Why Are My Cat C15 Injectors Failing? The 9 Most Common Problems

The Caterpillar C15 diesel engine is synonymous with heavy machinery. What makes them so popular is their reliability, durability, and simplicity. However, nothing lasts forever, and fuel injector issues are inevitable.

Cat C15 Diesel Fuel Injector

Do you think the fuel injectors on your Cat C15 diesel engine are failing or are about to fail? We’ve dedicated this entire post to the potential problems that a defective Caterpillar C15 fuel injector might have. 

How do fuel injectors fail? What to do when they fail? All these plus many other questions related to Cat 15 diesel Fuel injectors will be answered. If you think your injectors have failed or are going to fail, get in touch with our knowledgeable staff at DFI. We’ll get you back up and running in no time! 

If you want to learn more about fuel injectors and how they work, Highway & Heavy Parts has a great article that explains diesel fuel injectors.

The 9 Most Common Failing C15 Fuel Injector Problems

The fuel system in any diesel engine, including the Caterpillar C15 engine, is complicated. We’ve put together a list of the most common Cat C15 fuel injector failure symptoms and what may cause them. Remember, always get a certified shop to tell you exactly what the problem is before going in and blindly replacing parts.

1. Poor performance 

Does your Cat C15 engine not have the same “get up and go” as it once had? It is more sluggish and usual? Faulty fuel injectors may be the ones to blame.

2. Misfire

Engineers have designed the Cat C15 diesel engine to work in a variety of applications from farming, to construction equipment, cranes, and even drill rigs. One thing it is not designed to do is a misfire. 

A misfire is when one or more cylinders have incomplete combustion, resulting in rough idle. Anyone who’s spent a considerable around of time with the C15 will immediately know if it is not running right. 

3. Fuel Knock 

When compared side by side, diesel and gasoline-powered engines are quite different in design. Gas-powered engines need a source of ignition to help combust the fuel. This is often done by a spark plug. 

Diesel engines on the other hand, compress the fuel to a point where it combusts on its own. Unfortunately, a failing diesel fuel injector will not provide the proper amount of fuel, which ends up causing a fuel knock. Although similar to a misfire, it is not the same.

4. Check Engine Light

Most vehicles, regardless if they are used for commercial or civilian purposes, will be equipped with some sort of check engine light. Regardless if you think it’s nothing major, check engine codes should be read as soon as possible to avoid doing any further damage.

5. Hard Start

Diesel engines are notorious for hard starts, especially in the colder months. No matter how many miles or hours your Caterpillar C15 diesel engine has on it, any change in the amount of time it takes to fire it up should be noted and resolved as soon as possible. 

If it takes longer than usual and is accompanied by one or a combination of the symptoms noted in this article, fuel injectors should be on the list of possible suspects.  

6. Poor Idle

A poor or uneven idle could be caused by plugged, damaged, or faulty fuel injectors. Of course, a rough idle could be the result of other problems, but the fueling system should be first on the list of possible factors.

7. Smoke

Rolling coal has always been popular amongst the diesel crowd. These days, due to increased emissions, black smoke should be a cause for concern. If you notice a large cloud of black smoke coming from the exhaust of your Cat C15 engine, your fuel injectors could be to blame.

8. Unusual Odor

We all love the smell of fresh diesel in the morning, right? But there is a difference between a healthy Cat C15 engine and a sick and/or tired one. If you are around the C15 day in and day out, an extra rich diesel odor could be a sign of damaged fuel injectors. 

9. Decreased Fuel Efficiency 

Finally, a significant drop in fuel efficiency, even if your driving style remained consistent, is a sign that the fuel injectors may need replacing or repairing. DFI has Caterpillar C15 remanufactured injectors ready in stock and ready to ship out to you.

How Do Diesel Fuel Injectors Fail?

Fuel injectors are extremely sensitive to change, and Cat C15 injectors are no different. There are two main ways that an injector can fail. Those are mechanically and electronically. This section is dedicated to examining each type of failure in closer detail. 

Mechanical Failure

C15 fuel injectors are not immune to physical wear and tear. Over time, debris, water, and even air can get into the fuel system. This means the physical condition of fuel injectors can greatly deteriorate. Age plays a big role in the physical deterioration of fuel injectors. Seals, springs, and everything in between can affect the mechanical condition of fuel injectors. 

Electronic Failure

Whether you like it or not, electronics are part of everyday life and this includes fuel injectors. Caterpillar C15 fuel injectors are equipped with selenoids that tell the injector exactly when to open and close. Unfortunately, time takes a toll on the selenoids and can cause the selenoids to stop working. 

Noted above are just the two main types of fuel injector failure. For more, in-depth information, Highway and Heavy Parts has an article covering faulty fuel injectors and their replacement.

What Should Be Done About Failing Injectors?

Injectors are no doubt an integral part of your fuel system, and when they fail, your engine goes down with it. The first thought that comes to mind when an injector fails, is to rebuild it. This is something that is best left to the pros, like the ones at DFI.

Buying a remanufactured fuel injector is a great alternative to purchasing new. They are oftentimes made alongside the original ones by using only certain components from donor injectors. The best part is that they cost a fraction of brand new injectors. A dollar saved is a dollar earned. 

