Common Rail Diesel Problems (Here Is How To Solve)

Common Rail Diesel Problems

Common rail is the most popular fuel injection system for diesel vehicles. However, it is a system that has problems. Some rather serious problems, in fact.

It can actually be quite tricky to fix many of them. While preventative maintenance is always your best bet, we understand that many people don’t do that.

So, on this page, we want to go through some of the more common issues with the common rail and teach you how to fix them.

How Do You Know You Have An Issue With Your Common Rail?

This is pretty much the golden question. Truth be told, you can never be 100% sure that you have an issue with the common rail in your vehicle. Not unless you are a mechanic.

This is because there are a lot of things in an engine that can cause issues, and often the symptoms are going to be very much the same.

If you are dealing with any of the following, then there is a strong chance (but no guarantee) that you have an issue with your common rail:

  • Excess smoke from your vehicle (the exhaust should be putting out vapor, not smoke)
  • Engine rattling
  • Struggling to start the vehicle, particularly in colder conditions.
  • The vehicle doesn’t start at all
  • The check engine light is coming on.
  • You may sometimes feel a loss of power in the engine.
  • The engine chugs a lot, particularly if you have been driving for a while.

When you have an issue with your common rail, at least in a modern vehicle, the vehicle will record an error code onto the system’s onboard computer.

If you take your vehicle to a mechanic, they will be able to read the error code and determine the issue.

Remember, the whole job of a common rail is to feed fuel into the engine. This means that if you do have any issues with the fuel injection system, then it means fuel isn’t going to be flowing as efficiently into the engine.

You will notice this when you drive the vehicle. Once again, we do want to point out that this does not necessarily guarantee that you have an issue with your common rail, but it does strongly indicate it.

Almost all of the issues with a common rail system will have been caused by excess debris build-up on the system.

This means that your best bet, as we said, is preventative care. If you can prevent that build-up in the first place, then the chances are high that you would never have to deal with any issues related to your common rail fuel system. 

Use The Right Fuel

Due to the way in which common rail works, the system is much more prone to issues with fuel quality.

If you are noticing a lot of issues with smoke, engine rattling, deposits, etc. then it may actually be worth switching up the fuel that you use. Always opt for the best quality fuel that you can afford. Yes, it is going to be a bit more expensive.

However, you have to remember that having a broken common rail is going to cost you a whole lot more later on. This is why preventative maintenance is so expensive.

Luckily, finding the right fuel shouldn’t be too tricky. However, we do tend to recommend that people buy their diesel fuel from larger gas stations that get a lot of use.

This is because when fuel is stuck in a gas station for too long, its quality will start to degrade. If the quality of a fuel starts to degrade, then this is going to impact your fuel injectors.

Change Your Diesel Engine Oil

This is another job that you should already know how to do. It is always worth knowing how to switch out the engine oil on your vehicle because it is something that is going to need to be done every six months. Trust us. You will save a whole lot of cash being able to do this yourself!

Your vehicle’s manual will walk you through how to change your engine oil. This is especially important because, over time, your diesel engine oil will start to collect all sorts of contaminants.

This is something that will end up impacting the movement of the fuel injectors which, of course, can have an impact on how your vehicle functions.

Dealing With Sticking Fuel Injectors 

If you have sticking fuel injectors, then you will be pleased to know that you can purchase fuel injector cleaning kits.

We do suggest that you read through your vehicle’s operating manual here, just so you can be 100% sure that you are targeting the fuel injectors.

It is worth noting that this can be quite a dangerous job, mostly because the cleaning kit solutions are flammable. So, don’t do this if you are not 100% sure what you are doing.

A fuel injector cleaning kit will come with hoses, cleaning solution, etc. and it will tell you exactly how to clean the fuel injectors (it will vary between kits and vehicles).

Essentially, with a fuel injector cleaning solution, you are going to be pumping cleaning solution through the system, much like you would be pumping fuel through the system (never let the fuel and cleaning solution come into contact with one another!) and this should remove any debris build-up, which is a common issue with common rail fuel injection systems.

If you are going to be using this method to clean your fuel injectors, then we suggest that you carry out a complete engine oil change at the same time.

This is because if there is enough build-up on the fuel injectors to cause them to stick, then it means that there is a lot of debris in the system. This is something that could have easily contaminated the fuel. 

When To Visit a Garage

As we said, this is a very quick guide to fixing common rail diesel problems. We understand that many problems can be quite tough to solve.

This is why, in most cases, we recommend that people reach out to a mechanic. If you have absolutely no experience fixing vehicles, then a mechanic is always going to set you on the right path. it will save you a whole lot of trouble trying to establish the issue too.

To be honest, since most common rail diesel problems involve you tinkering about with your engine, it probably isn’t something that you would want to fix yourself anyway.

It is all well and good changing the fuel that you use or even changing your engine oil, but when it comes to playing about with vehicle components, this is always going to be something that is best left in the hands of somebody much more capable. 


Most common rail diesel problems can’t really be solved yourself. This is because a common rail fuel injection system can be quite intricate.

Outside of cleaning the fuel injectors, switching out the engine oil, or changing the fuel that you use, this is probably a job that should be left in the capable hands of a professional.


Steve P.

Steve is an automotive technician, technical writer, and Managing Editor. He has held a lifelong passion for cars, with a particular interest in cars like the Buick Riviera. Steve is based in Boise, Idaho.

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