Whenever you are informed of abnormal symptoms on your automobile, you are right to be preoccupied, because a car represents a huge annual budget and surprising malfunctions don’t lower the costs. So what if you sense that you have a leaking injector on your Bmw Serie 3 E90? You likely figured it out thanks to black/oily drips along your engine unit, or a troubled idle, or strange black smoke. These three symptoms are the main signs of a leaking injector. As this troubles can cause more severe engine concerns on your car, we decided to produce this content page to help you validate the failure of a leaking injector and deal with it properly. To achieve this, we will initially take a look at the case of gasoline injectors and then at those of diesel injectors Bmw Serie 3 E90.


Leaking injector on my petrol Bmw Serie 3 E90

It is vital to know that the injectors on petrol and diesel engines are different, actually, the difference in combustion between these two sort of engines makes the injection different. The key 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 Bmw Serie 3 E90: The different leaks

It should be noted that injector leaks on a Bmw Serie 3 E90 equipped with a petrol engine are pretty infrequent. This is caused by the much lower pressure in the petrol intake systems. Even so, there are two sort of leaks:

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

Leaking injector on my diesel Bmw Serie 3 E90

Unlike petrol engines, which have spark combustion, diesel engines run on compression. This combustion procedure creates 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 Bmw Serie 3 E90: The different leaks

In the case of leaking diesel injectors on your Bmw Serie 3 E90, there are three several sort of leaks:

  • Leakage from the injector inlet:
    In this instance, it is an inlet pipe that will deform as time passes, in most cases the leak will be at the clamping point.
  • Injector return leakage:
    As its name reveals, this leakage concerns the management of the fuel return in the injector, this time the injector that leaks on your Bmw Serie 3 E90 will be brought on by an O-ring or its plastic tip that leaks.
  • Injector base leak:
    This injection leak is one of the most bothersome, it is the junction between the engine and the injector nose that leaks at a copper seal, you should find an air noise and a compression loss.
  • If after verifying you have oil leaking but it does not come from your injectors, we encourage you to read this content page on the existence of oil leaking on your Bmw Serie 3 E90.

Leaking injector on my Bmw Serie 3 E90, how to fix the leak

And finally, we’re going to take a look at how to fix a leaking injector on your car. Frequently a leak is linked, as we have seen prior to this, to a worn seal due to the pressures endured. But think that the pressure in the circuit is monumental, specifically on diesel engines. So you will have to take some measures:

  • Lower the pressure before any work is carried out…
  • 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 frequently be limited to replacing the seals that have failed:

  • Find out the source of the leak
  • Dismantle the injector in question
  • Change the corresponding seal kit
  • Reassemble the set up and tighten with a torque wrench in accordance with the manufacturer’s standards.

In all situations, these interventions are not automatically very hard, but if you have the tiniest hesitation in the treatment of your injector that leaks on your Bmw Serie 3 E90, we encourage you to get closer to your auto technician to avoid any bad handling that could seriously harm the condition of your Bmw Serie 3 E90.

If you want more tutorials on the Bmw Serie 3 E90, go to our Bmw Serie 3 E90 category.