I’ve got 95k on my ‘ticking time bomb’. And my mechanic just posted a M157 with +180k miles getting routine service. These engines may not be bulletproof…but they’re pretty damn close, considering all of the applications. Someone mention the N63 motor from BMW. I’m intimately familiar with that one. A worse experience than I had with my Oldsmobile Quad 4 in the late 80s/early 90s. And I didn’t think that could be possible…

 

@C2 Turbo No data. It doesn't exist unless you work for MBUSA or Daimler, and I do not work for them. Neither side of this debate has data, it's a judgment call all around the campfire. Pass the marshmallows and graham crackers, please.

No one has claimed anything is exploding except in your post above.

 

This is a "popcorn worthy" thread. Really sorry for the OP.
Are cars less reliable today than 30 years ago? Absolutely not.
Are cars more complicated and cost more to fix when they break than 30 years ago - you bet!
Are we as customers asking for this? Well, partially. We want high fuel efficiency, crazy fast family cars with all the luxury features. That circle is hard to square.
Layer on top that such huge percentage of cars are leased - money is cheap to borrow - and the practical lifespan of car in the eyes of the manufacturer becomes 3, maybe 5 years.
The GOOD news is that if you are comfortable doing some small work yourself, and you are ready to potentially bite the bullet for a major failure (or just walk away), you get these off lease, awesome cars, at 40-60% off (well, at least before Covid). Not bad!

 

perfectly put

 

It's all good. I'll keep you guys posted on developments. SF Benz has the motor (I was told there was one in Fontana when I started this ordeal, I assume that's the one they got.) Hopefully going in next week. I've started to increase pressure to get work done under warranty limit (as well as a suspension creak I want taken care of).

 

In response to your squeak - check out this thread:

They all do that....

 

My previous mechanic is in the process of replacing another stock tuned M157 engine with 90k miles also having a cylinder #5 loosing compression. Another one bites the dust

He was an AMG certified tech at a local dealer. He said it's not isolated to the M157, the M278 and one of the 4 cylinders (can't remember which one) also had the same recurring issue. Apparently the nano coating start to get scratched and eventually whole cylinder looses compression. The issue is why that happens....not very well understood.
Theories include
location of cylinders that go bad to the turbo (in the v8s, you can see the turbo vanes through cylinder 5 exhaust port). Some.backfire going back into cylinder 5 and with time, coating scratches off to where compression and leak down fails.
Connecting rod having a slight bend with time from bad injectors (all the cars mentioned above use the same part number for injectors). Some knock from injector not functioning properly or overflowing at low enough rpm. Eventually walls scratched compression fails etc etc
Anyway those were his and the AMG reps theories. They has a guide with pictures showing allowable levels of scratches on the cylinder walls. And what was considered excessive.

 

Tuned? I don't know if this matters or not, after i come home from a drive, I always open the hood to let the heat out. The dang thing does get very hot even after a short unspiritied drive.

 

I don't mind replacing my engine at 90k miles and re tuning... I won't get a better car for the ~$25,000-30,000 it'll cost to get my E63S up and running with 100 octane tune. $0.02

 

Yes, there are posts in the W212 and GL sections of this site with cylinder coating failures.

 

Seems like many clueless and misinformed people on this section.

I agree engine failure should not be considered normal or an OK event for these type of vehicles with high costs, however it’s common across the board on all European V8s. (Actually most European makes and models)

I had a bunch of F10 m5s and those motors blow left and right from rod bearings to leaking injectors. I also had a 750li with the n63, that’s another terrible motor. I had leaking valve stems burning oil every 200 miles. Bmw fixed it under a class action suit. The f80 Ms had a problem with the crank hub. That’s why I left BMW. And I was extremely tolerant and forgiving with them and gave chance after chance with their N54/N63 problems that I endured. The 4 cylinder BMWs also have a terrible timing chain problem which blows the engine (n20 motor).

Audi has terrible problems with its V8 TT cars with its turbos and oil screen issue. Turbos will blow, many have caused engine damage. Oil consumption is crazy when that happens. Audi also has problems with its 2.0t, timing chain, oil rings, etc.

Land Rover/Range Rovers/Jaguars from 2010-now (5.0 NA, 5.0 SC, 3.0 SC) has issues with timing chain due to factory suggested 17k oil change intervals. Timing chain guides wear out which will cause engine to blow once the chain lets go. In addition to the timing chain there is a coolant pipe located under the SC that could literally let go at anytime resulting in engine loss. Most people will get overheat warning, by the time they pull over, the aluminum engine is toast. This issue effects every model from 2010 till now. I see posts every other week on FB with someone buying a used model or someone’s wife driving overheating and it cooked the engine.