We pride ourselves in selling only the highest quality Cat C15 fuel injectors that meet or exceed factory OEM specifications. Keep your mind at ease by going with DFI today.

Need those fuel injectors? Our ASE Certified Technicians are ready to get you the parts you need! Give us a call at 1-855-212-3022!

How To Choose The Right Diesel Common Rail Injectors: OEM Vs Aftermarket, New Vs Reman

Common rail fuel injectors are relatively new to the diesel combustion engine party. They are intended to bring forward several advantages such as improved fuel economy, lower emissions, and better torque.

Diesel Engine Common Rail Fuel Injector

Although new, they have proven to be an invaluable asset for both drivers and companies alike. On top of being more efficient, common rail fuel injectors help keep the noise down on the already noisy diesel engine. 

No matter what the reason is, when the time comes to replace those old injectors, DFI has got you covered. We proudly carry the highest quality Bosch fuel injectors. Because getting the most from your truck is what matters to us the most!

How do you know you are getting the best bang for your buck? What injector options do you have? These questions, amongst many others, related to choosing the right common rail fuel injectors will be answered in the article below.

OEM vs. Non-OEM Fuel Injectors

One of the most common asked questions we get is: “Are injectors built to OEM standards different from regular injectors?”

The short answer is yes. Common rail fuel injectors are not all made the same, just like not all diesel engines are the same. Luckily, companies like Bosch manufacture all their injectors to a very high standard. 

Several hours of research and development(not to mention dollars) have gone into testing every model they produce. The result is an injector that is vastly superior to what the competition offers. What does this mean for you? This means that you will be able to get many more trouble-free miles by going with a brand-name injector. 

We performed several tests designed to expose any signs of wear and weakness in any diesel fuel injector. After adding everything up, we concluded that brand name companies such as Bosch reigned supreme over those “other” brands. 

What may seem like a good deal now, may end up causing your more trouble down the road. Here are some of the most commonly encountered issues when going with cheap, low-quality common rail fuel injectors:

  • Poor fuel economy 
  • Decreased power 
  • Added noise 
  • Starting problems 
  • Premature failure 
  • Excessive smoke 
  • Potential engine damage 
  • Increased risk of exhaust damage 

The problems mentioned above are the most common. A low-quality or poorly rebuild diesel fuel injector is bound to have one or a combination of the symptoms noted above. Although problems may not show up initially, it’s not a risk you should have to take. 

Something as simple as a damaged fuel injector can mean an entire engine rebuild. In extreme cases, the damage can be so bad, that the only option left is a full engine replacement. 

We’ve put together a series of images that will show the difference in quality between OEM quality such as Bosch, and the “others guys”.

armature_1 | Highway & Heavy Parts
armature_2 common rail fuel injector | Highway & Heavy Parts

Image 1 shows what a Bosch Injector is supposed to look like when brand new. Image 2 on the other hand, is what you get when you go with a remanufactured injector that is not held to the same standards.

sealing_surface_1common rail fuel injector | Highway & Heavy Parts

Valve body sealing surfaces are also greatly affected when. The first photo is of an OEM-spec quality injector and the second photo is one of its competition. It’s clear which one is the better choice in this lineup. 

Trying to regrind the surface may seem like a good idea for certain applications. However, when talking about common rail fuel injector valve bodies, it’s better to be left alone.

sealing_surface_2 common rail fuel injector | Highway & Heavy Parts

Lastly, we have a photo of the entire valve body. The difference couldn’t be any clearer. A non-OEM-approved injector will likely use the valve body from a donor unit. This is simply not acceptable by DFI. 

The pitted, rusted, and discolored body in the second photo can lead to increased friction during operation, all of which will lead to negatively impacting performance.  

Common Rail Fuel Injector Options 

When choosing a new fuel injector, there are three main options available. Let’s have a look at what they are: 

New Injectors

If your old injectors core can’t be reused or just want brand-new injectors, Bosch is the number one brand. Customers, regardless if they are engine manufacturers or owner-operators, choose Bosh due to their reputation for reliability and superior build quality. 

Each injector with the Bosch name is painstakingly manufactured to strict OEM standards so that you can benefit from thousands of trouble-free miles. 

Remanufactured Injectors 

Remanufactured injectors are as close as you can get to new without the price tag. Buying from a reputable dealer is one of the most important factors when going the reman route. This ensures that most components affected by wear are replaced. 

DFI for example gets their common rail built in the same factory as new Bosch fuel injectors. This ensures that each remanufactured injector we sell is just like new! What does this mean for you? Strict emissions requirements are met and in some cases exceeded, giving you an injector can, in some cases, is better than new. 

Rebuilt Injectors

When talking diesel fuel injectors, rebuilt and remanufactured are two completely different things. A rebuilt common rail fuel injector when purchased from a reputable source(such as DFI) will still meet original OEM specifications. While it’s true that they won’t have as many components rebuilt as a remanufactured one, the finished product will still second to none. 

No matter which choice you settle on, DFI is sure to have something for your specific needs. All of our new, rebuilt, and remanufactured Bosch fuel injectors are perfect for your truck!

