Diesel Truck Shuts Off While Driving – Why And What To Do?

It's dangerous if your diesel truck turns off suddenly, especially when you're driving on a highway. Now you're wondering why this issue occurs. Also, what can you do to fix the problem? We researched and consulted with experts and here's what we found.

A diesel truck's engine may shut off abruptly because of different reasons. The potential suspects often range from air entering the fuel supply lines to dirty air filters. Make sure to identify the cause of the problem. Then, use the correct steps to solve the issue at its source.

Keep reading as we discuss in greater detail the reasons your diesel truck shuts down while you’re still driving the vehicle. We’ll also tackle some possible solutions you may use that might help in solving this problem.

Big black dual rear tire diesel truck, Diesel Truck Shuts Off While Driving - Why And What To Do?

What Causes A Truck’s Diesel Engine To Cut Off While Driving?

A diesel truck’s engine might turn off suddenly, and it can be because of an underlying problem. Some of the possible culprits of that issue are:

Air In Fuel Supply Line

A truck’s fuel supply line could vacuum outside air. The appearance of air bubbles might result in your truck’s engine stopping suddenly. Aside from an engine stall, the air in the fuel supply line may also cause engine hiccups or a failure to start.

Cracked Diesel Fuel Injector

Cracked Diesel Fuel Injector - Car mechanic fixing modern diesel engine, closeup of hand removing injectors from cylinder head

Fuel injectors, particularly for diesel truck engines, are components that should provide precise fuel consumption for vehicles. Cracks and other types of harm encountered by a diesel fuel injector may cause an overflow or back leakage, resulting in an immediate stop.

It’s possible to diagnose if your truck’s diesel fuel injector is the suspect for the abrupt engine shutoff if you experience instances like:

  • Engine power loss
  • Reduced fuel economy
  • Rough idling
  • Engine misfires
  • Unknown sounds coming from under the hood (e.g., banging or knocking)

Discharged Battery

Discharged Battery - The booster cables and discharged battery, cold winter day

The typical diesel truck battery should last about five years. But a truck's battery lifespan might be lower than usual if exposed to extreme weather conditions frequently. Failure to notice the signs of a failing battery can make the diesel truck stop while you’re still driving in the middle of the road.

Some of the potential signs to watch out for that tell you to replace your truck’s battery are:

  • Engine backfires
  • Dim lights
  • Engine “clicks” when you turn the key
  • Sluggish performance
  • The need to press on the gas pedal to make the vehicle start

Dirty Fuel Filter

Dirty Fuel Filter - A mechanic takes out an old, dirty fuel filter after refueling with low-quality fuel.

An engine’s fuel filter is responsible for keeping dirt, rust, sediments, and other debris from entering the fuel line. But the filter’s performance can wear out over time with the accumulation of these particulates.

If the fuel filter becomes too dirty, it won't be able to provide sufficient air pressure to the fuel tank. This event may lead the diesel truck to stop quickly, even while you're driving the vehicle.

How Do You Fix A Truck’s Diesel Engine That Turned Off While Driving?

How Do You Fix A Truck’s Diesel Engine That Turned Off While Driving Car mechanic replace the new fuel filter at modern diesel engine

If you’re driving and your truck’s diesel engine turns off suddenly, the first step is to push the vehicle to a safe location. Don’t attempt to force the vehicle to start after a few tries. Otherwise, you might place irreparable harm to the engine and the truck’s other systems.

At this point, you have two options before you can proceed with the repairs:

  1. Release the parking brake and push the truck to a safe location, or
  2. Set your early warning device at a visible spot and wait for a towing service to pick up your vehicle

The first option can be a good choice if you have the strength to push your diesel truck. Choose the second option if you don’t have the muscle power to shove your vehicle to a safe spot.

Next, troubleshoot the truck’s engine to find the cause of the issue. That way, you can use the appropriate techniques to have the diesel engine up and running again.

Some of the possible solutions that you may use based on your troubleshooting results are:

Bleed Diesel Fuel Supply

Bleeding the air out of a truck’s diesel engine is a relatively DIY-friendly job. But you need to pay attention to the items required for this job to work.

So, continue reading this section to know the items you'll need and the steps to follow:

What You’ll Need

  • Diesel fuel
  • New battery
  • Wrench

Step-by-Step Guide

  1. Open the fuel line and pour diesel gas into the reservoir. Ensure that the poured fuel is slightly higher than the filter.
  2. Loosen the bolt on the fuel filter to allow the fuel to drain upwards.
  3. Close the bolt on the fuel filter after a few minutes.
  4. Ensure that your diesel truck’s engine has a full charge.
  5. Crank the engine, allowing it to build air pressure.
  6. Loosen the nuts on the fuel injectors to bleed the air from the fuel line.
  7. Tighten the nuts once you bled the air from the engine.
  8. Crank the engine again to test if it’ll start. Allow it to run for a few minutes to ensure that it won’t stop suddenly.

Check out this diesel truck battery on Amazon.

You can also watch the video below if you need a visual guide for the steps mentioned above:

Replace The Fuel Filter

Replacing your diesel engine’s fuel filter may provide results that last longer than cleaning that component. So follow these steps if you need help with this replacement job:

What You’ll Need

  • Compatible fuel filter
  • Allen key or hex wrench
  • Ratchet and socket wrench

Step-by-Step Guide

  1. Ensure that the ignition key is in the off position.
  2. Place the drain pan underneath the fuel reservoir.
  3. Use an Allen key or hex wrench to remove the fuel filter housing.
  4. Allow the fuel to escape to the drain pan.
  5. Loosen the filter cap with a ratchet and socket wrench.
  6. Remove the old filter from its housing and replace it with the new model.
  7. Secure the filter housing and refuel your diesel engine.
  8. Turn the ignition key to check if the engine starts smoothly.

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Watch the following video for a visual representation of this procedure:

What Is The Average Lifespan Of A Diesel Engine?

What Is The Average Lifespan Of A Diesel Engine - Mechanic working on a diesel filter, close up

A properly maintained diesel engine may last anywhere from 1,000,000 to 1,500,000 miles. That period also often translates to about 30 years of frequent use. In comparison, the typical gasoline engine only lasts about 200,000 miles before it needs replacing or significant repairs.

What Is The Best Diesel Engine In A Truck?

Take note that diesel engines often provide different benefits to their users. In other words, one diesel engine model can't supply all advantages to every truck user. Still, some engines for diesel trucks deliver more value than others. Some ideal candidates are:

1. 2022 Chrysler Eco-Diesel 3.0L V6

This diesel engine offers better fuel economy than many of its competitors. Reports indicate that it can provide 29 MPG highway. But it’s still possible to increase its fuel efficiency with proper care and defensive driving.

2. 2019 Cummins High Output 6.7L V8

This high-powered diesel engine can eke out about 1,000 lb-ft of torque. It also offers superb durability with its steel connecting rods, graphite iron block, and large bolts.

Final Words

Prioritize your safety before attempting to troubleshoot and repair your truck that suddenly shut down while driving. Once you’re safe, identify the reason for the failure. Then, use the solution that coincides with your troubleshooting efforts. Doing so should reduce the risks of further harm to the diesel engine.

If you want to know the answers to other truck-related concerns, check out these great reads:

Chevy Silverado Humming Noise – What Could Be Wrong?

GMC Sierra Adaptive Cruise Control Temporarily Unavailable – What To Do?