Beloved Mercedes M157/M278 has its issues as well. The common one being the faulty cylinder 5 valve/guide with low compression. The next common one being engine oil screwing up the wire engine harness. I spent a good few hours on cars.com and other sites looking at carfaxes on higher mileage Mercedes V8 TT. Both these issues popped up frequently on the service history.

However I also saw many of these m157/m278 with over 200k miles on them. Just like I see many Land Rovers/RR over 200k running amazing (not joking).

I DO WISH there was a easy way to tell and avoid the low compression/cylinder 5 issue on the Mercedes V8 TT. It seems it is a total guessing game and no real way to prevent it or avoid it. With the other makes prevention is easy. On the RR change your oil frequently, change those coolant pipes after certain mileage. BMWs at least on the s63tu, I had all my injectors changed to prevent any leakage and ran black stone oil reports frequently for bearing wear. On Audis I have friends changing the oil screen before problems start.

Anyways that’s my two cents. As you can see all models and makes from Europe have problems. These are just the ones I have heard about/seen due to owning these vehicles or having friends with affected models.

 

but when they run, they make us happy right? It's the price you pay for happiness.. ymmv

 

Absolutely. And in my case when people see the MPG on my G63 (5-6 on average day, 11 on a really good day) I tell them it’s all about the SMG (smiles per gallon).

In all honesty I always do and suggest everyone to get a reputable exclusionary extended service contract on these cars. It will cost you 7k-12k (these are the figures I paid) but at the end of the day one big repair and it pays for itself.

In a perfect world we’d have Toyota like reliability with mind blowing performance like we get out of these amazing V8s. However we need to remember that we DO NOT live in a perfect world....far from it.

Anyways my input to this discussion. These type of threads exist on every make/model. Costly repairs are a part of life. Even Honda’s and nissans are not immune tbh. I had injector failing problems which caused many messed up motors on 17 CRV and did everyone forget nissans CVTs? Lol

 

Good rundown. BMW seems to have a good engine in the B48, successor to the N20. It's doing well several BMW models. What is your take on the Porsche 4.0L V8? Not many complaints so far in the 9Y0 Cayenne section of Rennlist.

Regarding oil in the harness, this comes from failed cam position sensors, cam solenoids, or both. The remedy is to replace all 8 components (4 x sensors, 4 x solenoids) with the latest part number. These are MB parts bin parts, shared across 4, 6 and 8 cylinder engines. Checking these 8 connectors for oil should be regular preventive maintenance. A small amount of oil is not fatal, CRC contact cleaner takes care of it on the ECU end, and the 8 components should be changed if oil is found. If an egregious amount of oil entered the harness, and hasn't contaminated the ECU, a new harness and new sensors+solenoids are the fix. In the worst case, replacing the ECU, harness and 8 components is also a fix. Oil in the harness in the worst case scenario should cost far less than a new engine.

 

I love this rational discussion!!! Keep it going

 

I really wrote off BMW after my last 750li and one of my F10 M5s. I did feel frustrated by their lack of concern with the issues those models had. I was told by a few dealers and a few bmw NA reps that the higher end M models and 7 series are built for the customer who leases/dumps their vehicle after 4/50k. They really don’t care about anything after that as most of their “valuable” customers just dump them and buy the newest thing.

In addition to that I also noticed the new F90 M5 having the same injector issues the previous generation did. Same story with some of the new 16-17 7 series were also having oil burning and valve seal issues after 50k miles. At one point I was driving my 7 with 8-10 quarts of oil along with 3-4 bottles of coolant in the trunk. One trip that’s memorable from Chicago to NYC I added over 15 quarts of oil and 3 bottles of coolant. After the class action bmw did do right and replaced the valve seals, along with turbos and did a whole overhaul of the cooling system for free. I retired the vehicle with 135k miles and last I checked it was still running strong with the new owner with over 180k miles with no more issues lol go figure. One of my f10 m5s experienced catastrophic injector failure with one injector being stuck open while doing a WOT pull at around 90 it felt like I hit a brick wall. The vehicle was then underivable. The failure happened on the west side highway in Manhattan during as peak rush was starting. No tow service from BMW assist was able to get to me there as the city has a contract with only a few towing companies. I limped the car (turning it over driving 2-3 miles with raw gas spitting out the back before it would shut off and repeat) until the nearest local road where they came get me. After they replaced one bank of injectors they did a compression test and said “you are all good”. Now most people that had such an event would have either their motors hydrolocked from raw fuel being dumped into the engine or a few thousand miles have a bearing go from the same event. I traded the car for a big loss and promised myself never to go back to BMW.

Thanks for the information for the oil harness. That is good to know.