Our ASE-certified techs are ready and willing to answer any questions you may have about common rail fuel injectors or most other truck parts. Give us a call at 855-212-3022 or visit our contact page!

Diesel Common Rail Fuel Injector Problems, Symptoms, and Causes Explained

Fuel injectors, although small in size, play an extremely important role in the way your engine performs. Common rail fuel injectors are the most widely used type of injectors in diesel engine trucks. If you’ve noticed a drop in performance, heavy smoke, misfires, etc., it could be that your common rail fuel injectors are the ones to blame.

Diesel Engine Common Rail Fuel Injectors

This post is dedicated to answering some of the most common questions asked when about common rail fuel injector failure and what causes them to fail. DFI is committed to giving you as much information as possible so that when a problem appears, you know what to do!

6 Common Rail Fuel Injector Failure Signs

There are several signs that a common rail fuel injector is or will become defective. The symptoms mentioned below can occur by themselves or are combined with other issues, making the initial problem that much harder to pinpoint.

1. Smoke

Added smoke is one of the most common issues of a failing fuel injector. While it is normal for a diesel, or any internal combustion engine for that matter to produce smoke, increased smoke is something to keep an eye on.

2. Light Misting 

Fuel injectors are engineered to create a fine mist or atomization when open, making the combustion process that much more efficient. When a fuel injector is clogged, the fuel coming out is something more of a slow drip.

3. No Start 

Common rail fuel injectors could be the reason that your diesel engine doesn’t want or has an extremely hard time starting up. 

4. Black Smoke

Rolling coal is popular on normal trucks, but an unnecessary amount of black smoke coming from your rig is never a good sign. This applies to stock ECUs that don’t have an aftermarket tune installed. 

5. Clogged DPF Filters 

Failing common rail fuel injectors can end up putting too much fuel in the combustion chamber. Unburned fuel will come out in the exhaust stroke and can end up clogging the DPF filters.

6. Short Regeneration Times

If the regeneration period seems to take less time than usual, you might want to have a closer look at your injectors as they may be to blame for this issue. 

Causes of Common Rail Fuel Injector Problems 

Most of the problems noted above are due to the injectors remaining stuck in the open position. Why does this happen? It could be due to several reasons, but most likely is caused by water or dirt that has gotten into the system. Changing your fuel filter regularly is critical if you want to reduce the chance of this happening. 

A leak test is can be performed to make sure common rail fuel injectors operate within their specified parameters. Unfortunately, some Duramax engines came with stock injectors that were poor in design from the very beginning. Therefore, a leak test is more common on these types of injectors. 

Mileage plays a big role in the overall condition of common rail fuel injectors or any engine component for that matter. Its common knowledge that higher mileage engines will be more prone to a higher risk of issues and injectors are not immune from that. 

Ball seat erosion is common on engines that have seen have seen countless hours and miles of hard use. This happens when the pressure of the fuel is so great that it ends up physically deteriorating the fuel injector’s tips. Luckily, these issues can be resolved by rebuilding the injectors.

Lastly, time is one of those things that just can’t be turned back. Even if you’ve babied your truck and made sure didn’t put on too many miles, time itself can take a toll on injectors. As far as we know(or anyone for that matter), there isn’t much one can do to turn back the hands of time. 

What Can Be Done To Resolve Common Rail Fuel Injector Problems?

The best thing one can an owner can you to prevent common rail fuel injector problems is to get the right get quality fuel. Not all diesel is created equally, and trying to save a few dollars by going to a cheaper gas station to fill up may end up causing you more in the future. 

Operating conditions are another factor that can end up wreaking havoc on common rail fuel injectors. Yes, diesel engines are made to be more robust when compared to gasoline engines, but they can’t go on forever without proper maintenance. 

Finally, condensation is one of those issues that is not taken too seriously until it’s too late. As the diesel in your tank warms up, the empty space in your fuel tank creates moisture which can make its way to the injectors and create problems. Draining your filter regularly can help with this. 

If you notice any of the problems mentioned above, one of the first steps is to scan your engine for fault codes. An authorized shop with the proper equipment should be able to tell you if the flow rates are equal or if one injector is reading more/less than the rest. Even if there isn’t a check engine light on your dash, your injectors could still be faulty. 

DFI is dedicated to helping you resolve any diesel engine problems, regardless if they were listed in this post or not. Our ASE-certified techs are standing by and ready to help you resolve any issues you might have. Give us a call at (855) 212-3063 or request a quote online today!

What Are Diesel Fuel Injector Trim Codes? How To Install, Locate, and More

Today’s diesel engines are complicated. Gone are the days when you could fix your truck on the side of the road with a couple of common hand tools. 

Trim codes, or trim files as some may call them, is information that tells your ECM (engine control module) how long the fuel injectors need to stay open.

Diesel Fuel Injector with Trim Code Disc

Without proper trim codes, you could run the chance of rough idle, poor fuel economy, and in some cases, even engine damage. However, the latter is quite rare and seldom happens. 

Keep in mind that some engines do not require trim codes to run. But, as with any unknown, always make sure you check the instruction manual.

This article is intended to make sense of what trim codes are, why you need them, and what can happen to your engine if you don’t have them. 

