'05 CDI injector "Black Death" adventure - Page 2 - PeachParts Mercedes-Benz Forum

ROLLGUY · #16 02-12-2017, 05:44 PM

Quote:

Originally Posted by RunningTooHot

Thanks for documenting the deep-dive down the rabbit hole of "black death". (Perhaps this form of 'death' isn't to be feared as much as previously thought?) Job well done, and much appreciated!

I've been chomping on the bit about getting a CDI for the last few years. "Black Death" being one of my primary concerns. This helps allay those concerns and may just push me to further rationalize my "need" for another car. (Which I need like I need another hole in my head.)

One question:
Did you closely inspect the conical seal face for any evidence of erosion from the escaping gasses? IIRC, re-facing the seats is sometimes required. IF you had run up against that, what was going to be your plan of attack?

Thanks RollGuy!

It is a big job for the dealer (= costly), and that is probably where most of these were repaired when it was evident. I inspected the seat, and it is flat, not conical. The worst one looked exactly like the best one (seat in the head). Number one injector still had a nice coat of the ceramic paste on it, and no sign of seal leakage whatsoever. The worst one (#4), had carbon around the entire circumference of the copper seal, so I suspect the leak was across the entire surface, not just in one spot. Therefore, no erosion of the head has occurred.

funola · #17 02-12-2017, 08:50 PM

Quote:

Originally Posted by ROLLGUY

Yes there is supposed to be, but it was not there on this car.

No foam cover now does not mean it never had one. Are you saying the foam cover has nothing to do with the black death in your car because it does not have one?

spock505 · #18 02-13-2017, 01:51 AM

Maybe that was it, the bits in the bucket lol

ROLLGUY · #19 02-13-2017, 10:11 AM

Quote:

Originally Posted by funola

No foam cover now does not mean it never had one. Are you saying the foam cover has nothing to do with the black death in your car because it does not have one?

I saw remnants of the foam, and I suspect the dealer I bought the car from left out/threw away the foam or what was left of it when I had them take a photo.

ROLLGUY · #20 02-13-2017, 11:04 AM

I left the bolt torquing till last for two reasons. I have not found a definitive torque spec, and I didn't have the proper torque wrench until yesterday. Although I am sure the initial torque is 7 nm, I am not sure if it is then one 90deg. turn or two. I have read a few threads on the subject, and some say that MB spec is two 90deg. turns after the 7, and most others say only one. I think I will be safe and only do the one, but would like some input on this. Also, I had to buy an inch pounds torque wrench, as my other one does not go down to 7 nm. Does anyone know what 7 nm is in inch pounds? My wrench will go 20-200 inch pounds, so I figure it will be more accurate than a foot pounds torque wrench will be....... Rich

Mike D · #21 02-13-2017, 02:07 PM

1 newton meter equals 8.85 inch pounds. 7 nm = apx. 62 in-lbs. or just a hair over 5 ft-lbs.

BillGrissom · #22 02-13-2017, 02:26 PM

Thanks for posting. Those engine covers look purty, but can hide many sins, so smart you had them remove it for photos. It looks like a fairly straight-forward fix, so surprised the dealer shied away. They must have seen it before. Perhaps they were afraid that the head might be damaged.

I don't know CDI's, and neat you are digging in. Any idea what pressure that "common-rail" fuel supply manifold runs at? I have heard such new diesels typically run ~20,000 psig. If true, is isn't surprising that leaks are common. I understand that Fiat developed the technology (and also gas direct-injection) and M-B and others license it. Gave Fiat the cash to buy Chrysler.

ROLLGUY · #23 02-13-2017, 02:33 PM

Quote:

Originally Posted by Mike D

1 newton meter equals 8.85 inch pounds. 7 nm = apx. 62 in-lbs. or just a hair over 5 ft-lbs.

Thanks!

funola · #24 02-13-2017, 02:50 PM

Imagine if Mercedes used a foam that is resistant to diesel fuel and heat, there would not the plaque of CDI Black Death.

MB_FanAddict · #25 02-13-2017, 03:19 PM

Quote:

Originally Posted by ROLLGUY

I left the bolt torquing till last for two reasons. I have not found a definitive torque spec, and I didn't have the proper torque wrench until yesterday. Although I am sure the initial torque is 7 nm, I am not sure if it is then one 90deg. turn or two. I have read a few threads on the subject, and some say that MB spec is two 90deg. turns after the 7, and most others say only one. I think I will be safe and only do the one, but would like some input on this. Also, I had to buy an inch pounds torque wrench, as my other one does not go down to 7 nm. Does anyone know what 7 nm is in inch pounds? My wrench will go 20-200 inch pounds, so I figure it will be more accurate than a foot pounds torque wrench will be....... Rich

The TDM has a typo apparently (it lists stage two twice!), so I double checked the current service info online.
There are in fact two 90° turns for the injector clamp bolt. Tighten to 7Nm (stage 1), 90° (stage 2) & 90° again (stage 3).

The torque spec for the high pressure injector line nut is 23Nm (single stage).

ROLLGUY · #26 02-13-2017, 04:05 PM

Quote:

Originally Posted by MB_FanAddict

The TDM has a typo apparently (it lists stage two twice!), so I double checked the current service info online.
There are in fact two 90° turns for the injector clamp bolt. Tighten to 7Nm (stage 1), 90° (stage 2) & 90° again (stage 3).

The torque spec for the high pressure injector line nut is 23Nm (single stage).

I was afraid to tighten them any more than 90* after the 62 inch pounds. In reading threads on other forums, the consensus was only the first 90. There was even a post where the guy went the second 90, and stripped the hole in the head. I will check the injectors at least as often as each oil change.

ROLLGUY · #27 02-13-2017, 04:16 PM

I got the parts today that finish the job, and got the car running. Everything looks great, except for a fault code of "open circuit glow plug #2". I found that it is broken off in the head:

ROLLGUY · #28 02-13-2017, 04:19 PM

I made a fixture to hold a dummy plug. It seems to work just fine, and now I can get the car smogged.

chronometers · #29 02-14-2017, 12:28 AM

Quote:

Originally Posted by ROLLGUY

I got the parts today that finish the job, and got the car running. Everything looks great, except for a fault code of "open circuit glow plug #2". I found that it is broken off in the head:

I guess with the black death, you and the dealer could not see the broken glow plug before you bought the car?

ROLLGUY · #30 02-14-2017, 12:35 AM

Quote:

Originally Posted by chronometers

I guess with the black death, you and the dealer could not see the broken glow plug before you bought the car?

I bought the car without looking at it with my own eyes. I only saw photos. I did not even drive it. If I did, I might have known about other problems (however minor they might be). The car was headed for the auction, so no work was done on it other than a detail job. If I did not ask them to look for black death, the car might have been sold at a much higher price. Seeing the black death brought the price way down. A broken glow plug was not even on their radar (or mine).