What's the best place to buy OE pistons (OM617)?

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The best advise is - DON'T! The OM617 uses wet sleeves and they are replaceable. Generally the pistons are OK and renewing the bores means that you can reuse the pistons in essentially a new bore. You'll want a fresh ring set but again they're not too expensive.

The reason to do this? Sleeves are fairly cheap and pistons are VERY pricey. If the pistons have failed in some way it might be cheaper to buy an engine from PnP and rebuild using those pistons. Like I said, the pistons generally last forever. If you REALLY need new slugs, this is NOT a place to cut corners. Pelican Parts likely has as good a price as any for quality parts.

Dan

X2. You get can OEM sleeves x5 with shipping for under $120. If you are taking the engine down to that degree, then getting them pressed out, new ones pressed in, and the engine deck milled is a small price. X2 on the pistons as well. Grab a rebuildable engine at P-A-P or grab one for parts. A lot cheaper and you're getting a known commodity.

New turbo pistons list for ~$550 EACH. There was a set of 5 new ones for ~$850 on ebay a year or so ago. I passed and ended up buying a used motor off craigslist for $300 that proved excellent (recent rebuild?) and even came w/ a starter. Also moving slowly on rebuilding my engine. Bought a set of used pistons for $100 from a member here, since several of mine were damaged. I got Meyle cylinder liners cheap ($12 ea). See my post on how I removed the old ones - easy with a screwdriver and hammer, and a post how I installed the new liners. Then you must take the block to a machine shop, my next step. BTW, mark your oil squirters before you remove them. I didn't and then read that they differ.

Wet Liners/Sleeves are exposed to the Coolant (hence the term Wet) and are thick and normally have grooves on the OD for Seals.

Dry Liners/Sleeves go into a Bore in the block and the other sided of the Block Bore is what is exposed to the Coolant. The Liner/Sleeve does not have direct contact with the Engine Coolant

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84 300D, 82 Volvo 244Gl Diesel

NAPA sells KS Pistons for the turbo Diesel 300D Turbo they were $200 for the set.

DeliveryValve related to Me that spoke with someone from MetricMotors and they do not pull/remove the Old Liners but re-bore the Old Liners to fit Over sized Pistons. In that way they avoid having to re-surface the top of the Block and do not have to spend time on installing and removing the Liners/Sleeves.

If you install new Liners you spend time removing them, you have to install them correctly and then have the Liners bored out to fit the Pistons and after that re-surface the top of the Block so the top of the Liners are flush with the block.

the only way to tell if Pistons can be reused is to remove them and measure them and the Ring Lands and Grooves.
This is what I have seen on other Diesel Engine; often the Piston Skirts/OD is good but the upper Compression Ring Grooves are worn and sometimes the Scraper Ring.

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84 300D, 82 Volvo 244Gl Diesel

When I had my non turbo OM617 troubles it worked out cheaper to buy a set of new Kolbenschmidt pistons than it was to have the (dry) liners replaced. I was told after pushing out they need to be bored to size and honed which was expensive in labour costs.

Holland has expensive labour rates. In my case an oversized bore + hone + new pistons worked out to be the cheapest.

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1992 W201 190E 1.8 171,000 km - Daily driver
1981 W123 300D ~ 100,000 miles / 160,000 km - project car stripped to the bone
1965 Land Rover Series 2a Station Wagon CIS recovery therapy!
1961 Volvo PV544 Bare metal rat rod-ish thing

I'm here to chat about cars and to help others - I'm not here "to always be right" like an internet warrior



Don't leave that there - I'll take it to bits!

I just saw this post. You appear to have lucked out on new pistons. On NAPA's website I now see:

Part Number: ATM RY6187000
Product Line: Altrom
IMPORTANT INFO: Standard
$1779.

Standard size, so one would also need new cylinder liners ($43 ea NAPA).

Pretty much all their parts for my 84 & 85 300D's are beyond my price points (I would go URO first). It looks like an engine rebuild w/ NAPA parts today would run ~$4000, plus machine shop costs. I would consider installing a U.S. small block before that. Indeed, I have a Chrysler 273 that would look nice in there, except its oil pan drops down in the rear. Anyway, I have enough parts to rebuild my 1985 diesel engine when I get time.

