If you are alert of abnormal symptoms on your car, you are right to be concerned, because a car represents a big annual budget and surprising breakdowns don’t reduce the bill. So what if you feel like you have a leaking injector on your Mercedes Classe S? You probably figured it out thanks to black/oily drips along your engine unit, or a troubled idle, or strange black smoke. These three manifestations are the main signals of a leaking injector. As this problem can cause more serious engine concerns on your car, we chose to produce this article content to help you ensure the failure of a leaking injector and handle it properly. To do this, we will first of all look into the case of gasoline injectors and then at those of diesel injectors Mercedes Classe S.

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Leaking injector on my petrol Mercedes Classe S

It is crucial to know that the injectors on petrol and diesel engines are different, actually, the difference in combustion between these two kind of engines makes the injection different. 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 Mercedes Classe S: The different leaks

It should be known that injector leaks on a Mercedes Classe S equipped with a petrol engine are rather infrequent. This is due to the much lower pressure in the petrol intake systems. However, there are two kind 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 connected 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 part of the injector of your car, this one will occur from the junction with the engine and not with the rail as seen before.

Leaking injector on my diesel Mercedes Classe S

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 Mercedes Classe S: The different leaks

In the case of leaking diesel injectors on your Mercedes Classe S, there are three several kind of leaks:

  • Leakage from the injector inlet:
    In cases like this, it is an inlet pipe that will deform over time, generally 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 Mercedes Classe S 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 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 examining you have oil leaking but it does not come from your injectors, we encourage you to browse this article content on the presence of oil leaking on your Mercedes Classe S.

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

And finally, we’re going to look into 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 due to the pressures suffered. But think that the pressure in the circuit is gigantic, especially on diesel engines. So you will have to take some precautions:

  • Lower the pressure before any work is conducted…
  • 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 restricted to replacing 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 specifically complex, but if you have the slightest doubt in the treatment of your injector that leaks on your Mercedes Classe S, we encourage you to get closer to your mechanic to avoid any bad handling that could seriously harm the condition of your Mercedes Classe S.

If you wish more tutorials on the Mercedes Classe S, go to our Mercedes Classe S category.