Bad diesel injectors can cause all sorts of problems with your vehicle. Not only will it affect performance, but it can also lead to expensive repairs if not taken care of.
This article will discuss the symptoms of bad diesel injectors and how to diagnose and clean them if necessary.
A few key symptoms will let you know if you have a bad diesel injector. First, your engine may run rough or misfire. You may also notice a loss in power, increased fuel consumption, or black smoke from the exhaust.
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What are Diesel Fuel Injectors?
Diesel fuel injectors are a fuel injection system found in diesel engines. They are responsible for matching the correct amount of diesel fuel to each cylinder to carry the combustion process necessary for power generation in the vehicle’s engine.
Injectors are also responsible for creating a spray pattern evenly distributing the fuel throughout the combustion chamber.
Diesel engines need more fuel than gasoline engines because they run at a higher compression ratio. This means that there is more pressure in the cylinders when the piston is at the top of its stroke than in a gasoline engine.
This higher pressure creates more heat, which ignites the fuel and makes the engine run. Diesel fuel is more difficult to ignite than gasoline, so it needs a higher compression ratio to get the engine going.
The diesel fuel injector is designed to withstand the high pressures in the engine. It is made of strong metals and has seals that prevent leaks. The injector is also designed to deliver the right amount of fuel for the engine’s speed.
The computer controls the injector, so it opens and closes at the right time for the engine speed. This ensures that the engine gets enough fuel for efficient operation via the fuel system.
How Does a Diesel Fuel Injector Work?
The injector is usually controlled by a solenoid or a pressure-activated plunger, which allows the injector to open and close. As the plunger opens, diesel fuel is forced through a small nozzle under high pressure. This high-pressure stream of diesel fuel penetrates the cylinder head and enters the combustion chamber.
The diesel fuel injector has to deliver the right amount of fuel at the right time for the engine to run properly. If too much fuel is injected into the engine, it will run “rich” and may stall or hesitate. If too little fuel is injected, the engine will run “lean” and may also stall or hesitate.
Diesel fuel injectors are designed to open and close very quickly, usually in less than 1/1000 of a second. This quick opening and closing allow the injector to deliver a precise amount of diesel fuel into the engine.
This opening and closing are governed by the engine’s computer, which determines how much fuel is needed based on various factors such as engine speed, load, and temperature.
Symptoms of Bad Diesel Injector
As mentioned earlier, a few key symptoms will let you know if you have bad fuel injectors. Which includes:
- Check Engine Light
- Car’s Engine Won’t Start
- Increased Fuel Consumption
- Engine Stalling
- Diesel Smell Inside Cabin
- Increased Emission
- Engine Misfire
- Unburnt Fuel from Exhaust Pipe
- Engine Sputtering
For the sake of understanding, we will briefly touch on these bad fuel injector symptoms.
1. Check Engine Light:
One of the first signs that something is wrong with your diesel injector is when the check engine light comes on.
This warning light can indicate a variety of different problems. Still, if it’s accompanied by any other symptoms on this list, it’s likely that your injector has an issue.
2. Car’s Engine Won’t Start:
If you try to start your car and the engine won’t turn over, there could be a problem with your diesel injector. In some cases, the car starts but immediately dies after that.
When the injector is not working properly, it can prevent the engine from getting the fuel it needs to start. If this is the case, you’ll likely need to have your injector repaired or replaced.
3. Increased Fuel Consumption:
If you notice that your car is suddenly using more fuel than it did before, it could be due to a problem with the injector.
When the injector is not working properly, it can cause the engine to use more gas mileage tanks than it should. This can lead to an increase in your fuel bill and may require you to fill up your tank more often than usual.
If you notice the poor fuel economy of your truck, it’s important to have your car checked out by a mechanic as soon as possible.
4. Engine Stalling:
If your engine stalls frequently, it could be a sign that there’s an issue with your diesel injector.
A dirty diesel fuel injector can cause engine stalls in a number of ways. First, the build-up of deposits on the injector can restrict fuel flow, causing a drop in pressure and a loss of power.
Second, the deposits can act as an insulator, preventing the electrical current from reaching the injector tip and firing the injector.
Finally, the deposits can physically block the injector from opening, preventing fuel from entering the cylinder. Any of these problems can lead to engine stalls.
5. Diesel Smell Inside Cabin:
If you notice a diesel smell inside your car’s cabin, it’s likely that there’s a problem with your injector.
Diesel fuel can leak from the injector due to several different issues. A cracked injector body, damaged O-rings, or a loose connection can all cause diesel fuel to leak from the injector.
This leaking fuel can then make its way into the car’s cabin, where you’ll be able to smell it.
6. Increased Emission:
Bad diesel injectors can also lead to increased emissions from your car. When the injector is not working properly, it can cause the engine to run rich, which means that too much fuel is injected into the engine.
This can lead to an increase in the number of harmful emissions coming from your car’s exhaust.
7. Engine Misfire:
Another symptom of bad diesel injectors is engine misfire. When the injector is not working properly, it can cause the engine to misfire or hesitate while running.
The diesel engine entirely relies on timely fuel injection for its proper functioning since there is no spark plug to create a spark. If the injector fails to deliver the right amount of fuel at the right time, it can cause the engine to misfire.
An engine misfire can lead to a loss of power and decreased fuel efficiency.
8. Unburnt Fuel from Exhaust Pipe:
If you notice unburnt fuel coming from your car’s exhaust pipe, there is likely an issue with your injector.
When the injector is not working properly, it can cause the engine to run rich, which means that too much fuel is injected into the engine.
This excess fuel then exits the exhaust pipe unburned and can be seen as a black sooty substance.