What’s the Function of Injector Trim Codes?

Generally speaking, an injector with the same code should have the same flow rate, right? In theory, this is correct, but not all injectors are 100% identical. 

We know that each truck will have parts that wear at different rates depending on how it is used. And this applies to injectors as well. 

Factors such as magnetic forces, friction, machine tolerances, and so on, all play an important role in fuel injector output rates. 

A trim code can adjust the flow of each injector, allowing for a net output that is virtually the same, regardless of wear or mileage. These small differences eventually add up, and not having the right trim code can end up costing you in the long run. 

Proper Trim Code Installation 

Having the right trim codes is vital to your engine’s performance and installing them can be a simple process if you know what you are doing. 

Most injectors should have a serial number stamped on their exterior. This will give you or the mechanic working on your truck all the information required about them. 

If you are lucky, the injectors will come with a physical disc containing all the trim information, making things that much easier. The disc’s information would then be uploaded on a computer which in turn would be connected to the truck’s ECM. 

Depending on the make and model you own, some of the serial numbers may need to be input manually into a program that then tells the truck’s brain (ECM) the required data for each injector. 

How Do I Locate The Trim Code?

As previously mentioned, a trim code is almost certainly a must for injectors that require them from the factory. But how do you find them? In most cases, injectors come with a trim code disc so that they can be programmed in the ECM. 

Delphi fuel injectors are the perfect example. Caterpillar C7 and C13 engines come with their own unique trim codes, and DFI supplies each injector with the necessary information via a disc. Normally, a trim code should be physically stamped on each injector so that it can be easy to read for the installer.  

Are Trim Codes A Must?

Simply put, trim codes should be installed if your injectors came with them from the factory. However, it’s not something that will generally impact performance.

If your injectors come with a trim code from the factory, running the engine without that information will only end up causing problems. It is a necessary evil that needs to be taken into consideration on today’s modern diesel engines. 

The saying “if it ain’t broke, don’t fix it” should certainly be used as a motto in these situations. Unless your engine starts acting funny, there is no need to mess with injector trim codes. 

Nevertheless, if you are putting in new injectors and you don’t tell the ECM that, you could run into a series of issues. They include, but are not limited to rough idle, power loss, over-fueling or under-fueling, and increased emissions. 

To keep you from losing sleep, we are here to tell you that in most cases, trim codes will not noticeably affect your truck’s performance. In fact, we’re willing to bet that most owner-operators don’t even know that injector trim codes existed. 

If you have installed new injectors and haven’t noticed a negative effect, leave everything well enough alone. 

Final words

Fuel injector trim codes are a mystery to most owners and even some experienced shop owners. It is a subject that can cause a lot of doubt and confusion. 

This article should help you better understand what injector codes are and how they can be used on your diesel engine. 

If you have any other questions related to fuel injector trim codes or engines in general, our experienced, ASE-certified staff is here to help. Give us a call at 1-855-212-3022.

Diesel Fuel Injectors Explained: Injectors Failing? Should You Replace Them? Q&A

Fuel injectors. For some, they are a subject shrouded in mystery. For others, they are a complex piece of engineering that has made engines much more reliable and efficient. No matter how you view them, we are here to help shed some light on this subject.


Why are my fuel injectors failing? What kind of fuel injectors are there? Should I replace my injectors? We are going to answer these questions and many more for you in this article. The more you know, the easier it becomes to diagnose the problem.

No matter if you own a repair shop or just a truck, knowing how fuel injectors work is imperative. However, if the unfortunate happens DFI is here to help!

Why Are My Diesel Fuel Injectors Failing?

One of the most common questions we get about fuel injectors is why they fail. While there is no one definitive answer as to why injectors fail, here are some of the most common reasons.

Modern injectors are complicated, no matter how small or simple they look. Simply put, a fuel injector may fail due to either a mechanical or electronic malfunction.

Most injectors are controlled electronically, meaning that they can fail even if the mechanical part is still operational. The only ones that are exempt from this problem are ISX injectors, which do not have a solenoid telling them when to open or close.

On the mechanical side, however, dirt, grime, dust, or any other debris can still wreak havoc on any type of injector. In most cases, They fail due to contaminants making their way into the fuel. That is why keeping your fuel system clean is extremely important.

Alternatively, you could have done everything in your power to keep the injectors clean and they still failed. Wear and tear will eventually take a toll on your injectors, and they will fail. You can’t expect them to last forever, right?

Should I Add New Fuel Injectors During An Engine Overhaul?

Of course! Anytime you are doing major work to your engine and you have easier access to your injectors, they should be replaced. Generally speaking, fuel injectors have very tight tolerances, and over time (800,000 to 1,000,000 miles) those tolerances are no longer what they used to be.

“If it ain’t broke don’t fix it”. That statement may be true in certain scenarios, but if you notice your fuel consumption increasing and the power decreasing, it may be a sign of defective or worn-out fuel injectors.

Injector heads are dotted with smaller holes intended to create a fine “mist” when fuel pushes through them. Over time, these tiny holes become enlarged, and all of a sudden you have a shower head instead of perfect atomization. Yes, this may be a very simple explanation, but it is what ends up happening when fuel injectors reach their best before date.