Porsche is one make I haven’t owned. Every time I was close to adding a Porsche to the fleet I ended up with something else. However they aren’t immune to issues I do remember when looking at the 996 the IMS bearing issue. I also recall when looking at a 12 Cayenne/Panemera Turbo I read owners complaining about spun bearing issues and one 12 Cayenne turbo I was purchasing ended up spinning a bearing while at the selling dealer. I also remember some interesting weird issues on the early Macans with their transfer cases and some scattered PDK failures.

In the end the way I look at it is that vehicles in general are complex machines. No matter which machine you choose you have the likelihood of having some gremlins and issues. Some might have more than others and others might not have any or just a few. I think the mindset is European vehicles are known to be expensive and costly to maintain. So people freak out and make a bigger deal than say CDJR or GM product. It doesn’t help that most local shops and garages do not have the expertise or knowledge to work on many European vehicles compared to say a domestic or import.

Side note for MB: In NYC we have dozens of S550s that are pretty much taxicabs. These vehicles are part of large fleets and driven hard and aggressive, long idle hours and wear and tear. I had a friend who owns such a fleet and he said in his line of business they will take the s class over a 7 or A8 any day. He said they tried experimenting with other high end sedans but they always come back to the s class. Reliability wise and long term overall reliability he said the S class is the king.

 

It's a TT with gobs of power purchased by enthusiasts that wail on them. Stuff is going to happen.
Throw in the type of nut that pays as much as we do to have this kind of power and daily drive it. Well, that's the FIRST screw that's loose in this whole equation LOL. Who buys 600HP station wagons and sedans? Nutbars do LOL.
So we have to add in that the WOT and FULL POWER happens a lot more then a normal commuter car because of the nut behind the wheel.
Then add in that these nuts found each other and congregate on forums. Grandma with a '63? Not that common, never mind on a forum.
So what we read here is skewed, on top of the demographic that buys these things, on top of the fact mechanicals are stressed a LOT more then some commuter Toyota or Lexus turning 3,000 RPM's or less their whole life.

I think for what these things do in all the different environments all year long every day it is AMAZING. Even when they pop. Don't agree? Go buy a boat. Engine life is measured in HOURS.

What a wonderful time to be alive! 10s and 11s in comfort, not a ragged out racecar that has to be towed to the track.

LOVE IT

 

perfectly said!!!!

that's why I'll buy a new engine when this blows and I don't care about m157 failure stats - it simply makes me happy - how many things in life do that - make you happy?

also if you're going to get caught up on failure stats then buy a Camry

whats the saying - can't have your cake and eat it too?

 

Yep. I can't believe how much I <heart> my car. Occasionally I think about trading on a 4.0 wagon, but, haven't yet. My old school brain just doesn't want to give up the 1.5 liters.

 

I have blown an engine and almost bought another M157. The problem is I could not see the point of doing it again when I was just faster than stock. Obviously, this was in the pre TCU tune days. Now, I would have been looking at a Tasos-built engine (sleeved etc, what coating???) and only worry about blown trannys

That being said......the new 4.0s are beastly, even torquey than the 5.5s (stock vs stock) and yet revs so much easier and faster than the lazy revs from the M157. Trans is much smoother and shifts much faster. Maybe I will find out what makes the M177 blow in a few years lol

 

My 2 cents on the Cylinder # 5 debate; I have a mercedes m157 engine (5.5liter bi-turbo) in my short commute, daily driven ride. I bought the car with 50k miles with fresh dealer oil. at 55k i changed the oil and put a cheapo boroscope into cyl 5 (known to be the first cylinder to show wear)


and as you can see there is some minor scuffing.(1st image at 50k, 2nd image at 55k) At 55k (1 year later) I did a 2nd oil change. again I did the boroscope and got the 2nd image with notably more piston scuff. I was running Liqui Molly 5w40 leichtlauf. I also ran a mild tune for 4k of the 5k miles. I've now pulled the tune and am sending a sample to blackstone. I'm not looking for magic but if an additive could slow down the rate of damage I'd like to try. I'm interested in the Liqui-moly Ceratec or MoS2. I'm in a colder climate (ny state) and have read that some suspect (mostly porsche owners that seem to be having a cylinder scoring problem) that when cold, the piston warms and expands faster than the aluminum cylinder and can cause this. I'd welcome any thoughts...Thanks for reading!

 

Great commentary and data/photos. My view is MB cheaped out on the cylinder surface treatment. It’s an expensive part of manufacturing the engine. Differential thermal expansion is less likely in my view.

If someone can post cylinder diameter and tolerance, and piston diameter and tolerance, for M157 vs M156 that would be interesting.

 

Could also be from the piston coating wearing off. You need to run dissimilar metals in an engine bore or you will see failure and scuffing. Once the piston coating wears off, you have aluminum touching aluminum and that's not good.

 

I believe this is generally my points way up the list here!

I agree with this message. 😉

 

My man!
How’s that estate beast? ALP still workin? Brackets holding up?
Cheers bro.