9. Engine Sputtering:
Engine sputtering is another symptom of bad diesel injectors. When the injector is not working properly, it can cause the engine to run lean, which means that there’s not enough fuel being injected into the engine.
This can lead to a loss of power and decreased fuel efficiency. Additionally, you may notice that your car’s engine is making a popping or sputtering noise when this happens.
Why is Your Diesel Injector Malfunctioning?
There are several reasons a diesel injector may malfunction, and it is important to be aware of these potential issues to keep your engine running smoothly.
One reason for diesel injector failure is improper fuel delivery. If the fuel delivery system is not working correctly, the injectors will not receive the correct amount of fuel. This can lead to premature wear or damage to the injectors and eventually cause them to fail.
Another reason for injector failure is the deposits that build up on the injectors over time. These deposits can restrict fuel flow and prevent the injectors from working properly. The reason behind the formation of these deposits is the use of low-quality diesel fuel, which contains impurities that can build up on the injectors.
The high temperatures inside the engine can also cause problems for the injectors. The heat can damage the seals and O-rings that are used to keep fuel from leaking out of the injectors. If these seals are damaged, fuel can leak into the engine, causing a loss of power and decreased efficiency.
A malfunctioning fuel rail pressure sensor is often the root cause of injector failure. The pressure sensor is responsible for sending a signal to the computer that controls the injectors, telling it how much fuel to deliver.
If the pressure sensor is not working correctly, the computer will not be able to deliver the correct amount of fuel to the engine, causing the injectors to fail.
There are several reasons why a diesel injector may malfunction, and it is important to be aware of these potential issues in order to keep your engine running smoothly.
How to Clean Dirty Fuel Injectors?
Clogged injectors are a common problem in many vehicles. Over time, deposits can build up on the injectors, causing them to become clogged and less effective.
Fortunately, cleaning dirty fuel injectors is a relatively simple process that can be done at home with the right tools and supplies.
- Disconnect the negative battery cable.
- Remove the plastic engine cover if equipped.
- Locate the fuel injectors on the engine. In most cases, they will be located near the intake manifold.
- Using a fuel line disconnect tool, disconnect the fuel lines from the injectors.
- Unplug the electrical connectors from the injectors.
- Remove the fuel injector retaining clip or bolts (depending on your vehicle) using a socket wrench or screwdriver.
- Carefully pull out the dirty fuel injector from its housing. Avoid touching the O-ring seal as it can easily become damaged.
- Soak the fuel injectors in a cleaning solution designed specifically for this purpose.
- Use a brush to clean away any caked-on deposits from the injectors.
- Rinse the fuel injectors with clean water and dry them with a lint-free cloth.
- Now start with the installation process.
- Inspect the O-ring seal on the fuel injector for any damage or wear. If it is damaged, replace it with a new one before proceeding.
- Coat the new O-ring seal with some fresh engine oil and fit it onto the fuel injector.
- Insert the fuel injector back into its housing and secure it in place with the retaining clip or bolts.
- Reconnect the electrical connector to the fuel injector.
- Repeat these steps for each of the remaining fuel injectors.
- Close the hood of your car once you have finished installing all the fuel injectors.
- Start the engine and let it idle for a few minutes. Check for any leaks around the injectors. If there are no leaks, you’re done!
Diesel Fuel Injector Replacement Cost
The cost of replacing a diesel fuel injector can vary depending on your vehicle’s make, model, and number of injectors.
In most cases, you can expect to pay between $600 and $1200 for replacing all injectors in your vehicle. However, some vehicles may require special tools or parts that can increase the cost of the job.
Bad diesel injectors can cause several problems for your vehicle, from decreased performance and fuel efficiency to engine damage.
Fortunately, there are several ways to clean dirty fuel injectors and prevent them from going bad in the first place.
If you think your vehicle may have bad diesel injectors, be sure to take it to a qualified mechanic or service center for diagnosis and repair.
Replacing all the injectors in your car can be expensive, but it is often necessary to keep your engine running smoothly.
I hope this article has been helpful in understanding the symptoms of bad diesel injectors and how to clean them.
If you have any further questions, please feel free to contact us at any time. Thank you for reading!
Frequently Asked Questions
What is the average life expectancy of a diesel injector?
The average life expectancy of a diesel injector is around 50,000 miles. However, this can vary depending on the make and model of your vehicle as well as your driving habits.
What does a faulty diesel injector sound like?
A faulty fuel injector may sound like a ticking noise from the engine. This is caused by the injector opening and closing rapidly as it tries to deliver fuel to the engine. Or, in some cases, you might hear a knocking noise caused by the fuel not being burned properly in the cylinders.
What happens when an injector goes bad?
Bad diesel injectors can cause several problems for your vehicle, from decreased performance and fuel efficiency to engine damage. In some cases, the engine may not start at all if one or more of the injectors are completely clogged.
How to test a bad fuel injector?
If you think you may have a bad fuel injector, there are a few tests you can perform to confirm this. One way is to check the engine’s compression. If the compression is low, it’s likely that one or more of the injectors is not working properly.
Another test is to check the fuel pressure at the rail. If the pressure is lower than normal, it could be due to a faulty injector.
How long can you drive with a faulty fuel injector?
It would depend upon the severity of the problem. If an injector is only partially clogged, you may be able to drive for a short distance without any issues. However, if an injector is completely clogged, it will not be able to deliver any fuel to the engine, and the vehicle will not run.
Hence, you may be able to squeeze out a few hundred or even a few thousand miles before total failure. But, it is not recommended to drive with a faulty fuel injector for too long as it can cause serious engine damage.