Rolling Coal When Putting the Pedal Half Way
 

Is this normal on an OM606? Both of my cars do it and they're on their original injectors. Both have been diesel purged as well and I'm in no hurry to re-nozzle them, they have the same fuel economy on the highway and around town and no nailing. When I put it half way to the floor to pull out or merge, a friend of mine made mention of how it blows out some black smoke.

some smoke is going to happen on an IDI diesel, there's just no way around it. The quantity is what's important. Is it just a haze of black smoke, or are you belching out a portable hazmat site like the Cummins boys do? If the latter, you may need to look into it further.

The turbos might not be spooling quickly enough to keep us with fuel enrichment. In the '92 you can swap the vacuum wastegate actuator for a pressure actuator and/or adjust the ALDA. I don't think it's that easy in an electronically controlled 606. Is there more than a hair's width of radial play and any axial play in the turbos?

Sixto
83 300SD
98 E320 wagon

I don't think that's normal. Didn't see it on the 99 I had and didn't see it on the 98 until I got it chipped tuned....now there's mild black haze on hard acceleration.

Are you seeing it at night? Its always very visible in the rear view at night with a car behind.

Before you aftempt any fix, replace all the rubber connectors and T's. Everything works on vacuum, including turbo control, transmission, HVAC and emissions. Many obstinate problems are caused by degraded vacuum hoses.

My silver E300 has a rebuilt turbo at 290k, and I checked my e300 and the shaft has next to no play...

Nothin' like the cummins boys. It's nothing more than a haze. I figure if it is something serious I'd see a drop in fuel economy.

Yes, this is at night mostly.

On my Dodge/Cummins (mine is pre-Ram) with the tuner set on "Towing" it blows some smoke if I take off at full rack. In other words, it blows smoke a lot! But I get 24MPG on the highway and 18 when towing the race truck and trailer over the mountains so I don't think it's wasting too much fuel. Even around town I get 14-16 MPG depending on the driving cycle for that tank full (how much highway vs. city use).

Dan

That is normal to be able to see it at night.

Dan, what year is your Cummins?

BOT - My 82 300D barely smokes at all compared to my Cummins trucks or TDI's. I was revving it at 1/2 to 3/4 throttle in the back of the barn 20' from the open door and it smelled in there but wasn't all that hazy at all. Surprised me.

My 83 SD is the same way - no visible smoke during the day but a haze in the mirror with hard acceleration at night. It's not rolling coal since it's not black. In my case the turbo is tired.

83 300SD
98 E320 wagon

It's actually an early '02. I have to order parts for it as an '01 as there was a mid-year change and mine was before that change. Ordering '01 parts gets me the right thing every time. I think some of the parts guys around here think I have 2 of them as I'll order parts for an '01 but if they need the VIN it is, of course, for an '02.

Dan

Just wondered, I don't know anything about those from that era.

I do know that would be a 24 valve since they started in 98.5 I believe, I don't know what the model split at 01.5 entailed.

That's pretty good mpg, I had a 92 D250 5 speed that got 25 or better on the highway unladen (Monty Python reference there).

I have owned 6 or 7, all 12 valve first gen trucks (89-93). Down to one now, a 92 D350 dually 5 speed manual standard cab. Most reliable vehicles I've ever owned over 40 years of driving and 100+ cars, which seems odd for an early 90's Chrysler product. My 84 diesel Rabbit was close second. Must be that engine wiring harness with 3 or 4 plugs.

Dodge seems to be almost VW-like in their ability to split model years, haha. I have a 2005.5 Jetta gas car and I have to order 2006 parts to get the right stuff. I believe the Cummins 12 valve intercooler started in 91.5 as did the new front grille design to feed the intercooler. Order for a 91 and you'll get the 89 era non intercooled engine and front end design.

I'm new to Benzes so I don't know if they are the same on these weird model year splits, or not. I've learned from VW's to just go with the VIN.

Unlike what I've seen from my Benz, my Cummins trucks WILL obscure entire sections of highway in smoke if I have to floor it to merge onto the highway, and that is in stock tune.

Joe

There aren't many mid-year model splits with these MBs. It's more common that parts are different by chassis or engine serial number range. Most MB parts websites indicate such in the part description. A big difference is federal vs California emissions systems in &4-86 MY Diesels.

Sixto
83 300SD
98 E320 wagon

So far my MB has been pretty consistent with it's model year ('85) but I understand they they threw a curve ball if you have an OM617 in a station wagon. They used some sort of self-leveling suspension and the entire cylinder head is different - something about mounts for the suspension pump or something. I haven't personally run into this so I have zero experience but just a heads-up.

I really prefer the 24 valve engine. They have a couple of ideocyncracies (sp?) but all in all they make great power on less fuel. I've been deep inside these engines as part of my work experiences back in my working years (I reblocked one as well as less invasive work) so I know how stoutly they're built. If you end up with one I'll tell you what they need to live long and prosper.

Dan