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I have a 2014 GL 450 that i need to rebuild. Ive seen two ways advertised to pull the powertrain. One by dropping the subframe and the other by removing the front clip. Which do you recommend? I would love to ship you my engine for repair. My email is mrricojam5@gmail.com
What do you ran for rings clearance? Do you have manufacturer specs? Would like to know what is the factory clearance.
thanks,
Jasen
Originally Posted by arsupisemnet
Now the most important part of the day!
Why this particular engine failed?
The answer will shock some of you.
Improper assembly of oil rings.
This particular pistons have three part oil rings. Top scraper, middle spring, and bottom scraper. In general it is taken to have these rings gaps to be rotated either 120 degrees between or 180 degrees between spring gap and top and bottom scrapers.
In this particular engine in cylinder 3 all three components of oil ring being aligned together, basically making this oil ring useless. As a result an excessive amount of oil leaking inside of the cylinder, leading to extensive carbon buildup and as a follow a cylinder wall damage.
Cylinder 7 got damaged because it share same crankpin and carbon buildup from cylinder 3 was falling into crankcase and being sprayed on the inner surface of cylinder 7 by spinning crankshaft.
Cylinder 1 had bottom scraper gap aligned with spring gap resulting in less than 100 percent performance ending up in same carbon buildup and excessive wear.
So as an advice if in case you are having issues with premature engine wear-out and you are out of warranty please video engine disassembly process. If in your case you will find out same situation where oil ring improperly assembled you might have a legal cause (with a lawyer of course) to get your car repaired at the expense of car manufacturer.
An example of proper piston rings alignments
I am machine shop, which doing these kind of engines and so on, located at New Orleans.
Hi, I have a 2013 GL550 torn down. I've been looking for a decent small block, but I'm not having any luck. If you sleeve these, I'd like to send it to you.
Can you be more specific about? If you want me to sleeve it, or rebuild it, or I will have another short/long block ready in couple weeks.
This is how it is going to look like (just an example this one already sold)
To sleeve your block it is 2k including cast iron sleeves. I need pistons you going to use to do it because I will match every cylinder to piston size.
Short block goes for 5k, long block goes for 7k, 300 shipping, will refund 1k if get core back from you.
Contact is arsupisemnet at gmail. Block sleeved with cast iron sleeves, has coated MB pistons and appropriate rings, polished crank, new bearings, seals...
Do you run any kind of aftermarket boost?
@arsupisemnet If you dont mind me asking... Can I use 157 shortblock / rotating assebly and just slap the heads and timing parts from 278? Can you see any problems with this? Thanks!
Good morning
I don't function on any forum on a daily basis, but this is the first time I've been curious about the approach to the issue. On a daily basis, I have a company that deals with engine repair- but of large power, mainly in the railroad industry.
I would like to ask, because I see that you have a good technical approach to modern engines and experience- and the industrial engine industry has another technology.
I used to have an M278, but it didn't fail at all - sold at about 70-80k mileage.
A good friend of mine imported a 2014 GL450 car from the US, mileage about 110k.
After a body repair, he drove about 1000km and the engine stopped. Due to the fact that I have mechanics I took the engine apart and checked what was damaged.
The damage, of course, as in your case.
I ended up replacing the engine with another one. The second engine Prophylactically was taken apart because I noticed with an endoscope that two cylinders have the beginning of this typical problem performed inspection of the pan, checking and cleaning of the pistons, replacement of several timing components (tensioners, etc.), new seals, measurements of the heads, replacement of several additional components including the valve on the oil pump with the harness.
Inspection done quietly-no time pressure.
The engine was mounted to the car, the cooling system was filled (vacuumed, of course), started, oil pressure checked with a timer in the cold, warm and driving phases. Pressure in the range of 1.5-4.3 bar, depending on ECU injection.
After about 100 km, the engine damaged at idle after a short drive. According to the endoscope damaged 5 cylinders- has not yet been taken apart.
Moving on to the question.
Are you sure about the theory of the location of the rings on the piston?
In both your case and mine, the pistons are damaged at the bottom which could indicate a problem in piston cooling. Both cooling on the side of the cooling system and a possible defect in oil spray through the oil nozzles.
I ask because I wanted to help a friend and I got myself into a bit of a conundrum. I've read reviews in the past that engines have a problem with oil pressure replacement, I've looked at this system and theoretically it should work. I've also heard (without confirmation) that the GL model has a much higher failure rate for this engine than the other Mercedes limousine models.
Do you have any experience regarding these threads?
I'm wondering if a defect in a certain component (both in the engine and in the cooling system hardware on the engine side) may be causing the cooling system to be vented, which may be impossible for the engine controller to pick up.
I'm sorry that I wrote so much, but I wanted to clarify the issue. We in the company repair engines from 500 to 3000 kW, so automotive solutions are foreign to me.
Pistons alway damaged at the bottom because it is wider in diameter. Piston cooling has nothing to do with damage, actually it is better with it.
Oil pressure is an issue if your harness or control valve on oil pump is not functioning. It will lead to bearing spun and engine lock
Overall it is as simple as it is. Turbo -> Blow by -> Excessive carbon from burning oil -> Abrasive wear of skirt coating. Some of the engines has improperly assembles oil rings which lead to more oil around piston -> more carbon.
For other models - some models has Alusil sleeves engines, some models has Cast Iron sleeves (very rare). So is statistics. Also i believe that some of the MB replacement engines came with cast iron sleeves.
Amazing thread incredibly detailed! I have a 2013 GL550: I replaced my engine 6 months ago it had 86k miles with one with 52k miles. 6 months passed and started misfiring again and found the scored cylinders. Will need to replace again. Do you upgrade these engines and sell them? If so how do we get in touch? Look forward to hearing back.
Yes, its still running but will need to replace. I have this current engine under warranty that they're going to replace for me. Do you have a way of contact maybe via direct email?
07-16-2023, 08:24 AM
X166 M278
