GL Class (X166) 2013-2015 after facelift became GLS (X166)

M278 Rebuild

Old Dec 5, 2021 | 06:09 AM
  #51  
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2014 GL450, 1992 W140 300SD, 1993 W140 300SE, 1987 E30 Convertible
Installed pistons by using this tool. Much easier and more convenient that ring compressor. Still waiting on one last main bearing. Crankshaft has zero wear, installed stock size mains with no coating (coating makes too tight). This week machining heads






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Old Feb 17, 2022 | 10:12 PM
  #52  
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2014 GL550
Is this your shop? Do you service these aside from a few personal projects?
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Old Feb 17, 2022 | 10:18 PM
  #53  
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2014 GL450, 1992 W140 300SD, 1993 W140 300SE, 1987 E30 Convertible
That is my garage. I do custom machine work from time to time. If it a solution for your problem i can sleeve your block with custom ductile iron (racing) sleeves and hone it to standard piston size, however wait time on those sleeves is about 2 months. Right now i am waiting on my set for this engine, put cast iron sleeves, didn't like it at the end, so decide to do solid on this project.
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Old Feb 17, 2022 | 10:38 PM
  #54  
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2014 GL550
Did you noticed anything unusual on the heads, bent, cracked, non seating valves? Bad guides… are you working the heads too?
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Old Feb 17, 2022 | 10:54 PM
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From: New Orleans
2014 GL450, 1992 W140 300SD, 1993 W140 300SE, 1987 E30 Convertible
I do complete rebuild. Not quick fix or swap.
Valve guide story is a BS excuse to avoid another law suit. Valves on 5th cylinder goes out because of overheat from turbo proximity. Simple as it is.
Camshafts and rocker arms wear out close to 100k. Just normal situation. It is the way they constructed. Try to find used camshaft in good condition on ebay ))))
Most of the people expect life time longevity, however market shifted toward "suppose to be able to afford swap a car after 70k miles"
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Old Feb 18, 2022 | 02:48 PM
  #56  
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From: Schenectady, New York
X166 blue tec 2014 / 2009 Toyota Venza
Originally Posted by arsupisemnet
I am going to follow another M278 complete custom rebuild. Donor is a "coffee table" by some of the forum members with about 40k of mileage.
are you doing the rebuild or having someone else perform this amazing feat?
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Old Feb 18, 2022 | 09:14 PM
  #57  
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From: New Orleans
2014 GL450, 1992 W140 300SD, 1993 W140 300SE, 1987 E30 Convertible
I am doing rebuilds and machining myself...
​​​
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Old Jul 28, 2022 | 10:40 PM
  #58  
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G80

Dear arsupisemnet.
I`m a mechanic in Korea. Excuse, I want to inquire where you get this parts.
Would you reply to me by email please? My mail is 'jincar8179850@gmail.com'.
I`m looking forward to hearing from you. Thank you for your help.
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Old Oct 5, 2022 | 10:33 PM
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gl550
GL550 2015

Hi, I have a problem with cylinder #5 on GL550 2015. Can you replace sleeve? Or may be you could recommend some one in NY. Thank you.
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Old Dec 5, 2022 | 03:47 PM
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2017 gls550
Sleeve

Where did you find the sleeves?
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Old Dec 6, 2022 | 05:02 AM
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From: New Orleans
2014 GL450, 1992 W140 300SD, 1993 W140 300SE, 1987 E30 Convertible
Custom build
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Old Dec 6, 2022 | 05:08 AM
  #62  
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From: New Orleans
2014 GL450, 1992 W140 300SD, 1993 W140 300SE, 1987 E30 Convertible
How much it usually cost to rebuild this motor.
To put cast iron sleeves - 2000 (including sleeves)
Ductile iron sleeves will cost you 1500 more and month of wait time to get them manufactured
Bearings seals and gaskets will go around 1000
New piston go for about 300 from MB, or you buy without skirt damage at 140 from eBay and another 50 to get it recoated plus shipping makes 200 per cylinder.
There is Chinese rebuild kit for 1600 at eBay - but you are on your own, i would not risk buying it
Timing chain components (if decide to replace) goes for about 700
Heads overhaul will cost at about 1000.

