Most Common Cummins Lift Pump Failure Symptoms with Solutions

Do you know any Cummins lift pump failure symptoms? It would be important to read this article and learn about the kinds of symptoms a lift pump exhibits before you experience that problem.

Lift pumps are used to pump fuel. Your vehicle’s fuel tank is where the lift pump is located.

Lift pumps pump oils from the tank to the injector, which creates a spark that then leads to a burning in the engine.

The lift pump works with a DC motor or Vacuum to pump fuel oils with high pressures to the injector lines.

During are several reasons why you will experience problems with your lift pump pumping fuel oil, which results in your vehicle not starting.

After proper research, we found several Cummins lift pump symptoms that you should be aware of. Moreover, these symptoms apply to all lift pumps. So, let’s get into it.

Common Cummins Lift Pump Failure Symptoms

If you do not know or find out the symptoms of a problem, you cannot find a solution.

Unfortunately, many of the time we don’t receive the right information and as a result, we get stuck in our problems rather than find a solution for them.

The same goes for your lift pump. Before you can reach a solution, you need to know the right symptoms.

There are different signs of a Cummins lift pump system failure. Most of them will indicate that your lift pump system has failed. Below are symptoms to watch out for;

01. The engine won’t start

This is a fundamental symptom that affects everyone. It happens despite having a filled fuel tank and your engine won’t start.

In that case, the problem is likely caused by the lift pump failure, since it cannot pump fuel to the engine and pressurize the piston to function perfectly, so the engine won’t start.

There may be a variety of reasons why your engine is not starting, so in this case, you should make sure that your lift pump is working properly and not the chief cause.

02. The tank requires frequent filling

You should check your lift pump for failure if your fuel oil tank frequently needs to be filled.

Your lift pump would have failed if the system fails to pump the appropriate fuel oil, and also fails to restore the fuel that was not used.

Consequently, you will need to fill up the tank more frequently than the average person.

03. Low Fuel Pressure Rate

As you drive, keep an eye on the amount of fuel your vehicle is consuming and the level of pressure it is producing.

Cummins engines generally perform at 20 to 40 PSI or 15 to 20 PSI for other engines. With PSI means Pressure force per square inch.

As such, if you observe your pressure gauge is falling below the idle rate, even when you accelerate, then you must be experiencing failure with the lift pump.

04. High Temperature of the Vehicle

If you notice that your car temperature is rising and it’s causing your car to stall, don’t wait any longer.

You must be experiencing problems with your lift pump and it can cause a lot of burning. In other words, rising temperatures indicate the lift pump is failing in your vehicle.

It can cause an accident at any time; therefore, you have to ensure that you change it immediately.

05. Vehicle making squeaky noises

When your fuel tank starts making some squeaky kind of noise, it’s a sign that your lift pump is malfunctioning.

Naturally, a normal humming sound can be heard inside the fuel tank when it is functioning properly, but it’s a quiet one.

If you hear any squeaking or whimpering, then you should replace the lift pump. Fuel oil is not being pumped by the lift pump, which is a symptom of a problem with the lift pump.

Therefore, it is of utmost importance to change it immediately or you may suffer severe consequences.

06. Sudden Engine Dying or Vehicle Rippling

Imagine that you’re driving your car, and it suddenly starts jerking and getting halted, forcing you to restart the engine over and over. This is a sign of lift pump failure.

The sudden death of your engine could also be a sign that your lift pump is failing. The engine surges even though the tank is full.

You will need to check the lift pump and replace it if as soon as possible if you notice that the lift pump has failed.

07. A Leak or Crack in the fuel line

In this case, a lift pump failure happens after there’s a leak in the fuel line. You will see fuel oil leaking meaning there are leaks or cracks in your fuel line.

The oil is falling out of the lift pump due to its failure, as the pump isn’t able to pump off the oil. This needs to be corrected right away.

Without it, not only will you waste fuel, but you also won’t be able to run your engine.

Cummins Lift Pump

The injection pump of your car always needs fuel to operate, and it’s the job of a lift pump to provide it. To put it quite simply, a lift pump’s job is to deliver fuel to the injection pump.

Typically, old model diesel vehicles have a small motor lift pump installed either on the fuel rail or in the fuel tank. An electronic control module is used to control the pump.

The system functions such that fuel is forced through the fuel supply line to the filter and onto the high-pressure injection pump by the lift pump.

The fuel doesn’t need to be put under high pressure as this is done by the injection pump.

However, the fuel pressure must be enough to handle the volume needs of the injection pump, which is lubricated by diesel fuel.

There are many different designs of lift pumps, all of which function differently. These fuel pumps can either be electric or mechanical.

Let’s observe the difference between them.

Mechanical Lift Pump

The fuel pressure and volume are fixed in mechanical lift pumps. Old OEM units typically use these.

Electric Lift Pump

The fuel pressure and volume may be adjustable, unlike a mechanical lift pump.

Solutions for Symptoms of Cummins Lift Pump Failure

After listing some Lift Pump failure systems above, we have decided to point out a few solutions that might work if you experience any of those symptoms.


The back of most Cummins lift pumps usually has an electronic solenoid. Here, the solenoid receives an electric charge and releases an actuator which tells it when to close or open.