One may think that replacing the fuel injectors will help restore lost power, improve acceleration, and reduce hesitations. That person would be 100% correct. In fact, many fueling issues can be resolved by simply replacing your fuel injectors.

How Does A HEUI Injector Differ From A Regular Injector?

A HEUI or hydraulic electric unit injector is better in almost every way when compared to a regular fuel injector. When injectors were first introduced on the market, they were entirely mechanical.

Nowadays, some injectors rely on an electrical signal to move the plunger in and out when a need for fuel is triggered. In simple terms, this means that the amount of fuel, its pressure, and timing can be closely controlled, allowing for an overall more efficient system.

Alternatively, ISX diesel fuel injectors are mechanical and worked entirely on pressure supplied by the fuel pump. While this may seem like a simpler and more durable alternative, there is a reason why they aren’t used in all diesel engines.

What Is The Difference Between New And Remanufactured Injectors?

Brand new injectors are few and far apart. Why you may ask? It’s simple! New injectors are very expensive and most defective ones can be rebuilt. Much like rebuilding a car’s engine, most parts can be carried over when overhauling it.

All of our remanufactured injectors are thoroughly cleaned, inspected, and have any defective components replaced. It is like buying brand new injectors at a fraction of the original price.

Sometimes, getting a new part does not make sense financially, and if we can help you save a buck, you best believe we are going to do it!

What Makes A Good Injector Core Charge?

Having a good core is essential if you plan on exchanging your defective or worn-out injectors for top-quality, rebuilt ones. Although we try to make things as simple as possible, there are a few general conditions that must be met when sending us your old injectors.

Firstly, the models must be the same. You cannot send exchange “X” injectors for “Y” injectors. On top of that, injectors with broken terminals mean they cannot be salvaged. Therefore, we cannot accept them. Finally, broken or crushed tips will not help us in the rebuilding process and is another important factor that we take into consideration when we look for a good core. Besides that, we are understanding and will try to accommodate you and your situation.

Even if you are on the other side of the country, we will mail you the new ones, along with a prepaid label. This way, when you receive your new-to-you injectors, the old ones will be mailed back right away. It’s as simple as that!

We hope this article helped with your injector-specific questions. If you have any other further questions, or experienced staff would be happy to help. Call us at 844-215 3406 or request an online quote now!

When Is It Time To Replace Diesel Fuel Injectors? 6 Common Symptoms

The fuel injectors on your common rail diesel engine can be the cause of several issues including poor MPGs and sluggish performance. Injectors play a very important role in making sure you get optimal power while not using up unnecessary amounts of fuel. 

When to replace your diesel fuel injectors

But they aren’t made to last forever, and if if you notice any of the warning signs listed in this post, it may be time to change out those old injectors. 

6 Signs It’s Time To Replace Your Diesel Fuel Injectors

Knowing when to replace your fuel injectors is key. Not replacing them on time can lead to further problems down the road as well as higher operating costs now. 

Here are the most common signs: 

1. Decreased Fuel Economy

As previously mentioned, injectors play an important role in making sure your engine runs efficiently enough while not negatively affecting power. 

Poor MPGs are one of the most common signs encountered by bad or worn-out fuel injectors. There are several reasons this may happen. The most common being clogged fuel injector heads due to not changing the fuel filter regularly or bad quality diesel.

2. Blue Smoke

It doesn’t matter what vehicle you drive. If you notice blue smoke coming from the exhaust, alarm bells should be going off in your mind straight away. 

The most common cause of blue smoke is due to engine oil entering the combustion chamber. But it can also mean that the fuel injectors may have something to do with it. In either case, it is not an issue that will fix itself. 

3. Smell Of Raw Fuel

We love the smell of fresh diesel as much as the next guy, but this smell should be only encountered at the gas pump when filling up.

If you notice the smell of raw fuel frequently, it may be a good indication that your fuel injectors are leaking and will likely need to be replaced or rebuilt. Not doing so will only reduce fuel consumption and may pose a fire hazard. 

4. Fuel In the Oil

Engine oil is designed to act as a lubricant and reduce the wear of metal on metal contact. Diesel engines work even harder when compared to traditional gasoline engines, therefore having the right viscosity or thickness becomes critical. 

When introducing fuel in the oil, the lubrication properties of the engine oil get decreased and will also increase oil pressure at the same time. Worn out or damaged seals and O-rings on the injectors could be one of the culprits and should be replaced right away. 

5. Engine Misfire

Engine misfires, unlike the other symptoms listed on here, can be easier to spot. Simply put, if the combustion process doesn’t occur within certain parameters, the fuel will not ignite when required. 

Misfires are easy to diagnose but can be harder to find out what initially caused them. One of the most common reasons an engine misfires can be directly attributed to faulty fuel injectors.

6. Knocking

Much like misfires, engine knocking has similar symptoms. But, unlike a misfire, knocking occurs when the fuel in the cylinder combusts before or after it is supposed to. You may also hear people referring to knocking as detonation or pre-detonation.  

Worn-out fuel injectors may also be the course of this issue. If the injectors do not deliver the right amount of fuel at the exact moment needed, the result may be an engine knock. 

