In cases where you are informed of irregular signs on your automobile, you are right to be concerned, because a car represents a huge annual budget and unpredicted malfunctions don’t lower the expenses. So what if you sense that you have a leaking injector on your Audi A3? You almost certainly figured it out thanks to black/oily drips along your engine, or a disturbed idle, or strange black smoke. These three manifestations are the main signals of a leaking injector. As this failure can end up in more significant engine trouble on your car, we made a decision to write this content page to help you validate the failure of a leaking injector and treat it correctly. To do this, we will initially look into the case of gasoline injectors and then at those of diesel injectors Audi A3.


Leaking injector on my petrol Audi A3

It is fundamental to know that the injectors on petrol and diesel engines are distinct, in fact, the difference in combustion between these two sort of engines makes the injection distinct. The biggest difference lies in the pressure experienced 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 Audi A3: The different leaks

It should be known that injector leaks on a Audi A3 equipped with a petrol engine are pretty rare. This is resulting from the much lower pressure in the petrol intake systems. However, there are two sort of leaks:

  • Leakage from the top of the injector:
    It is conceivable that you have a leak from the top of the injector, this is the component that is linked to the fuel rail, an O-ring will be involved in this.
  • Leak injector of the lower part:
    At last, you may encounter 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 sooner.

Leaking injector on my diesel Audi A3

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 Audi A3: The different leaks

In the case of leaking diesel injectors on your Audi A3, there are three several sort of leaks:

  • Leakage from the injector inlet:
    In cases like this, 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 implies, this leakage concerns the management of the fuel return in the injector, this time the injector that leaks on your Audi A3 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 encounter 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 content page on the existence of oil leaking on your Audi A3.

Leaking injector on my Audi A3, how to fix the leak

And finally, we’re going to look into how to fix a leaking injector on your car. Oftentimes a leak is associated, as we have seen prior to this, 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 measures:

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

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

  • Find the source of the leak
  • Take apart the injector in question
  • Replace the corresponding seal kit
  • Reassemble the set up and tighten with a torque wrench in respect with the manufacturer’s standards.

In all cases, these interventions are not specifically very hard, but if you have the tiniest doubt in the treatment of your injector that leaks on your Audi A3, we advise you to get closer to your repair shop to avoid any bad manipulation that could seriously harm the condition of your Audi A3.

If you want more tutorials on the Audi A3, go to our Audi A3 category.