed, diminishing the vehicle’s overall drivability and responsiveness.
This not only affects the vehicle’s performance but also compromises safety, especially in situations that require swift acceleration or maneuvering.
3. Engine Damage and Component Wear
Driving with a bad fuel pump can lead to detrimental effects on engine components.
When your fuel pump goes bad, it will cause inadequate fuel delivery to the engine which can disrupt the air-fuel ratio, causing incomplete combustion and increasing the likelihood of engine misfires, overheating, and damage to components such as spark plugs, catalytic converters, and oxygen sensors.
Over time, this can result in costly repairs and premature wear of important engine components.
4. Fuel Contamination and System Damage
A failing fuel pump may introduce contaminants into the fuel system, compromising fuel quality and integrity.
For example, contaminants such as dirt, debris, and rust particles can infiltrate the fuel lines, injectors, and filters, leading to clogs, blockages, and system damage.
It can also aid in component wear and corrosion, increasing fuel delivery issues and causing more performance problems.
5. Increased Risk of Engine Overheating
Inefficient fuel delivery caused by a failing fuel pump can lead to irregular engine combustion and increased exhaust temperatures, which can contribute to engine overheating, especially during prolonged periods of driving or heavy load conditions.
Engine overheating poses serious risks to engine health and can result in irreversible damage if not fixed immediately, leading to costly repairs or engine replacement.
I was lucky not to experience overheating the day my Lexus fuel pump went out but it was because I drove less than 15 kilmometer before getting to where the pump was replaced.
6. Reduced Fuel Efficiency and Increased Operating Costs
A bad fuel pump can affect fuel efficiency and increase fuel consumption.
Since inadequate fuel delivery results in incomplete combustion and inefficient engine operation, it can lead to higher fuel consumption and reduced mileage per gallon.
This not only increases operating costs for drivers but also contributes to environmental pollution and carbon emissions.
Nevertheless, the most dangerous risk of driving with a bad fuel pump is the ability to safety threats and accidents.
Sudden engine stalling or loss of power can affect vehicle control and stability, especially at high speeds or in challenging driving conditions, which increases the risk of accidents, collisions, and injury to drivers, passengers, and other road users.
Therefore, I would not recommend you continue driving your car with a bad fuel pump. Have it replaced immediately you get the signs of damage so you can continue enjoying your car as well as driving.
Can a Fuel Pump Be Bad and Still Work?
Yes, a fuel pump can show signs of being bad or failing while still functioning to some extent. This phenomenon is often referred to as a “weak” or “failing” fuel pump.
In such cases, the fuel pump may still deliver fuel from the gas tank to the engine, but its performance is compromised, leading to various symptoms and issues, just like it happened to me in my Lexus IS350.
The fuel pump was bad but was still working. At least, I was able to drive the car to where the pump was replaced. If it has failed completely, the car would not even start.
One common indication of a failing fuel pump is a reduction in fuel pressure. While the pump may still generate enough pressure to deliver fuel to the engine, it may fall short of the manufacturer’s specifications.
This can result in engine performance issues such as hesitation, rough idling, and poor acceleration, even though the engine may still run.
A failing fuel pump may exhibit intermittent operation, working inconsistently or erratically. In some instances, the pump may operate properly for a period before experiencing a sudden drop in performance or failure, leading to unpredictable engine behavior, including stalling, surging, or difficulty starting.
Furthermore, as a fuel pump deteriorates, it may produce unusual noises such as whining, humming, or grinding sounds. These noises indicate mechanical wear or damage within the pump, even if it continues to function.
While the vehicle may still run with a noisy fuel pump, the noise can be a warning sign of impending failure and should be fixed immediately.
Conclusion
How long you can drive with a bad fuel pump depends on how badly the fuel pump has spoilt. You can still be able to drive for a few miles with your bad fuel pump if it has not failed completely.
But, if the pump has failed completely, the car may not start talkless of driving it. You will need to replace the damaged fuel pump before you can continue to drive the car.