What To Do If You Think Your Common Rail Fuel Injectors Are Failing

There are several things you can do if you think your common rail fuel injectors are not working as they should. 

If any of the above symptoms are occurring, the first step is to have your vehicle scanned and see if any error codes related to faulty fuel injectors come up. It can be done with a common OBD2 scanner by anyone, but for more in-depth information we recommend taking it into a shop. 

Once the injector/s is determined to be the problem, the next step is to have them sent into a certified facility that will perform specific tests and determine what can be done, if anything, to repair them. 

Unfortunately, in some cases, original injectors cannot be salvaged and must be replaced. That is why they should be properly diagnosed before deciding to replace them in the first place.

Even if you do not think the injectors are faulty, but you hear an engine knock, it should be cause for concern. Having the problem professionally diagnosed can tell you with certainty if your fuel injectors need to be replaced. 

Putting the problem off will only make things worse and could potentially cause more damage in the long run. 

If you find that you need new injectors, Highway & Heavy Parts is here to help! We have a great selection of replacement injectors for your diesel engine.

Our on-staff ASE Certified Technicians can help make sure you’re getting the right injectors. Having your VIN on hand can help make sure you get the right parts. 

Our technicians are some of the best in the business and ready to answer any questions you may have. Give us a call today at 844-304-7688 or request a quote online now.

Why Did My Diesel Common Rail Injectors Fail? 4 Common Causes

You’ve just been told that you need to replace your diesel engine fuel injectors. 

But what exactly caused the failure that led to this point? 

Diesel Engine Common Rail Injector Failure

There are several things that could cause problems with your diesel engine common rail fuel injectors, including poor fuel filtration, fuel contamination, improper installation, and the use of non-OEM quality remanufactured parts.

We’re taking you through each of these problems so you can better understand what’s going on in your engine, and so that you can better prevent these problems in the future. 

4 Common Causes of Common Rail Injector Failure

1. Poor Fuel Filtration

One of the main problems you might be having with your common rail fuel injectors is poor fuel filtration. 

A common issue you’ll see with these systems is ball seat erosion. This can occur when the small ball that seals the passage of the magnetic valve at the heart of the common rail injector is not sealing properly. A correct seal is vital for proper function, so when abrasive contaminants erode and damage that ball seat, you won’t be getting proper injection. 

ball seat erosion graphic | DFI

If this happens in your diesel engine, you might notice:

  • Excessive Smoke
  • Starting or Idling Problems
  • Potential Engine Failure


uniform grinding on a new valve body graphic | DFI

To help ensure that your common rail fuel injection system functions properly, use filters that have the same micron rating as the OE filters. Be sure to follow the oil change interval recommended by the OE. 

2. Fuel Contamination

Did you know that a large number of diesel engine problems are caused by contaminated fuel? This is true of fuel injectors as well. Another major problem you can have with your common rail fuel injectors is corrosion caused by water contaminating the fuel. 

Common Rail Injector Corrosion Around Injector Inlet

This contamination can be the result of water entering a fuel storage tank. These tanks have a vented cap that allows air to enter, equalizing pressure as fuel is removed. This air is obviously from the outside, and contains moisture. So, as this air enters the tank, the moisture condenses into water inside the tank. 

Diesel fuel injector corrosion around injector inlet and return

Fuel contamination symptoms include:

  • Poor engine performance
  • Engine idling problems (vibration)

To help prevent this problem, make sure you’re purchasing fuel from a reputable provider. Using the correct fuel/water separator can also help prevent contaminated fuel from damaging your diesel engine. 

3. Improper Installation

combustion residue on the outside of a fuel injector

Installation problems can also cause a failure in your common rail injectors. This can range from missing sealing rings, to incorrect tightening torque, to incorrect cleaning of the nozzle. Improper installation techniques can cause:

  • Poor Performance
  • Engine Misfiring
  • Black Smoke
  • Check Engine Light (MIL)


Diesel engine solenoid stud graphic

Problems from incorrect installation can be avoided by always following your engine manufacturer’s maintenance instructions.

4. Non-OEM Quality Remanufactured Parts

As we’ve mentioned before, not all remanned parts are created equal. Some will give you more problems than they’re worth. The quality of the injector depends on the remanufacturing process and the components that are replaced in it.

Sometimes, an injector will be marketed as rebuilt, but really it was only refurbished.

You’ll probably get a good deal on these parts, but they won’t keep your engine running in peak condition. 

To avoid this problem, make sure you’re buying OEM quality remanufactured injectors. Here at DFI, we’re proud to carry Bosch common rail fuel injectors. These injectors are the same as OE in design, engineering, materials, manufacturing, and quality control. They meet all the latest emission requirements and include all the OE updates, so they might even be better than the ones you’re replacing. 

Why Buy From DFI?

