If you are aware of abnormal signs on your vehicle, you are right to be concerned, because a car represents a huge annual budget and unexpected breakdowns don’t reduce the bill. So what if you feel like you have a leaking injector on your car? You probably figured it out thanks to black/oily drips along your engine, or a disturbed idle, or unusual black smoke. These three symptoms are the main signs of a leaking injector. As this failure can lead to more serious engine problems on your car, we decided to write this article to help you confirm the failure of a leaking injector and treat it properly. To do so, we will first look at the case of gasoline injectors and then at those of diesel injectors cars.

injector leaking on my car

Leaking injector on my petrol car

It is important to know that the injectors on petrol and diesel engines are different, in fact, the difference in combustion between these two types of engines makes the injection different. The main difference lies in the pressure undergone by the injectors, on a petrol engine it will vary between 3.5 bars for indirect injection and 120 bars for indirect injection.

Leaking injector on a petrol car: The different leaks

It should be noted that injector leaks on a car equipped with a petrol engine are rather rare. This is due to the much lower pressure in the petrol intake systems. However, there are two types of leaks:

  • Leakage from the top of the injector:
    It is possible that you have a leak from the top of the injector, this is the part that is connected to the fuel rail, an O-ring will be involved in this.
  • Leak injector of the lower part:
    Finally, you may experience a leak coming from the lower part of the injector of your car, this one will occur from the junction with the engine and not with the rail as seen previously.

leakin injector on my car

Leaking injector on my diesel car

Unlike petrol engines, which have spark combustion, diesel engines run on compression. This combustion system generates very high pressure in the engine, as do the injectors. On these models, the pressure is more than 10 times higher than on the direct injection of car petrol engines, reaching 1800 to 2000 bars.

Leaking injector on diesel car: The different leaks

In the case of leaking diesel injectors on your car, there are three different types of leaks:

  • Leakage from the injector inlet:
    In this case, it is an inlet pipe that will deform over time, usually the leak will be at the clamping point.
  • Injector return leakage:
    As its name indicates, this leakage concerns the management of the fuel return in the injector, this time the injector that leaks on your car will be caused by an O-ring or its plastic tip that leaks.
  • Injector base leak:
    This injection leak is one of the most annoying, it is the junction between the engine and the injector nose that leaks at a copper seal, you should feel an air noise and a compression loss.
  • If after checking you have oil leaking but it does not come from your injectors, we advise you to consult this article on the presence of oil leaking on your car.

Leaking injector on my car, how to fix the leak

And finally, we’re going to look at how to fix a leaking injector on your car. Very often a leak is linked, as we have seen previously, to a worn seal due to the pressures suffered. But think that the pressure in the circuit is enormous, especially on diesel engines. So you will have to take some precautions:

  • Lower the pressure before any work is done…
  • Covering you to avoid the risk of fuel spillage
  • NEVER work on a running diesel engine injector.

Concerning the repair part of your leak, it will very often be limited to changing the seals that have failed:

  • Locate the source of the leak
  • Dismantle the injector in question
  • Replace the corresponding seal kit
  • Reassemble the assembly and tighten with a torque wrench in accordance with the manufacturer’s standards.

In all cases, these interventions are not necessarily difficult, but if you have the slightest doubt in the treatment of your injector that leaks on your car, we advise you to get closer to your mechanic to avoid any bad handling that could seriously harm the condition of your car.