Why Does Your Ford F-150 Sound Like a Diesel?

If you’ve ever owned a Ford F-150, you probably know that it’s one of the most common trucks on the road today. This means that when something seems a bit wrong with your vehicle, there’s a good chance that a lot of other people are experiencing similar problems. One of the more common issues is a diesel-like noise that comes from under your hood.

A cold engine, the quality of fuel intake, a rattling injector, and cam phaser-related issues can cause rough idling and rattling that make your Ford F-150 sound like it has a diesel engine. Solutions would include removing and replacing the cam phaser in the worst-case scenario.

In a world where we’re all familiar with the sound of the diesel engine, it can sometimes be shocking to hear an unmistakable rumble from under the hood of your Ford F-150. Why would this happen, and what is causing that noise? In this post, we’ll cover four common causes & solutions for your truck sounding like a diesel.

rough idling can be caused by s few different things

1. Cold Weather

Behind the mighty rumble of your Ford F-150’s exhaust is a carefully calibrated system of heat, pressure, and chemical reactions that produce the engine’s most efficient burn. 

When you drive your truck in cold temperatures, it’s not just the air surrounding your vehicle that gets chilly – your engine and exhaust system will also be put through a cold cycle, which can cause changes in how your truck sounds.

While driving a cold engine, you may notice that it runs differently than when it’s been warmed up. In fact, how a car runs when it’s turned on cold versus when it’s fully warmed up is one of the first things technicians look at when diagnosing an issue with a vehicle.

Cold engines typically run poorly because they must be adequately lubricated before running and sounding like they’re supposed to. The oil in your engine keeps all its parts moving smoothly as they heat up and expand, but a cold engine doesn’t have enough oil yet to do its job.

How To Fix

Cold weather starts can be challenging for the typical American truck owner. The F-150 engine needs a certain amount of heat for it to be able to start. 

While you cannot avoid the knocking sounds when starting up, you should know that this is an ordinary feature of a cold engine. However, these sounds should not be excessive and are expected to cease over time

The best method to use when cold starting your truck is to simply let it sit and idle. Your engine takes less time than you think to reach its proper operating temperature, and when it does, it will warm up quickly. 

You should avoid revving your engine high during this process – too many revs can damage your engine. 

2. Using Low Octane Fuel 

Your F-150 engine is a finely tuned machine that needs to operate at peak performance to drive smoothly. 

If you’re using low-quality fuel, it could be causing your engine to run rough and essentially sound like a diesel engine. That’s why it’s essential to know the fuel grade recommended by Ford.

For example, if you notice rattling noises or rougher idling that makes the engine sound like a diesel when running, it could be due to using lower fuel grades than recommended for your model truck. 

How To Fix

The need to use high-quality octane fuel is becoming more and more prominent in newer vehicles. 

Since trucks like the F-150 are becoming increasingly more advanced and sophisticated, they require higher standards for fuel quality than in years past. The newer models are equipped with electronic spark timing controls and other technologies requiring higher grades for peak performance. 

Generally, trucks like the Ford F-150 should use high-octane fuel rated 93 or higher. The only anomaly is if you own an older model F-150 built in 1992 or earlier when 87 octane fuel was recommended across the board.

However, if you are unsure of what grade of fuel to use in your vehicle, check with your dealer or owner’s manual.

3. Injector Rattle

Most owners of the Ford F-150 models from 2008 and prior have reported issues with their injectors rattling. In most cases, it sounds like someone is firing off a machine gun, causing the engine to sound like a diesel. 

While it could be just one injector rattling away or several altogether, injector rattle happens because your truck’s fuel injectors have become dirty and clogged with various contaminants.

When these contaminants build up in the fuel injectors, they can prevent them from closing optimally, and when they close, they will often bounce back open again, causing an audible rattle noise. 

This problem can cause further issues, including poor fuel efficiency or misfires.

How To Fix

If you’ve ever driven an older vehicle, you’ve probably heard the sound of an injector rattle. It’s a distinctive knock or clatter that can come from any of the cylinders on your Ford F-150 when it is cold. 

The sound usually occurs when your truck’s engine is cold and goes away once the vehicle warms up. While it sounds like something you should have checked out, it’s not a primary concern. 

Ultimately, an injector rattle isn’t anything to worry about as long as your vehicle runs smoothly. You won’t have any problems driving while it’s happening, and your truck will run fine. 

However, if the rattle seems to be getting worse over time or if it’s accompanied by other signs of engine trouble, you might want to consider having your vehicle looked at by a professional service technician as soon as possible.

4. Cam Phaser Issues

A cam phaser is an engine timing device used in your F-150. It is a small, round device mounted on the engine, usually in a cylinder head. The cam phaser controls the amount of time that the valves are opened and closed during the combustion process.

Think of it as a timing mechanism. The cam phaser synchronizes the opening and closing of the valves. It does this by using hydraulic pressure to push on small arms that move or rotate other cams and gears to operate correctly with each other.

This device’s purpose is to ensure that all of the engine’s valves open and close at the proper times, thus ensuring that an air-fuel mixture enters at just the right moment for combustion rather than being too early or too late.

At first glance, the only way you’ll know something is wrong is by paying attention to the symptoms you’re experiencing.

If your F-150s cam phaser fails to do its job correctly, you could experience severe issues with your engine performance, including rough idling, rattling, and insufficient oil pressure, resulting in your engine sounding like a diesel engine.

Additionally, if you notice that your engine isn’t firing up correctly or that you have trouble turning over when you try to start your truck in the morning, this could indicate that something is wrong with your camshaft phaser.

How To Fix

Most people don’t even think about the phasing mechanism on their F-150s camshaft until something goes wrong. The recommended way to address issues with your cam phaser would be to remove and replace the entire mechanism before it causes further damage to your engine. 

While this is a daunting task, many individuals have the mechanical skills to tackle removing and replacing a cam phaser. Plus, this would save you money on labor costs.

For the mechanics out there, here is an in-depth YouTube video to assist you along the way:

Ultimately, it’s best to get your cam phaser replaced as soon as possible by a professional mechanic

Your Ford F-150 double honks when you lock it? Several problems cause the issue. Click on the link to learn more about the reasons and methods to fix them.

Luckily there are easy ways to fix most issues.


The Ford F-150 is one of the most popular vehicles on the road, and it’s easy to see why. The vehicle has been around for many years and has undergone several changes. 

If you own an older version of this iconic vehicle, you’ll likely deal with more diesel-sounding noises. These issues can be related to less serious causes, such as cold weather, low-octane fuel use, and injector rattling. 

If you’re experiencing cam phaser issues, you should remove and replace it immediately because it can lead to more significant mechanical problems.