Last edited by arsupisemnet; Dec 6, 2022 at 05:10 AM.
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Old Dec 6, 2022 | 06:26 AM
  #63  
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Originally Posted by arsupisemnet
How much it usually cost to rebuild this motor.
To put cast iron sleeves - 2000 (including sleeves)
Ductile iron sleeves will cost you 1500 more and month of wait time to get them manufactured
Bearings seals and gaskets will go around 1000
New piston go for about 300 from MB, or you buy without skirt damage at 140 from eBay and another 50 to get it recoated plus shipping makes 200 per cylinder.
There is Chinese rebuild kit for 1600 at eBay - but you are on your own, i would not risk buying it
Timing chain components (if decide to replace) goes for about 700
Heads overhaul will cost at about 1000.
$7k-$8k in parts + labor?
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Old Dec 6, 2022 | 06:33 AM
  #64  
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That is including labor, i would through another 1000 for putting motor together and 2000 to put it back in the bay
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Old Dec 6, 2022 | 06:34 AM
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2014 GL450, 1992 W140 300SD, 1993 W140 300SE, 1987 E30 Convertible
Sleeving price - that is an average american v8 price. No markup for being MB no liability charge
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Old Feb 10, 2023 | 01:29 PM
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2011 Mercedes-Benz CL500 4matic
Hi, @arsupisemnet sorry to bother you, but i can't send a direct message.

I'm rebuilding M278 in my CL500, can I ask you few things about it? It would help me a lot. Thanks in advance.
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Old Feb 14, 2023 | 10:59 AM
  #67  
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Originally Posted by arsupisemnet
Filing appropriate thermal gap in piston rings. Once again i used Mahle 41930CP piston rings. Assembled oil ring in kit is 2.5mm thick, when original MB 2mm thick, so all you need to do is to clean and reuse oil spring ring to match thickness. There is an old school trick with installing oil rings. When you squeeze oil ring it tend to flex in certain direction as shown in picture. And that is the direction toward piston crown shown with arrow. In this case top oil ring will be scraping oil away from compressional rings and bottom oil ring will be scraping oil toward piston skirt keeping it lubricated.


Can rings from this set be fitted into iron cast sleeve?

https://www.ebay.com/itm/23364333285...mis&media=COPY
Again sorry for bothering, but I can't pm.
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Old Feb 14, 2023 | 11:28 AM
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Don't know. I gave a reference number to exact match before, only thing you would need to reuse is oil expander for oil rings. But by judging by the price i would say - those are diamond coated, they will chew up your iron sleeves like butter.
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Old Feb 14, 2023 | 03:02 PM
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2011 Mercedes-Benz CL500 4matic
Originally Posted by arsupisemnet
Don't know. I gave a reference number to exact match before, only thing you would need to reuse is oil expander for oil rings. But by judging by the price i would say - those are diamond coated, they will chew up your iron sleeves like butter.
​​​​​​Thank you very much, I really appreciate the knowledge.

So I should use Mahle 41930CP - rings for Cadillac? Is it right? Like these below?
https://www.ebay.pl/itm/385412123073...mis&media=COPY
Is there any other spec I need to know? Or these rings will fit straight from the box?

Again I am sorry to bother you.
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Old Feb 14, 2023 | 09:49 PM
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Go through the posts, it has all the information you need. You need to reuse oil ring middle component to fit original pistons and set vertical gap (but that is standard procedure for any proper engine build)
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Old Mar 2, 2023 | 04:54 PM
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W204
Hi,guys! I'm new to the forum. I have question about the main bearings produced by King. I can't find them. I have a small engine rebuild workshop. We are rebuilding engines like that and use an oe std main bearings, but now I have to regrind the crankshaft main journal. My email is ganis@abv.bg
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Old Mar 2, 2023 | 08:48 PM
  #72  
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None available, there is no repair size main or connecting rods bearing being manufactured. So either substitute from other engines or get new crankshaft.
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Old Mar 30, 2023 | 01:46 AM
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w166 ml550
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Originally Posted by arsupisemnet
Filing appropriate thermal gap in piston rings. Once again i used Mahle 41930CP piston rings. Assembled oil ring in kit is 2.5mm thick, when original MB 2mm thick, so all you need to do is to clean and reuse oil spring ring to match thickness. There is an old school trick with installing oil rings. When you squeeze oil ring it tend to flex in certain direction as shown in picture. And that is the direction toward piston crown shown with arrow. In this case top oil ring will be scraping oil away from compressional rings and bottom oil ring will be scraping oil toward piston skirt keeping it lubricated.


How much gap did you leave
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Old Mar 30, 2023 | 08:27 AM
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w166 ml550
Andrus

How 3.659 have enaugh clearense for piston?

Originally Posted by arsupisemnet
Final bore 0.003 under final bore size of 3.659 inch. After that will be honed to final size by using diamond stones.

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Old Mar 30, 2023 | 10:06 AM
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Your machinist suppose to measure pistons, add clearance and hone individually for each piston size. In my case i had this size because i had original MB pistons with racing coating by professional company.
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