Not at all. It is just a typo. I could not remember the exact cost so I was trying to type $2000 (For the Turbo Diesel).

Besides being a poor speller I have Arthritis in My Fingers and when I type I think I did OK but sometimes something does not get typed or the a lette gets put in in the wrong place due to a stiff Finger being slower that the other.

The I have other problems I cannot explain. Everything comes out as everthing and I want to spell Glow Plug either comes out as Gloe Plug or Glow Plut.

If I take the time to spell check that helps some but the $200 instead of $2000 mistake would not show up on the spell check.

For non-turbo Pistons there was a Seller on eBay that was selling Made In Taiwan Pistons.
One of our Member or a Benzworld Member in the UK said he orderd those and would give feedback on them.
I either missed the Feedback or he never reported back on them.

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84 300D, 82 Volvo 244Gl Diesel

I haven't personally replaced Benz liners but I was led to believe that they were wet like big US Diesel liners. With the big Diesel liners you simply pull the old ones and install the new ones with no further machining. I had the impression that this was the case with the OM617. Evidently that is not the case - I sit corrected (I'm sitting at the computer so I don't "stand" corrected!).

The way this works is that there is a step machined at the top of the bore and the liner has a lip that sits into that step. At the bottom of the bore there's an O-ring that seals the liner to the block. When you assemble it everything lines up and you're done. The head holds the liner from climbing up and the step stops it from sliding down. Some of these rebuild kits come with pistons and rings and some do not. There are even kits with gaskets and a rebuilt head so at the end you have a whole fresh engine. Not cheap but nothing is for the big fellas.

Dan

It depends on the Engine Maker. Back previous to the 1986; the last time I did any Diesel Engine rebuilding Detroit Diesels had Dry Liners.

On the Detroit Diesels you had to remove the the Dry Liners and measure the Block Bore. If that was out of round then that needed to be bored or honed for a larger OD Dry Liner. However, that does not happen often.

Cummins Engines had Wet Liners. With the Wet liners often the Sealing area of the bore in the block can get eaten up/corroded. However, if you Coolant is kept to the proper strength that does not happen for many may years.

If a Piston gets fried or a Valve drops into a Cylinder Truck owners only replace the minimum needed to get the Vehicle back on the Road to make Money. That means only the effected Cylider and related parts are worked on.

From what I have read on Mercedes the #1 Cylinder is bored slightly larger than the rest.

On My Volvo Diesel there is no Liners. I had to get oversized Pistons.

Old Renault Cars from the 1960s had Wet Liners. I guy I worked with had one.

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84 300D, 82 Volvo 244Gl Diesel

I was being generic there just as a frame of reference. Cummins ISBs for example just use a cast cylinder with no liner at all and have to be bored oversize or sleeved (the process for installing a generic dry liner - been done for decades). Most Cats use a wet liner. So it depends. I was just trying to give the reader a general idea of what I had been led to believe on the 617 which turns out not to be true.

Dan

Just to clarify, my OM617.952 (1985 CA 300D) has "dry liners", as I expect all similar M-B diesels do. I replaced my liners. Lookup my post w/ photos. 1986+ engines have an aluminum block, so may be slightly different, though heating the block should help more with them.

Driving a cheap screwdriver between the liner and block from the bottom quickly splits a slot in the cast iron so you can peel it out (1 min job). As I recall, there is a lip at the bottom of the block that the new liner seats on and a recess groove at the top. To get the new ones in, I heated the block over a propane stove and chilled the liners in the freezer. Wasn't quite enough as I still had to use a sledgehammer to knock them down. I put a thick steel block on top of the liner to hit (not an idiot), otherwise you could crack it. When it seats, you know by the sound. If I did it again, I would sand the block more and use thin grease. I can't envision a liner shifting once installed, even with grease left between it and the block. The block surface isn't smooth and has small circumferential grooves.

I think any grease is too thick.
Even on the Detroit Diesel Liners that are a slip fit and will slide into place by hand without any sort of heating of the block or cold srinking of the Liners I believe even the thinnist grease would make them stick in the Bore.
I mean even if you used Differential Oil.

That being said what does the Factory Service Manual say to use as a lube?

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84 300D, 82 Volvo 244Gl Diesel

Ok, that's some contrary information...

Somebody want to bring in the truth of the matter

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