  • At DFI, we don’t sell inferior fuel injectors from discount suppliers. We only sell you the best quality fuel injectors for your needs, at fair, affordable prices. Not only that, we’re a reputable, OE-Certified remanufacturing facility with over 40 years experience.
  • Our expert technicians solve virtually any diesel fuel system problem, offer you a fast and accurate estimate, and provide expert repair and installation advice, so you can make a confident purchasing decision.
  • We know that you need to get parts fast to service your customers. That’s why we at DFI make sure that we have readily available fuel system parts for your specific diesel engine and can typically ship your parts the same day.
  • Our injectors are remanufactured to the highest quality standards, with upgraded parts that meet or exceed OEM specifications. Parts are tested using the latest OE-approved diagnostic testing equipment and technology.
  • All wearable components are replaced with new OE parts and meet the latest emissions requirements.

Are you looking for the highest quality diesel engine replacement parts? Our ASE Certified Technicians can help you get the right parts for your engine! Call us at (855) 212-3022, or you can pick it up yourself.

Our service is located at 1800 South Wenona St., Bay City, MI 48706. It can be easily reached from Bay City, Midland, Saginaw, Flint, Michigan, Mid-Michigan, Central Michigan, and the Great Lakes Bay Region.

Why Does my Navistar MaxxForce 13 Diesel Engine Keep Misfiring?

Semi Truck With Navistar MaxxForce 13 Diesel Engine

Engine misfires are pretty common at diesel engines. Recognizing the cause of a misfire can be difficult. Sometimes misfires can be challenging to diagnose, even for skilled technicians. It would be best if you started diagnosing the misfire on your car as soon as possible, as postponing it can only increase your repair costs as time goes by.

Why Do Diesel Engines Misfire?

There are a few causes that appear more often than others. Even though a misfire may have its origins in one or more systems, the primary suspects are damaged or clogged injectors.

The first place to start looking for the misfire is by inspecting the fuel system. The fuel/air mixture needs to be balanced for the engine to start and work properly. This balance can be damaged if the fuel injectors get clogged, preventing the fuel from getting to the combustion chamber. The incapacity to ignite the air/fuel mixture in the combustion chambers will result in the engine not turning over.

After a while, your engine’s fuel injectors may weaken or get clogged up, especially if you mainly drive short distances. Stopping and starting the engine frequently can accelerate the process. Damaged or dirty fuel injectors can restrict fuel flow into the cylinder leading to an improper air/fuel ratio.

Other causes of failure for your rail injector include low fuel filtration, fuel contamination, improper install, and usage of non-OEM quality remanufactured parts.

6 Signs Your Diesel Fuel Injectors Are Faulty

  1. Rough idling – the engine seems like it will stall when you stop.
  2. Struggling to start – If the engine gets too much or too little fuel, you may experience issues when trying to ignite.
  3. Fuel odor – The smell of fuel inside the cabin while running might suggest a leak somewhere. This means that your injector is damaged, and it enables the diesel to flow out of the nozzle.
  4. Excessive exhaust smoke – Injector deposits and clogged fuel filters can result in incomplete and uneven fuel combustion, ending with a thick smoke emission from your exhaust.
  5. Fuel consumption went up – Faulty injectors will burn more fuel, which will lead to increased fuel combustion and will have a direct impact on your vehicle’s efficiency and performance.
  6. Check engine light on – The check engine light could be triggered to turn on if the engine gets too much or not enough fuel.

If you’re experiencing or suspect any of the above problems, you need to give us a call!

When fuel injectors fail, you are left with a diesel engine that performs below par. This is a financial burden to you and costing you time having to pick parts up. Who wouldn’t instead save that time and money?

Diesel Engine Part Options For Your Fuel Injectors

0-986-435-577 Remanufactured, Common Rail Fuel Injector for Navistar Maxxforce 13

Remanufactured, Common Rail Fuel Injector for Navistar Maxxforce 13

In stock, we now have genuine Bosch injectors for your Navistar Maxxforce 13. Call about our featured part: OEM# 0-986-435-577.

This remanufactured, authentic Bosch OEM replacement fuel injector for Navistar Maxxforce 13 diesel engines has been made with new and reconditioned OE parts. What’s more, all OE updates are included. You might be surprised to discover that this could exceed the one it is replacing.

As an esteemed diesel fuel injection remanufacturing facility, DFI Reman Center is comprised of OE-certified, factory-trained technicians. For more than 40 years, mid-Michigan has relied on us to supply OEM fuel injection parts to off-highway, agriculture, and construction industries. Furthermore, DFI is a single source for all OEM fuel injection production. On-highway OEM dealers and repair shops used to favor specializing in producers of single OEM.

However, trends now show that many prefer serving multiple OEMs. The combination of our quality resources and advanced knowledge puts DFI in a position to provide superior solutions to the OEM makes, optimizing core products. The DFI experts deliver high-quality OE replacement parts to local Michigan markets with inventory on the shelf, getting you back on the road as soon as possible.

Main Features of our Bosch injector:

  • Tested and calibrated using OE specifications.
  • The injector was built using tooling fixtures and equipment designed by Bosch.
  • End-of-line testing was carried out following precise OE criteria. It has been tested to the max, which allows us to rest knowing you will be more than satisfied with the excellent quality of the remanufactured injector.
  • Because the injector meets all OE performance requirements and emission requirements, you are guaranteed an injector that doesn’t cause concerns over emissions.
  • The rail injector you will get has been remanufactured with the latest upgrades to components and specifications.
  • All DFI injectors are built according to OEM specifications.
  • Direct Replacement
  • 1-year Unlimited Mileage Warranty

Are you looking for the highest quality diesel engine replacement parts? Our ASE Certified Technicians can help you get the right parts for your engine! Call us at (855) 212-3022, or you can pick it up yourself.

