Need Help with OM606 NA, smoking like a train - PeachParts Mercedes-Benz Forum

Onetoomany · #1 12-09-2014, 04:46 PM

Hey there everyone,

I'm posting on this forum after being a lurker for awhile, and need some help from the powers that be.

My car is a 1995 E300D, OM606 motor, non-turbo. 240K miles, and I'm in the middle of getting it back to life after the IP took a nose-dive.

I have replaced EVERYTHING in the fuel system, from the tank strainer up to the injectors, which I had digitally balanced, rebuilt and pop-tested with new Bosio nozzles by KermaTDI.

I just got done today with putting the IP back in, and reassembling the motor. I had to wait on the mercedes locking tool for the IP, its critical, and can't be gotten around.... (ask me how I know...)

Anyway, the motor fires up, but I have severe "chuffing" out of the tail pipe, and I think I can hear a slight nailing from one cylinder.

I'll attach video clips of my exhaust and engine, which has the ability to smoke out my garage in roughly 8 seconds right now, but is a LOT better than the last time not using the IP locking tool.

The issue seems to be an overfueling problem, which, starting tomorrow, I'm going to try and isolate to a given cylinder. The question, and the reason for this post, is what would make one cylinder overfuel? Timing?

The replacement IP is a mercedes re-man unit from the benz store in atlanta, and was supposedly bench-tested and checked out.

Any and all help is appreciated guys, if you want the full saga of this project, its over on another forum, and can be found here: 1995 E300d sudden power drop/no-start - Mercedes-Benz Forum

Youtube clips of motor and exhaust today after reassembly are here:

Motor - http://youtu.be/NTJ9L4nvqaw

Exhaust - http://youtu.be/Rk2dwTGCPkY

Thanks in advance for your help!!

- OTM

vstech · #2 12-09-2014, 04:50 PM

Hole in piston?

Pull oil cap... does it puff also?

GregMN · #3 12-09-2014, 04:58 PM

How did it run before you did the work on it ?

Onetoomany · #4 12-09-2014, 05:05 PM

Ran fine, apart from abrupt stall when IP gave out - bearings and metal shards all over when I pulled back plate...about 3 days prior to IP death I noticed a little white smoke in the mornings, but no coolant smell, and started right up.

No smoke from oil cap.

motor has plenty of power now that IP is replaced and catalyst replaced.

GregMN · #5 12-09-2014, 05:26 PM

If you determine that it is a single cylinder:

A single cylinder problem has to be isolated to that cylinder.

The injector. Try moving it and see if the problem moves with it.

The IP piston for that cylinder.

The cylinder's piston rings, piston, cylinder wall, valves. If everything was fine before, it would not likely be those.

Onetoomany · #6 12-09-2014, 10:15 PM

How is the IP piston for each cylinder serviced? Is that the piston under the delivery valve body? Is that somehow adjustable, and thus, responsible for the overfueling of that cylinder?

If I get it isolated I'll swap injectors - good idea, thank you! Kerma did a really nice job on them, but I'm sure there has been ample time for some nasty bits to slip in there during all this work.

dieselbenz1 · #7 12-09-2014, 10:24 PM

Is the engine warm when you recorded the tail pipe video?

Onetoomany · #8 12-09-2014, 10:44 PM

yes at 85~ degrees C after a short highway drive. I took it out to run it and see if that would make any difference.

Lucas · #9 12-19-2014, 12:03 AM

Quote:

Originally Posted by Onetoomany

How is the IP piston for each cylinder serviced? Is that the piston under the delivery valve body? Is that somehow adjustable, and thus, responsible for the overfueling of that cylinder?

.

Yes. That video sounds exactly like its a tooth or two off. An old school trick is to clock the barrels a tooth up to increase fuel. But better results when you do all 4 (or 6 in your case?) and have a turbo you can tune up.

What's up with the new IP coming? Warranty?

And where are you? If you are near central coast California, there's a really good IP shop here, and a mercedes guy in there that is well known.

barry12345 · #10 12-19-2014, 12:44 AM

Quote:

Originally Posted by Lucas

Yes. That video sounds exactly like its a tooth or two off. An old school trick is to clock the barrels a tooth up to increase fuel. But better results when you do all 4 (or 6 in your case?) and have a turbo you can tune up.

What's up with the new IP coming? Warranty?

And where are you? If you are near central coast California, there's a really good IP shop here, and a mercedes guy in there that is well known.

When and if you exhaust all possibilities. No pun intended. Pull the number one injector and run the engine. If you get an oil mist out or the injector hole or the injector appears to be oil soaked or not normal looking perhaps.

You may have a failed head gasket from the pressure hole to the head to the number one cylinder. I doubt that if with number one on line your revs can pick up by a thousand unless loosening any other injector drops them by a thousand rpms as well. Maybe it will. I doubt an injection pump can provide enough fuel to cause clouds of smoke from one cylinder.

The smoke would be black rather than blue I suspect as well with a bad pump. If I ran out of places to examine I would go there. Just thought I would throw this into the mix. Coincidences do happen. I am in no way trying to displace previous thoughts.

Onetoomany · #11 12-19-2014, 09:35 AM

Guys,

Much appreciated. The IP that is currently in the car is a used unit from the Benz Store in atlanta. The one on the way is another used unit from the same place.

I'm in Scottsdale, AZ now, but lived in atlanta for the last 7 years.

The OM606 doesn't require valve adjustments like the earlier W123 chassis diesels. It's pretty bare bones basic, no turbo, etc.

Re: idle speed - with all 6 injectors connected and running, it lopes along at about 650, with smoke from #1 when trans is in drive. When in neutral, it goes up to about 1K.

When #1 is taken offline, it stumbles a bit (clearly) and then goes back to 650-700ish in park, and the smoke is gone.

I had the current IP installed wrong before I bought the locking tool, it was a tooth or two off, and man, that thing smoked like a coal burner. Timing is back to where it should be, 14.5deg ATDC now that locking tool is here.

I'd be interested to get head rebuilt if that is what its going to take, I know this motor has had the head upgraded in the past, the OM606 has some known head gasket issues from time to time.

Is there some type of definitive test that would allow me to determine if the head needs to be pulled? Can anyone link to the procedure? I've done heads before, but never on the OM606.

And yes, if you have a diesel injection shop in CA, I'd love their name/number - I want to keep this thing running, not go buy another.

Thanks!

funola · #12 12-19-2014, 12:14 PM

Onetoomany, was the car running normal before the IP grenaded? What was the cause of IP failure?

Rscurtis thinks #1 is starved of air. I am wondering if he is hinting at something like a sock in the intake? Don't laugh, I remember a thread where after a total rebuild (VW diesel) with a rebuilt IP, guy had a problem with one cylinder and after trying many things plus $800 in parts later, it ended up being a forgotten sock. This guy works in a machine shop too so these stupid things can happen to the best.

How big a job is it to pull the intake and have a look?

dieselbenz1 · #13 12-09-2014, 10:59 PM

Do you know what the pop pressures for the injectors were set at?

Onetoomany · #14 12-09-2014, 11:41 PM

I do not have pop pressure figures. I do know that Kerma sent them to their injector shop, and they were all balanced and digitally calibrated within 0.5psi of each other.

moon161 · #15 12-10-2014, 08:26 AM

Loosen fuel lines to kill the injectors one at a time. If you can turn the problem off this way, the problem is an injector, or the fuel delivery to it.