W211 Diesel Injector Leaking Issue

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Speedy55

Member
Joined
Jul 30, 2022
Messages
36
Location
Worcestershire
Car
W212 E220CDI Avantgarde
Hi Huys,
My W211 07 E220CDI at 133.000 miles. I had injector leaking issues at 125.000 miles and went to garage to re-seat the injectors last year.
Mechanic has confirmed that no injector cleaning is required, he has just re-seal and re-seated the injectors.
Approx 6 months later, I had the same issue but I didn't want to go to the same garage.

I found another garage in Worcester. Mechanics removed and re-seated 3 of the injectors a month ago.
Then a couple of days later, I noticed that injector leaking issues still persist and I asked them to re-seat 1st and 3rd injectors.
But they re-seated injector 2
smile.gif

Now, it looks 1, 2 and 4 are ok. But 3rd is leaking as I've complained about it.

tbh, I hate the injector issues of W211 diesels.

Is there a permanent solution or better garage you can advise around Worcester?

Cheers,
 
It shouldn't need an MB specialist as it's a run o the mill task, but I think you should consider it.

If there is leakage than it follows there's a track. Without polishing the seat and cleaning (maybe even replacing) the injector it seems a fair bet recurrence is going to happen.

The greater risk is head damage due to not tightening to correct torque. Although it's possible they were afraid of damage so under torqued.
 
@m80 I believe mechanics afraid of snapping the bolts by overtightening. That's why they're tightening under 15Nm and the injectors keep leaking.
But I'm not sure whether it's a common issue of it's production year.
My wife had Golf mk6 and she had injector issues. Once I took her car to the Bosch injector service, the mechanic has blamed VW as they have preferred Siemens injectors on those years for 2 years. And based on his speech, then VW has started to use Bosch injectors.
I'm wondering if that's the case for my model year or W211 in general.

And what's the best option to fix it permanently? to take my car to the same garage or to one of the diesel injector services as they're experienced on injector replacement and cleaning only?
 
Do you know what they are actually charging you for ? What is their definition of 're seating' ?

Removing the injectors and somehow putting a hone on the sealing surface then fitting new injectors and or seals ? or just taking the old ones out cleaning everything then putting them back in ?

Not sure how the mechanic can say if the injectors 'do not need cleaning' unless he has done a flow test on them in which case they may as well have run cleaning solution through them while in the flow machine.

Not enough detail from your post i'm afraid.

I assume you have Googled 'Black Death Mercedes Diesel'
 
@Petrol Pete sorry for my previous post to not to clearly stated the garage's process.
Based on their speech, they confirmed they cleaned the surface of injector slot, re-seal and replace the copper washer.
But they confirmed that they haven't cleaned or tested the injectors by flow-test, they just did a visual test of the leaking injector.

As you've mentioned, they have just taken the old ones out, cleaned everything then put them back in by replacing the copper washer and injector bolt.
I couldn't find any other garage or injector service around Worcester. I don't want to take my car to amateur garages to get my injectors re-seated.

btw, I have googled and watched too many videos on youtube, I know what's the right process in order but I don't have flow-test or injector cleaning kit and I snapped one of the injector bolts while trying to re-seat and tighten by myself :(
It wasn't my fault as I was tightening lower than 15Nm but the injector bolts were replica of ELRing...
 
Last edited:
Often injector nozzle holder side surface is forgotten to check/refine, if leak has damaged that side.

Problem is ALL MB CDI engines, even after decades, they have not changed attachment construction. One M6 bolt (assymetric) per injector is no good.
 
@mersum1es I'm with you.
I believe, this is the biggest design issue for MB CDI engines. Asymmetric fixing with one M6 bolt.
Actually, 2 of my injector bolts have been replaced with M8 as I have snapped one 🤬

Unfortunately, we have no chance to see what are they doing during this process. What details are they checking or are they cleaning/refining the nozzle holder surface? And once the leak starts, it's not easy to see where does that leak come from as surrounding of injector becomes black and gunky.
 
But I believe, always new copper washer should be used after cleaning the injectors and injector hole. Did I misunderstand? What’s wrong with it?
 
If injector nozzle cap is damage free ,and the surface of cylinder in head is clean( I prefer to polish it using sandpaper on lapping stick) ( some use a cutting tool ) and new bolt used and torqued properly there will be no leak for a long while
 
OP . You told us you have watched many YouTube videos about Black Death in MB . so you must of seen this one from Alex (ex MB master technician) at Legitstreetcars.

I have added it here just in case you missed it.


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OP . You told us you have watched many YouTube videos about Black Death in MB . so you must of seen this one from Alex (ex MB master technician) at Legitstreetcars.

I have added it here just in case you missed it.


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For more detailed information, see our cookies page.
Thanks @Petrol Pete,
I watched it, too :)
 
If injector nozzle cap is damage free ,and the surface of cylinder in head is clean( I prefer to polish it using sandpaper on lapping stick) ( some use a cutting tool ) and new bolt used and torqued properly there will be no leak for a long while
I believe they’re doing these steps but haven’t seen of course:)
Maybe it’s better to go to the same garage for the last time to re-seat the 3rd injector
 
I believe they’re doing these steps but haven’t seen of course:)
Maybe it’s better to go to the same garage for the last time to re-seat the 3rd injector
Let the garage take the injector out , you inspect it for wear to the the nozzle cap , If wear is evident take it to your local diesel specialist and ask them to replace it.

My local diesel specialist did clean shot blast my injector , fitted a new nozzle cap all in for 15 quid , New nozzle cap looks much smoother and with more mating surface than the old one they removed
 
Thanks mate, I’ll go back to my garage for the last time. If they won’t be able to re-seat my 3rd injector properly, I’ll go to injector specialist next time. I just found an injector specialist 100miles away from me :) a bit far away from me but their reputation is quite well.
 
Hi again,
I can clearly see that fuel is bubbling around the injector :( it’s getting worse.
And MB Worcester asked me to pay £167 for diagnostics in advance to fix any issue.
Does anyone have any suggestions?IMG_0584.jpeg
 

Get a one from your diesel garage, by injector part number....


cracked one:
Thanks very much @mersum1es
It’s very clear now. I guess you’re right, because smoke is not coming out, only clean diesel fuel is coming out and bubbling.
Tomorrow morning I’ll drop my car to the garage and see what they’ll say against your thesis :)

Thanks again
 

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