Clean diesel in injector wells

[ForumGuru]

Greetings to everyone

I saw a little leak on the drive underneath the engine, and I am aware that it is diesel. I removed the engine cover and saw that, despite its cleanliness, there is a little accumulation of diesel around the injector seats. I cleaned it with paper towels, and it is entirely free of liquid and carbon buildup. I have also seen that the two rear injectors exhibit more deterioration, but the front injector shows no diesel leakage around it.

I suspect that the little fuel return lines connecting to the injectors may be leaking, however I cannot see any visible leakage. The upper portions of the rear two injectors seem little moist; may this indicate an issue with the return lines? Resulting in the appearance of moisture on the injector tops?

I have a potentially unrelated issue: a loud fuel pump producing a gurgling sound when the ignition is on but the engine is not started. I have seen many postings indicating that somebody overcame this issue by substituting the return lines. If the little O-rings fail, they let air to enter the system at this juncture, resulting in the noise.

Any assistance or insights about this matter would be welcomed.

[bvlenci]

It is referred to as a leak-off pipe, and a repair version is available from MB. It is quite probable that this is the source of the leak.

[ForumGuru]

Thank you for your response. I have seen many discussions in which individuals have substituted the leak-off pipe; however, Mercedes-Benz does not provide a connection for attachment to the remaining piping. Which connection would be optimal for this application?

[bvlenci]

Are you certain they do not? I am quite certain they have a repair section.

[Matt865]

A fractured nozzle holder cap may result in leakage at the injector foot, perhaps leading to subsequent black death. Rear wells are inferior due to the drain line's positioning towards the rear of the engine, which I suspect is somewhat slanted.

[ForumGuru]

I suspect that the persistent dampness at the top of the injector, after having wiped it off yesterday, indicates a potential issue with the leak-off line.

[ForumGuru]

I contacted them today. Regrettably, they provide just the pipe, without a connection. Is a plastic straight push-fit fuel line connection suitable for this application? Assuming its low pressure on the return side.

[bvlenci]

I believe that is the case.

[Paqngo]

I would use white spirit for cleaning, while intently observing the engine in operation to ascertain the source of the leak.

The picture shows the leak-off push-in without its 'O' ring.
During the engine reconstruction, mine was leaking at a 'O' ring. Substitutes are accessible.
Exercise caution; my new 'o' rings were somewhat challenging to reinsert, ensuring that the push-in retainers would engage properly. The breakage was effortless.