Whenever you are alert of unusual symptoms on your car, you are right to be concerned, because a car represents a huge annual budget and unforeseen malfunctions don’t reduce the costs. So what if you sense that you have a leaking injector on your BMW 3 Series? You most likely figured it out thanks to black/oily drips along your engine motor, or a troubled idle, or uncommon black smoke. These three manifestations are the main symptoms of a leaking injector. As this troubles can end up in more significant engine complications on your car, we made a decision to compose this content to help you verify the failure of a leaking injector and treat it properly. To do so, we will first of all check out the circumstance of gasoline injectors and then at those of diesel injectors BMW 3 Series.


Leaking injector on my petrol BMW 3 Series

It is fundamental to know that the injectors on petrol and diesel engines are distinct, in reality, the difference in combustion between these two types of engines makes the injection distinct. The essential 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 3 Series: The different leaks

It should be said that injector leaks on a BMW 3 Series equipped with a petrol engine are rather rare. This is caused by the much lower pressure in the petrol intake systems. Nevertheless, there are two types 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 connected to the fuel rail, an O-ring will be involved in this.
  • Leak injector of the lower part:
    At last, you may experience a leak coming from the lower portion of the injector of your car, this one will come from the junction with the engine and not with the rail as seen before.

Leaking injector on my diesel BMW 3 Series

Unlike petrol engines, which have spark combustion, diesel engines run on compression. This combustion system produces 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 3 Series: The different leaks

In the circumstance of leaking diesel injectors on your BMW 3 Series, there are three several types of leaks:

  • Leakage from the injector inlet:
    In this instance, it is an inlet pipe that will deform as time passes, usually the leak will be at the clamping point.
  • Injector return leakage:
    As its name reveals, this leakage relates to the management of the fuel return in the injector, this time the injector that leaks on your BMW 3 Series will be the result of 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 feel an air noise and a compression loss.
  • If after checking you have oil leaking but it does not come from your injectors, we recommend you to consult this content on the existence of oil leaking on your BMW 3 Series.

Leaking injector on my BMW 3 Series, how to fix the leak

And finally, we’re going to check out how to fix a leaking injector on your car. Very often a leak is connected, as we have seen prior to this, to a worn seal caused by the pressures suffered. But think that the pressure in the circuit is tremendous, especially on diesel engines. So you will have to take some safety measures:

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

Relating to the repair part of your leak, it will frequently be restricted to replacing the seals that have failed:

  • Identify 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 accordance with the manufacturer’s standards.

In all situations, these interventions are not inevitably complicated, but if you have the tiniest uncertainty in the treatment of your injector that leaks on your BMW 3 Series, we recommend you to get closer to your motor mechanic to avoid any bad handling that could significantly harm the condition of your BMW 3 Series.

If you want more guides on the BMW 3 Series, go to our BMW 3 Series category.