Well Brian, you are correct about the oil chains in these things. Take a look at the photo of the broken link on my oil pump chain.

Sometimes you just get lucky, I had just finished driving home from MN to CO (950 miles) when I stopped at my highway off-ramp (2 miles from home) and saw my oil pressure gauge drop to "0." I shut it off and had it towed home (it was stopped in a bad spot). When it cooled, the oil pressure was reading lower than normal by about 1 bar, but I felt OK to drive it to my indy. He diagnosed a bad gauge (the gauge was bad) and replaced it. The pressure was reading normal with the new gauge.

I had also asked him to take care of a few typical oil leaks (return tube, manifold gasket, etc.) while he had the car. He was concerned with the RTV that I had put on the air cleaner return tube, and wanted to drop the pan and make sure it hadn't gotten to the intake screen. When he dropped the pan, he noticed pieces of a chin link in the pan. I should have a new chain/pump/etc. installed by friday. We never would have found this if it wasn't for the silly gauge problem, I don't know how long the chain would have held together, but I'm glad I didn't find out.

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yeah, the oil pump chain does not last as long as the cam chain. probably because it is so much shorter it gets three or four revolutions to each revolution of the cam chain.

you might think mb would recognize this with a different design of the chain.

i bet a lot of folks don't even realize there is a chain drive on the turbo motors.

i didn't know til my favorite machinist asked for one when we rebuilt my first mb diesel, the one in my 82 300td.

tom w

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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.

How does one replace the oil pump chain?

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Bob
'82 300D Petrol B-G Metallic

Not sure, I just bring it to the shop and give them a large check when they finish.

You got real lucky! Good catch!

If you have a 617 with over 300k on it you really should change the oil pump chain.

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1999 SL500
1969 280SE
2023 Ram 1500
2007 Tiara 3200

I wonder what made MB switch from the shaft drive to chain on the OM617.

I have an oil pump chain that looks like that too. I think it's been that way for quite some time but it eventually will eat away at the plastic tensioner (as was the case in mine). The FSM makes it sound like major effort to change it (and that doesn't include just getting there).

I didn't have a chain nor chain link tool so had to seal her back up and take my chances. This chain as I understand from other posts is under a lot less load than the timing chain so fingers crossed is less likely for catastrophic failure even apparently then the tensioner is gone (as demonstrated before I fixed my tensioner).

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1982 300TD 210K miles ("The Replacement" aka "The Anvil") - SOLD
1979 300SD 245K miles (never ending project)
2007 Pinarello F3:13
1995 Ducati 916 (SOLD, sniff)
1999 Ducati 900SSie (SOLD)

My indy wouldn't even start it to drive it from the parking lot into the shop after he found out what was going on.

Hmm... I was always under the impression that the oil pump chain basically lasted indefinitely since it is basically always part-submerged in oil......

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-Matt

EPA Section 609 Certified MVAC Technician
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Oil Burner Kartel Member #10

Ahh the smell of Diesel Fuel, it's like coffee in the morning!

My Car:

1982 300SD Turbo Diesel (231,500 miles!) RIP

1984 300SD Turbo Diesel Custom (235,500 mi on driveline.) - On Road!!

www.icsrepair.com

I certainly don't recommend the practice..this car had to be moved off of a friends property under its own power...but I also think catastrophic failure is further off than the problem would suggest.

there's still a fair amount of material holding that chain together plus low tension. Tensioner plastic is what takes the most damage. Even without broken links the tensioner will have massive (relatively speaking) grooves worn into it after 200K+ miles so should be replaced along with chain as mentioned above towards the 300K mark. Both can be inspected by pulling the lower pan (which probably needs a new gasket around inspection time anyway).

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1982 300TD 210K miles ("The Replacement" aka "The Anvil") - SOLD
1979 300SD 245K miles (never ending project)
2007 Pinarello F3:13
1995 Ducati 916 (SOLD, sniff)
1999 Ducati 900SSie (SOLD)

Ok, so is this specific only to the turbo models or true to all things 617? I was of the impression they were gear driven like the 616 until now, I will be soon (hopefully) pulling my engine for it's transplant and if this is something I need to look over while it's out, I want to make sure it gets done. This will be the engine's 3rd known transplant, and I have no past knowledge of where the engine origionally came from.

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Chris
64 190D R.I.P.
80 240D W/617 engine -for sale
82 240D -for sale

Not sure, I thought all 617s had a chain, but I could be wrong. Someone must know for sure?

That sounds like a good idea, I'm also having them replace the pump while they are at it (just because).

Yikes!

Don't forget to post how many hours the repair takes.

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1979 240D- 316K miles - VGT Turbo, Intercooler, Stick Shift, Many Other Mods - Daily Driver

1982 300SD - 232K miles - Wife's Daily Driver

1986 560SL - Wife's red speed machine

It will be interesting to see what it takes to replace the chain/pump. I already had them chasing down a bunch of little oil leaks (return tubes, manifold gasket, etc.), with an estimate of about 8 hours, or so. They also replaced the oil pressure gauge (which was reading low and leaking), before they dropped the pan. The whole mess should cost me at least a couple $1000, maybe a tad more. As long as they get it all back together by friday, I need to drive to MN again on sunday and I would like to take that car.