Getting ready to make some offers on 05/06 CDIs...

My Only MB diesel was 84 300sd-- Great car-- Let it go- w/275k-- leaking TOO much oil (wish I was more patient)

Will this OM648 leak as much (w/ 220k + miles)--as the 617? Or did MB get better/designs/gaskets/etc.

some- always throw out-- "All diesels leak oil" - don't know if I buy that

Just want to know what I am about to get into

Even my 606 was leak free with 250 k miles...the 642s are too once you change the oil cooler seals.

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The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech

My 05 E320 CDI at 200k mi with Om648 was leaking around the valve cover gasket and was dripping on to the air filter box and exhaust heat shield (engine tilted more towards passenger side) but elsewhere it look pretty dry. I'd be more worried about the injector seal failure (ie black death) than oil leaks.

I bought my E320 CDI for $1900 with a injector seal failure that happened for some time (probally 1-2 yrs) and was daily with that problem, owner never addressed it. I just got done replacing the seals and cleaning, it was quite a job but straightforward (i had worst OM642 oil cooler seal!) and relatively low cost, the kit cost $30 minus the other tools and unforeseen consequences was costly ($200 in tools & custom tools, supplies, broken T return lines $230 OTD)

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Current Garage
2008 Mercedes GL320 CDI 188k mi Repair/Work in progress
1994 S350 160k mi Garage Queen & prepping for repairs
2005 E320 CDI 203k mi Healthy & Daily Driver
1994 S350 357k mi Retried as parts car
1984 300TD 214k mi Blown OM617 Poss OM603 Swap??

Sold
1987 300SDL 200K+
1994 S320 181K mi
2008 E320 Bluetec 127k mi
1999 S420 130K mi
1980 240D 360k mi
15+ Others that has come, stay and gone

GONE, BUT NOT FORGOTTEN
1995 E320 SE 220k mi
1984 300SD 350k mi

The benz diesels are not leakers any more than any other vehicle with miles on it.

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[SIGPIC] Diesel loving autocrossing grandpa Architect. 08 Dodge 3/4 ton with Cummins & six speed; I have had about 35 benzes. I have a 39 Studebaker Coupe Express pickup in which I have had installed a 617 turbo and a five speed manual.[SIGPIC]

..I also have a 427 Cobra replica with an aluminum chassis.

Any diesel with higher miles will leak. Diesels naturally have higher crankcase pressures. So when they get some miles on them, they’ll leak. And have fun stopping them. When you replace one seal the next closest leaks. I’ve tried on diesels with 400k plus.

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Only diesels in this driveway.
2005 E320 CDI 243k Black/Black
2008 Chevy 3500HD Duramax 340k
2004 Chevy 2500HD Duramax 220k

My advice on oil leaks echos Bob Newhart suggestion. "STOP IT!" (https://www.youtube.com/watch?v=4BjKS1-vjPs)


I've had several Mercedes diesels over the years along with 2 Cummins recently added. Everyone says all diesels leak, "cummins sweat horsepower" and all kinds of nonsense.

I don't own a vehicle with less than 200k, I've had some nearing 400k, and none would leak more than a drop parked overnight or something was getting fixed.

My driveway has been littered with oil stains at times, somewhat from my friends who aren't as OCD about replacing rubber parts, and some from the process of getting my cars and trucks to where they are today.

Anything can be a leaky nightmare, anything can be a flawless shining example of engineering.
Its all in how you care for it.

My worst experience with any car is the w124 I owned, Somewhere there is a thread about the "cursed" car. It had been neglected and bodged together for many years and I spent way too much on it before finally nearly giving it away so I'd stop spending money trying to fix it.

Most of my vehicles are "rescues" in one way or another, but sometimes they're too far gone to be worth saving.

Turbo drain seals, valve cover seals, air cleaner U-Tube gaskets, oil separator modifications/repairs, and the driveway will be clean right up until my wife parks the backhoe on it again lol

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1982 300D (w123, "Grey Car")
1982 300D (w123, "Blue Car")
2001 Ford F150 "Clifford" (The Big Red Truck)
1997 Dodge Ram 2500 12V Cummins
1996 Dodge Ram 2500 12V Cummins
Previous Vehicles:
1995 E300D, 1980 300SD, 1992 Buick Century, 2005 Saturn Ion

My 617 leaked. Then I bought a gasket set (Elring I think), took it down to the long block and sealed everything. It hasn't leaked since.

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85SD 240K & stopped counting painted, putting bac together. 84SD 180,000. sold to a neighbor and member here but I forget his handle. The 84 is much improved from when I had it. 85TD beginning to repair to DD status. Lots of stuff to do.

Well I found another leak point in the 642.

OM642 oil filter gasket

Much easier repair than the oil cooler seals.

__________________
The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech