if you follow the below build thread the expert talks about the piston rings and improper rotation of the ring gap in relation to the others, during assembly. This will lead to carbon build up and deterioration of the iron coating of the piston, leading to the scoring of the Alusil surface. At what mileage do we expect these pistons and wall coatings to lasts? Does oil changes and proper use of the engine allow the engine to last when properly assembling the rings?

https://mbworld.org/forums/gl-class-...8-rebuild.html

I don’t buy the force fed tech being reasons for this technology to fail. Naturally aspirated porches and jaguars have had their share of scoring issues on coated cylinder walls with aluminum blocks.

And yes more parts are present on a turbo or supercharged engine, and added stresses are present, but not the definitive reason why they are unreliable.

 

The reason MB engines fail is MB's incompetence in the ability to design and produce a quality product. The mountain of evidence is astounding.

 

While one would suspect that regular oil changes at 3-5k miles would help, I couldn’t say that definitively. In my view the whole 10k mile oil change thing or CBS as BMW does, is rubbish and bad for engines and no one will convince me otherwise.

 

Agreed on the oil change intervals as a convenient way of marketing less visits to the dealer, while adding a longer list of items and expense. While lowering loaner cost to the manufacturer, is terrible. Yeah we hold more oil capacity, and have synthetic fluids, but there are other contaminants from the combustion process and fuels used that makes you think, do you want that running thought for 10k-15k. Viscosity and shear properties changes with use and contamination.

My Jaguar AJ50SC uses Nikasil as cylinder wall coating and that tech has had issues when fuels with high sulfur content is used, typical of third world fuels. How many people don’t follow these guidelines of using top tier fuels and the right octane, octane being detrimental to a force fed engine. Do people stick with 10k when the light goes on and run to the dealer or do they go just a little bit longer till they can get an appointment and make it convenient to bring it…equating to 15k intervals. Just a thought that’s all.

I guess luxury car owners want Ferrari and Lamborghini Performance with the reliability of a Toyota. Sometimes you gotta compromise on the expectations.

I dont disregard manufacturers getting wrong on a particular engine or component of the car. My wife’s Lexus IS has the amplifier in the trunk under the carpeting but near the vents under the bumper, it allows moisture to enter the space and causing water intrusion issues. I mean really!!! They could not find a better place?

Anyways. These cars are still mid life cycle. Where the initial owners have moved on. The second owners are still on extended warranties and could care less about maintenance cause they will get out of them when that is up. Then you will have the next phase of the cycle where rebuilding using cheaper alternatives used or machine shops will be more normal. For me if something does go wrong I will be on the latter camp. If it can’t be financially feasible to upgrade, I’ll sell the car for parts.

Knock on wood mine is in good shape without lights and noises. It’s not my only car so I’m not going to be in a panic if something happens.

 

Little bit know how...
Both AluSil and Nicasil engines die from piston coating wear. Piston coating wear last 75000 miles on average. Which means if you change oil sooner or later it won't last any significantly longer. Now by itself scoring is not causing misfire or compression loss that much to be diagnosed by ECU unless it been quite long and you engine is about to go kaput. As a matter of fact I had burned valves in my own engine and guess what no CEL ever. The check light went on after year of driving on 7 cylinders.
The only thing might help you to prolongate engine time is warm up. 10-15 minutes on idle to get oil warm. Reasons I explained long time ago.
Plus there is a complete carbon washing of the engine you can see some there on YouTube. However I haven't heard about this service in US.

 

http://lnengineering.com/files/2019-...er-Systems.pdf


For those that like a good technical read, take a lookx You can see how lubrication and warm up below freezing is of utmost importance for longevity of this technology. I don’t think these components are supposed to self destruct at low mileage. We are relying on the end user to do preventative measures for longevity. How do we expect that when we lack education on the matter. Lease owners don’t give 2 poop’s about the next owner after their lease is up. Secondary owners with extended warranties again don’t give 2 poop’s about preventing, they are covered. Shift the liability to the owners and bet their maintenance behaviors will change.

My recent Toyota 4Runner rental was loud, mechanical radiator fan!!!! unrefined, borderline unstable. It fit right in a safari excursion. It did the job. I bet it will last 200k without changing the oil ever. But has absolutely no soul, lifeless uncomfortable appliance.

 

Knock on wood, our 2015 550 has had 1 problem, with the active curve suspension and 1 problem with leaking coolant (plastic connectors). But the smell of burning coolant has been with us since we bought the car. Every time it comes in the garage, it stinks up the place. I believe German cars are so over engineered that major design flaws get missed. I had a Porsche Cayenne that had serious design flaws, basic dumb stuff like drive shafts that have to be replaced every 60k miles, coolant systems made of cheap plastic, spark plugs just inaccessible. Makes me appreciate my toyota all the more.

 

Interesting article. The article mentions molybdenum, which is essentially what Ceratec is, and how it can create a film to reduce wear and friction. My '13 GL450 is approaching 130k with no issues, I put my oil analysis on this forum and all wear was normal. There is a cold start piston slap but after seeing the oil report I'm more convinced its an exhaust manifold tap or faulty spark plug (noted on this site I think with CLS550). I use Ceratec in oil changed and elevated levels of molybdenum were observed.

Also RE gasoline, on Instagram if you type in #M278 you'll see many M278's in Russia having rebuilds and sleeves installed. Makes sense given their gasoline is likely high in sulfur and it is a cold climate, both of which encourage wear on the Al-Si.

 

So what is the difference between the Cera Tec and the MoS2 Anti Friction? Both are Liqui Moly.

Chad

 

I hear good things about the Ceratec. Can I throw a bottle in after a fresh oil change?

 

I believe Ceratec contains MoS2 and unlike the other Moly additive has Boron Nitride (hence the 'Cera' name). High boron levels were found in my analysis as well.

 

I throw in a bottle and a half after my oil changes. I know additives are quite a contentious subject, but I find it to be cheap insurance with some scientific backing. I wouldn't think it would prevent failures from the piston ring alignment induced cylinder failures, factory flaws, etc., but is a measure to reduce/prevent wear on the materials in most engines.

On that note the analysis also showed no significant deterioration in oil quality at a 10k oil change interval. I was considering changing to 5k given the mileage but after the analysis I'm sticking to 10k.

 

Sell it, my 2014 gl550 with 114k had multiple leaky injectors, heater core plugs up, rear suspension replaced and now cylinder scratches that require a new engine.

 

Maybe add the coolant overflow tank as a service item, there is a silica compartment inside that supposedly extends the life of the coolant. Problem is the silica let’s loose and might clog up the heater core behind the dash, and other components, requires back flushing or at worst case replacement requires tearing the dash out. I guess it doesn’t hurt to be proactive on this flaw.

 

20,700 miles and the cam followers are leaking.

 

151k on our 2013 GL550 no major issues but did have the cam seal leak into the harness. Instead of having major repairs we replaced the cam sensors to the new version and sprayed CRC QD elec cleaner into the harness. Let it sit for a day cranked up and the code still showed. Cleared the code and no issues over the last 10k miles.

 

Good to hear. I think most of us can deal with that failure. It’s the piston debacle that hurts feelings. Glad you got to that mileage with no lights related to scores

 

@Bill Baird Do you mean cam follower or a cam magnet or position sensor leak into the harness?

 

.

 

Just let them be normal closing door locks?

Don't yank the handle just after closing the door is also a good option. If you feel resistance to the door handle wait a few seconds for the soft closing mechanism to cycle or you will break it.

 

2012 W221 owner here. Vehicle History: 1 year CEO, 25tkm (15kMls), 8 years senior male (60tkm which is 5tkm per year or 3kMls). Annual oil change and MB service history thruout.
Needed to go a long way finding this and was super cautious regarding engine noise but was happy to find it in excellent condition at a MB dealership. Still under warranty, which i will extend until the car is 12yrs old in 2024. I was ultra aware regarding timing chain noise, oil pressure loss and rattling, long oil intervals and so on and quickly learned that if a seller doesn't want to communicate regarding stuff like that you better turn around quickly. Nevertheless, everything worked out well and i finally had the dream car i was admiring 15 years ago thinking it would be the pinnacle. Now, with the M278 being the even more powerful engine it would be now or never.

The evening after i bought the car was a pure nightmare. I transferred it to the town we live in (300 miles), went to a car wash. After finishing and a standstill of approx 60mins the car started but the timing chain was loud as hell. I thought u would faint. Anyways as history and seller were the best you could wish for i decided to keep my cool and just start communicating. Together with a bad auxiliary battery and a leaking seat cushion it was all taken care of very soon, they followed the Bulletin regarding the oil check valves and the chain tensioners. Dealership near my home town checked everything incl. timing with the diagnosis system and gave me a protocol - nothing is worn, just the rattle due to loss of oil pressure which has disappeard since then. I pre-heat the car before every drive and only use it for rides that are longer than, say 50 miles or sth. It is a factory installed Webasto parking heater which is quite common on euro cars. It pre-heats the engine so you noticeably dont have a real cold start. In summer that may not be such a thing, but we get temps below zero (yes in Fahrenheit, or -20 centigrade) for months here during Wintertime.

I am now 1 year in being an owner and have driven 6k miles with no problems whatsoever, had the large service 2 weeks ago and no extras besides a rattling air pump from the airmatic. Got a new bracket and suspension for the pump and thats it. Talked to the head mechanic regarding oil stop cables and the wiring loom and he said yes, he knows what I am talking about but no need for me right now.
The only special thing or investment i had was have them rip out the entire brake system. We have a lot of salty roads during winter and the calipers looked like from a salvage car. MB dealer disassembled them completely, had them powder coated in grey/RAL9006 color matching the original appearance and renewed all rubbers. When bolting the calipers back on i went the extra mile and paid for new rotors and pads though these were still okay. Now its like factory-new and safe regarding corrosion.

So, i would say if you know the basic failure scenarios for the engine and are super cautious, if you buy from a Mercedes dealership only or at least someone who is open regarding history and are 100% strict on getting a car with MB service thruout, the risk is minimized greately. For me, the fact that somebody would own such a car, drive it for only a few thousand miles per year and spend 1k for the warranty extension, 8 years in a row - shows me there was no need to save money and ditch an oil change or sth like that.

My personal outlook is: Own it, drive it reasonably, enjoy every drive and be aware that in 2030 ish years, you either can afford keeping this as a classic car or all of this will be history (here in Europe, especially Germany, you really need to have deep pockets to afford such a car - fuel, tax, social factors - imagine 10 dollars to the gallon. But: The reality of pulling on a highway being able to drive as fast as you want and simply experiencing a car like that in all its aspects is a once in out lifetime opportunity. I'm not YOLO but in this aspect its now or never.

Hope some happy M278 owners can chime in.

 

Wow. Eye opening. I have a 2007 GL450, issue free. Std MB maint, replace air springs at 110, rotors, etc. Uses NO oil. Rides very well, quiet. Bought at 50k now is 180k miles. Oh, oh, the various SAM modules are going bad due to water intrusion. One door rusty. I think I may trade to a 2012 GL450, because the X166/M278 stories are scaring me silly. Where there is smoke there fire, and the M278 is not the rock solid engine that the M119, et.al have been!

P.s., I have a 2018 GLC300 loaded - fabulous car, but has one turbo. Hope will be ok. Also have a 95 E300D with 280k mile. Interior like new, NO rust. Uses 4 0z oil per 1k miles, because front main bearing seal needs to be replaced. Replaced radiaror and water pump. The "mixing valve" was bad at 250k, which causes hard shifts, now shifts smoothly.

 

Have a read about the M274 2.0L DI turbo 4-cylinder engine.

 

I'll give my experience with 2x M278 cars.

1) 2012 E550 - was nearly flawless for 5 years from 65k to 106k. Only thing that went out was the AC compressor, which is common in FL because it's running all the time.

2) Current 2015 GL550 - Bought 2019 at 37k as CPO. Nothing wrong with the engine. I now have almost 70k. I recently did the trans service and spark plugs. I changed the cam sensors around 60k due to slight oil coming through. Easy $200 maintenance. The radiator had a significant leak recently and I changed it myself with Nissens brand for only $200. Took about 2.5 hrs of my time in the driveway. Dealer changed engine mounts on CPO warranty a year or so ago chasing noises in the front suspension, but that didn't resolve anything, but THANKS!. they also changed one control arm bushing. My wife still complains that she hears clicks sometimes when reversing and turning, like backing out of the driveway.

3) Recently purchased 2015 ML63 with 90k miles. It was not the best maintaned car, but I was determined to bring it back, buying it at a cheaper price. I have spent about $7k in repairs and maintenance. PO said engine mounts and coils were changed. I found a crack in the subframe under the left mounting point. Had to drop the whole subframe and have it welded up. Put in new engine mounts again, but mayber they were changed, not in bad shape. The coils definitely were not changed. One failed on me and I decided to change them all. When I pulled them out there were several different markings across the 8 of them. Did the spark plugs too.

Found pretty significant oil coming through the cam sensors, found oil at the main ECU connection. Replaced al 4 cam sensors, cleaned both ends of the harness, haven't had any problems

Had an issue with the boost control solenoid on top of the engine, was getting codes for over or under boost. $75 OEM part remedied that, very easy, but I had to do some vacuum testing to figure it out.

Radiator on this one also started leaking from separation, paid Eurocharged $1300 to replace with OEM radiator

Had an issue with the active suspension front hydraulic block, replaced with used block for $200 and some fluid, now it's fine.

The engine in this one is totally great, nothing wrong with it. The M157 is the big brother of M278, basically just a stroked out version of the same engine from 4.7 to 5.5L


So, in summary, just be sure to change the cam sensors before the oil leak-through becomes a big problem. I bought them all from FCP Euro, so if they leak again, I will get free replacements for life! Also change the spark plugs with correct plugs and torque every 60K and maybe just replace coils as preventitive maintenance, that's very common with my previous Porsche Cayenne, doing plugs and coils at preemptive intervals. These engines are actually great. I love the torque curve of the M278. Now all the peripherals of the ML/GL platform can be questionable. Mainly front suspension creaks that are never resolved. The dynamic suspension hydraulics can fail, but it's an easy system to work on. I fully expect issues to come with the air suspension, but it's nice.

 

Honestly, the biggest problem in the m278 seems to be the coolant system. Brittle plastic that starts cracking after 100k in multiple places. Heater core inlet/outlet, turbo coolant lines, radiators that spring leaks. It's not even the cost that bothers me anymore.... Just the lack of reliability and constant trips to the shop, much worse than my experience with other auto makes. Add to this the complexity of any DIY, it can turn into a nightmare real quick.

I can handle failures of any system but not the core drivability. I have a policy of buying any brand only once.... I'm glad I'll be leaving this brand soon.