Our service is located at 1800 South Wenona St., Bay City, MI 48706. It can be easily reached from Bay City, Midland, Saginaw, Flint, Michigan, Mid-Michigan, Central Michigan, and the Great Lakes Bay Region.

Black Engine Smoke In Cummins ISB? Common Rail Fuel Injector Failure Symptoms

Black engine smoke in your Cummins ISB diesel engine could be a result from common rail injector failure.

We’re taking you through this problem so you can better understand what’s going on in your engine, and so that you can prevent these problems in the future!


Need more information on common rail fuel injectors? Call the DFI phone number (855) 212-3022 or stop by our location in Bay City, Michigan.

Why Do I Have Black Exhaust Smoke Coming From My Cummins ISB?


Black smoke is most commonly associated with failing fuel injectors. This occurs when the air-to-fuel ratio is not balanced, and there’s too much fuel or not enough oxygen.

If you have black smoke, your truck is not getting the fuel mileage that it should. Simple as that.

If there’s a mechanical fault in your engine, and you don’t get enough air, combustion won’t be able to occur properly. Improper burning means the fuel doesn’t burn completely, resulting in that thick black smoke coming out of your exhaust.

What Kind Of Mechanical Problems Are Indicated By Black Smoke?

  • Faulty Fuel Injectors
  • Fuel Injectors Sticking
  • Bad Injection Pump
  • Bad Air Filter
  • Bad EGR Valve

Diesel Engine Part Options For Your Cummins ISB Common Rail Injector

5256034 | Genuine Bosch Cummins ISB Common Rail Fuel Injector, Remanufactured

Why Buy From DFI?

  • At DFI, we don’t sell inferior fuel injectors from discount suppliers. We only sell you the best quality fuel injectors for your needs, at fair, affordable prices. Not only that, we’re a reputable, OE-Certified remanufacturing facility with over 40 years experience.
  • Our expert technicians solve virtually any diesel fuel system problem, offer you a fast and accurate estimate, and provide expert repair and installation advice, so you can make a confident purchasing decision.
  • We know that you need to get parts fast to service your customers. That’s why we at DFI make sure that we have readily available fuel system parts for your specific diesel engine and can typically ship your parts the same day.
  • Our injectors are remanufactured to the highest quality standards, with upgraded parts that meet or exceed OEM specifications. Parts are tested using the latest OE-approved diagnostic testing equipment and technology.
  • All wearable components are replaced with new OE parts and meet the latest emissions requirements.

White Engine Smoke In Cummins ISB? Common Rail Fuel Injector Failure Symptoms

White engine smoke in your Cummins ISB diesel engine could be a result from common rail injector failure.

We’re taking you through this problem so you can better understand what’s going on in your engine, and so that you can prevent these problems in the future!


Need more information on common rail fuel injectors? Call the DFI phone number (855) 212-3022 or stop by our location in Bay City, Michigan.

Why Do I Have White Exhaust Smoke Coming From My Cummins ISB?


White smoke is a result of fuel or coolant that isn’t burning correctly. This can be because of too much fuel in the combustion chamber, or the fuel just isn’t burning right. One of the tell-tale signs of unburnt fuel leaving your exhaust pipe is the smell of rich diesel fuel.

If you’re experiencing white smoke in your Cummins engine, you could have an issue with a worn out injector. Another issue you may have is an injector with a cracked tip, or even problems with your solenoid.

Other reasons you’re experiencing white smoke may include lack of compression, or possibly coolant entering your combustion chamber.

What Kind Of Problems Are Indicated By White Smoke?

  • Worn Out Injector
  • Fuel Injectors Sticking
  • Cracked Tip
  • Solenoid Issues
  • Harness Issues
  • Poor Fuel Quality
  • Coolant In Combustion Chamber
  • Water In Combustion Chamber

Diesel Engine Part Options For Your Cummins ISB Common Rail Injector

3973059 | Genuine Bosch Cummins ISC Common Rail Injector, Remanufactured


Why Buy From DFI?

  • At DFI, we don’t sell inferior fuel injectors from discount suppliers. We only sell you the best quality fuel injectors for your needs, at fair, affordable prices. Not only that, we’re a reputable, OE-Certified remanufacturing facility with over 40 years experience.
  • Our expert technicians solve virtually any diesel fuel system problem, offer you a fast and accurate estimate, and provide expert repair and installation advice, so you can make a confident purchasing decision.
  • We know that you need to get parts fast to service your customers. That’s why we at DFI make sure that we have readily available fuel system parts for your specific diesel engine and can typically ship your parts the same day.
  • Our injectors are remanufactured to the highest quality standards, with upgraded parts that meet or exceed OEM specifications. Parts are tested using the latest OE-approved diagnostic testing equipment and technology.
  • All wearable components are replaced with new OE parts and meet the latest emissions requirements.