Leaking injector on my Mercedes Classe A 4, what to do ?

In the event you are aware of abnormal signs on your vehicle, you are right to be preoccupied, because a car represents a big annual budget and unpredicted malfunctions don’t reduce the bill. So what if you feel like you have a leaking injector on your Mercedes Classe A 4? You probably figured it out thanks to black/oily drips along your engine unit, or a troubled idle, or abnormal black smoke. These three symptoms are the main indicators of a leaking injector. As this failure can bring on more significant engine complications on your car, we chose to write this content to help you confirm the failure of a leaking injector and deal with it correctly. To achieve this, we will initially look at the case of gasoline injectors and then at those of diesel injectors Mercedes Classe A 4.

Leaking injector on my petrol Mercedes Classe A 4

It is fundamental to know that the injectors on petrol and diesel engines are different, the truth is, the difference in combustion between these two types of engines makes the injection different. The main 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 Mercedes Classe A 4: The different leaks

It should be known that injector leaks on a Mercedes Classe A 4 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 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 part 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 portion of the injector of your car, this one will come from the junction with the engine and not with the rail as seen sooner.

Leaking injector on my diesel Mercedes Classe A 4

Unlike petrol engines, which have spark combustion, diesel engines run on compression. This combustion system 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 Mercedes Classe A 4: The different leaks

In the case of leaking diesel injectors on your Mercedes Classe A 4, there are three several types of leaks:

  • Leakage from the injector inlet:
    In this case, it is an inlet pipe that will deform with time, usually the leak will be at the clamping point.
  • Injector return leakage:
    As its name implies, this leakage relates to the management of the fuel return in the injector, this time the injector that leaks on your Mercedes Classe A 4 will be a consequence 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 experience an air noise and a compression loss.
  • If after examining you have oil leaking but it does not come from your injectors, we advise you to read this content on the existence of oil leaking on your Mercedes Classe A 4.

Leaking injector on my Mercedes Classe A 4, how to fix the leak

And to finish, we’re going to look at how to fix a leaking injector on your car. Very often a leak is connected, as we have seen previously, to a worn seal because of 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 achieved…
  • 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 very often be restricted to swapping the seals that have failed:

  • Situate the source of the leak
  • Dismantle 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 situations, these interventions are not necessarily very hard, but if you have the tiniest uncertainty in the treatment of your injector that leaks on your Mercedes Classe A 4, we advise you to get closer to your repair shop to avoid any bad handling that could critically harm the condition of your Mercedes Classe A 4.

To get more tips on the Mercedes Classe A 4, take a look at the Mercedes Classe A 4 category.