Why Do Diesel Injectors Fail?

There are two basic reasons why diesel injectors fail. The first is concerned with the injector’s mechanical integrity, while the second is concerned with the quality of the gasoline passing through it. Exergy Engineering was approached in order to gain a better knowledge of how injectors work (and what causes them to fail). Many of the photographs of failed injectors you see here were captured with a microscope by the company to assist you in preventing this damage to your diesel.

What happens when a diesel injector fails?

The fuel injection system is an important part of any diesel engine. The fuel is pressurized and injected into compressed air in the combustion chamber via this system. Feeding fuel to the injectors, regulating the fuel supply, modifying the injection time, and atomizing the fuel are all operations of a fuel injection system.

The proper amount of fuel, at the right time, in the right condition for combustion, must be delivered.

Fuel injectors help enhance fuel efficiency, reduce the need for fuel system maintenance, and keep emissions cleaner. A diesel fuel injector has an average lifespan of 100,000 kilometers. The nozzle and the injector body are the two primary elements of a standard fuel injector. If either of these components becomes clogged or destroyed, the vehicle’s overall performance is jeopardized.

  • Uneven idling or difficulty starting the car. The engine cranks, but it won’t start unless you crank it hard enough. On idle, the engine uses a variety of rev levels.
  • Misfire. A full diagnostic of a vehicle that is misfiring on ignition entails determining which component of the combustion process is missing. This is caused by either a lack of fuel injection or a lack of combustion chamber heat in a diesel engine. One of the cylinders’ fuel charge fails to ignite, or the fuel supply to the ignition system is insufficient.
  • There’s a strong odor of gasoline. The scent of diesel within the cabin indicates that there is a leak. This could be caused by a malfunctioning injector that allows fuel to leak out while it isn’t in use.
  • Emissions are filthy. Filters that are clogged and deposits on injectors create an uneven or partial fuel burn, resulting in a polluted environment around the exhaust and the discharge of white smoke from the exhaust pipe.
  • Fuel consumption has increased, while miles per gallon has decreased. Faulty injectors waste more fuel and have a direct impact on the performance and efficiency of your vehicle.

Clean fuel injectors are essential for your diesel engine to run at its best. Any of the following signs could suggest an issue with your fuel injectors, which should not be overlooked. Injectors that are unclean, clogged, or leaky are examples of this. If you’ve driven your car for more than 100,000 miles without replacing the fuel injectors, it’s time to have them looked at by a specialist.

How often should diesel injectors be replaced?

Diesel fuel injectors have a shorter lifespan than their predecessors, requiring more frequent replacement to maintain peak performance. A decent quality diesel fuel injector has a life expectancy of roughly 150,000 kilometers. Around this time, they should be checked out by a specialist.

What causes injectors to go bad?

Fuel injectors are nothing more than solenoids, which are cylindrical coils of wire that act as magnets and transport an electrical current and actuate pistons very quickly as part of the engine’s fuel delivery system. It takes a high-pressure mist of gasoline and sprays it into the engine, all under the direction of the car’s internal computer. The computer controls the amount of gasoline dispersed as well as the precise time. One fuel injector per cylinder is standard on most vehicles and light trucks with internal combustion engines. The injectors could fire millions of times over the duration of the vehicle’s life!

Previously, automobiles were built with fuel sprayed into the upper intake manifold to mix with air before being ignited in the combustion chamber. Manufacturers eventually switched to one injector per cylinder fuel injection, where fuel is delivered into the lower intake manifold right behind the intake valve. Many automakers have switched to direct injection in recent years. Instead than using the intake manifold, direct injection injects fuel directly into each cylinder. Direct fuel injection systems emit less pollutants, are more powerful, and efficiently deliver gasoline. Direct injection, on the other hand, is more expensive due to more expensive parts and higher fuel consumption. As a result, while the car uses fuel more effectively, it still consumes a significant quantity.

What are the Signs of a Bad Fuel Injector?

The development of impurities such as carbon causes fuel injectors to malfunction. Carbon buildup might result in a clogged or partially clogged injector, preventing it from fully closing. This causes a leak, which causes a misfire. Dry, damaged rubber seals or flaws within the injector itself can cause fuel injectors to leak outside. Electrical components of the injector are particularly susceptible to aging, heat, and moisture damage. Failure manifests itself in the following ways:

  • Misfires caused by a lack of fuel – Misfires are perceptible occurrences that happen while the engine is operating and are usually noticed by a difference in performance or a minor popping sound. The larger the engine, though, the less likely you are to experience a misfire.
  • Lack of power – The engine is unable to provide enough power to keep running.
  • Poor fuel efficiency — Fuel is wasted due to leakage, over-supply, or inability to produce a correct spray pattern for burning.
  • Check engine light on – The check engine light can be triggered by too much or too little fuel provided to the engine.
  • Having trouble starting – The engine is receiving too much or too little fuel. This can also cause the engine to stall or prevent it from starting at all.
  • Fuel Odor — If an injector is leaking, you may notice a gasoline odor while driving.

Any time your car develops a leak, especially a fuel leak, it should be evaluated by a professional as soon as possible. Fuel and fumes leaking from the vehicle’s hood could ignite and cause a fire. A clogged injector does not endanger the vehicle’s safety, but it does starve it of fuel, leading it to operate poorly. Long-term fuel deprivation can cause internal engine damage as well as catalytic converter damage. It’s possible to inspect and test fuel injectors to see whether they need to be changed or cleaned.

Can you drive a car with faulty injectors?

While most fuel injector issues are obvious, driving your car for an extended period of time with a clogged or defective fuel injector can be problematic. Fuel use has increased. The amount of tailpipe smoke and emissions has increased noticeably. Idle is rough, and acceleration is sluggish.

How can you tell if a diesel injector is bad?

So, how do you check the diesel injectors to figure out what’s wrong? Here are four options to consider:

1. Listen to your engine: A fully functioning injector will make a clicking noise. The appropriate opening and closing of the valve causes this clicking noise. If you don’t hear the clicking sounds, it’s a sign that the injectors aren’t working properly. You can try using a stethoscope to listen for the clicking. If you don’t have a stethoscope, a screwdriver or metal rod can be substituted. While the engine is running, place the tip of the rod or screwdriver on the fuel injector. Then, on the other end, place your ear so that sound can be transmitted. This is a smart strategy to keep your face from coming too close to the running engine.

2. Perform a light test: Turn off the engine but keep the battery charged so that electronic systems like the lights and radio remain operational. Your test light should be connected to the negative battery terminal. Then place the test light’s pointed tip on a small part of the injector’s exposed wire. When you do this, the test light should turn on.

3. Look for leaks by placing a paper towel under the fuel injectors and turning the key on but not starting the engine. The injector is leaking if there is fuel on the paper towels.

4. Have your engine’s emissions checked: If your emissions alter, it suggests something is wrong with your engine, which could indicate an injector problem.

How much does it cost to change diesel injectors?

The cost of replacing your fuel injectors ranges from $350 to $850 on average. The cost range is determined by a variety of things.

  • Smaller vehicles with fewer cylinders and hence less expensive parts will be at the low end of the price range.
  • You will have to pay more for the repair if there are other issues with your fuel system, such as problems with the fuel pump. You may wind up paying far more than the pricing range given above, depending on the specific difficulties.

What are the signs of a bad fuel injector?

The most typical signs of faulty fuel injectors are listed below.

  • The Check Engine Light stays on or flashes. A dirty or faulty fuel injector is one of the engine faults that can cause the check engine light to illuminate or flash.