The pump can malfunction if the solenoid is shorted.


Check your power supply if your solenoid valve does not open or close properly. Furthermore, replace any worn or spoiled seals or membranes if it has a leak.

Check the orifices of the valves for residue as well. Spend some time cleaning the pipes thoroughly until they are clean.

The solenoid can sometimes be damaged from coil burnout or cold due to power running. Then, you’ll need to make sure you have an adequate power supply for distributing heat by ventilation.

Change the coil with something new. However, it should only be used if it’s mounted on the valve.


Fuel lift pumps are linked to gear trains through couplers. Furthermore, it enables the pump to perform the process that draws fuel from the tank.

Any damage or tear to the coupler will disrupt the fuel system’s ability to process a proper suction. Consequently, fuel will be difficult to draw.


Turn off the vehicle. Then, check the coupling insert for wear and tear and look for misalignment problems. A double-cardanic spacer coupling could be used as a replacement.

Coupler failures may be caused by overloading. If this happens, you should disassemble the engine, check the shaft sizes, and adjust them as necessary.

To prevent bolts from backing out, tighten any improperly fit bolts with a liquid hardener.

Occasionally, coupling problems can be caused by torsional vibration. To identify the damage, cut the power to the vehicle and turn it off.

Take the vehicle to the manufacturer to perform vibration analysis on the car to see if the cause of the problem. Make sure all coupling bolts are tight.

Seal Valve

Shaft-driven lift pumps are a common feature of Cummins engines. Pumps are unable to operate at the right setting if the oil seal inside starts leaking.

Seal leaks can be caused by the use of improper additives and ultra-low sulfur fuel.


You can temporarily fix the problem by using an oil stop leak additive first. This will cause the seal to swell and prevent leaks.

Additionally, some leaks can be prevented or reduced by using high mileage motor oil

Crucial Dodge Cummins Lift Pump Symptoms

01. Refilling your tank often

Check your lift pump if you have to refill your vehicle too often. The pump may not be pumping enough fuel, or it may not be restoring the unused fuel.

As a result, you might have to frequently refill your vehicle.

02. Fuel line cracking or leakage

The failure of the lift pump can result in leaks or cracks in the fuel line. When you find oil slightly dripping from the engine, that’s an indication that the lift pump has failed.

03. Hearing unwanted sounds from your vehicle

When you start hearing noise from your vehicle suddenly, that may be a symptom of a faulty lift pump. You might hear a squeaking noise coming from your fuel tank if you pay close attention.

The problem has to do with your lift pump, and you need to find a way to fix it.

04. Engine Splutter during Accelerations

It is not uncommon for fuel lift pumps to fail while a vehicle is on acceleration. During acceleration, however, you will notice jerking/spluttering from the car.

05. Vehicle High Temperature

You need to check your lift pump if you notice a sudden rise in the temperature of your car. The problem may be caused by the oil pump not working properly.

If the pump does not work, the problem should not be ignored.

06. Loss of Power

Various situations can cause the fuel lift pumps of your vehicle to fail. Even when under stress, a fuel lift pump is likely to keep working well.

It is also possible for an old one to work under certain conditions. The heavy load carried by vans and trucks can stress the vehicle and its parts.

Consequently, these parts could fail in a very short period.

All of these factors cause the vehicle to lose power. It can be dangerous for a vehicle to lose energy willingly.

This is because one of the symptoms of a defective lift pump is sudden surging.

A lift pump might encounter inconsistent resistance within its motor because of wear and tear resulting from prolonged use.

Common FAQs for the Cummins Lift Pump Failure Symptoms

How to know when my lift pump is bad?

You will notice a sudden change in your engine function after you’ve changed your fuel filter or if an opening in the fuel line was made.

Sometimes your engine can stop operating halfway. Al these are symptoms of a faulty pump.

What is the cause of fuel injector pump failure?

Your fuel injector pump can stop working because of dirty fuel in the tank. Over time, the residues in the fuel injector pump can settle inside and clog it up.

Clogging is most likely to occur at the spray tip since that is the area that clogs most frequently.

What does Cummins Lift Pump do?

In a nutshell, a lift pump supplies fuel to the injector pump. It does this by transferring fuel from low-pressure angles to higher-pressure pumps.

Is a fuel pump similar to a lift pump?

The modern speed limits of automobiles are due to the modern fuel pumps. Furthermore, fuel management can be improved by integrating them with fuel injection systems.

Lift pumps, however, assist in boosting the amount of fuel in the engine. Suction and airflow control is necessary to accomplish this.

Can a lift pump function always?

A lift pump’s run-time is controlled by the ECM. Moreover, it can run for a predetermined period before switching off.

The ECM controls the pump for 15-30 seconds whenever you try to start the car and it refuses.

Can a lift pump add power?

One of the reasons why some manufacturers boast about their lift pumps is their superior water separation. Having a lift pump with increased pressure nevertheless adds power.


However, the most common Cummins lift pump failure symptoms described in this article also refer to other engines. You can use this review regardless of the vehicle you drive.

Don’t ignore any signs that your lift pump has failed. Ignoring it can lead to further damage. Make sure you maintain your car frequently.

Your car needs to be checked every day, every three to six months, or once a year.

Leave a Comment