M156 engine repair nightmare

[gsxr]

2014 C63 with less than 3000 miles... had accident damage, and the engine was repaired incorrectly. Someone swapped on a lower main bearing carrier from a different engine - can't do that! The crank bearing journals are line bored!

Ignore what the guy says about this being a flat-plane crank. He's misunderstanding what a flat-plane crank is... that defines the rod journal location, NOT the counterweight location.

Cracked crankshaft was a free (ok, $7k) bonus find. @jhodg5ck , maybe they'll contact you and @Klink to save this disaster, lol...

Jono, are bad M156 engines that common? The other shop said they bought 3 used M156 engines and they are all "bad", but didn't elaborate.

Mercedes AMG engine nightmare​

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How someone that doesn’t know what they are doing can make things so bad. Just because it can bolt together doesn’t mean it will work. A cracked crank and a ruined block​

 

[jhodg5ck]

I've bought 4, every one has been Great. So maybe I'm just lucky..

The bad engines we have seen, someone ignoring a bad tappet, running till it dropped a valve "been ticking for a year maybe"

fellow tried to "clean" his own injectors. Stuck 4 of them wideopen. Hydrolocked the engine on fuel....

Another prominent shop south of us installed a set of studs, didn't do so properly. Popped head gaskets. a number of studs came out With the nuts when we were taking the engine apart...Whoopsie.


I've got 2 spare cranks, some extra heads, cams, intakes, exhaust manifolds, oil pumps.... What cha need?!?

jono

 

[daantjie]

Apparently the M159 evolution did not have the common issues found on the M156. True?

 

[gsxr]

Apparently the M159 evolution did not have the common issues found on the M156. True?

I forget when M159 production started, but most of the M156 issues were sorted out by about 2010 or so (head bolts, cam phasers, etc).

 

[AMG5PT4]

Hard for me to believe that they can't find a used motor with a good lower end to pair with the nearly new pistons, heads and top end. It would be rare for lower end M156's to be junk (three of them!). The weak spots on these motors is on the top side - camshafts and head bolts and intake manifolds. They need to look a little more.

 

[duuder]

this was not a 65k dollar engine when it came out, it was more about 30ish... the M159 had all the nice, BS parts in it

 

[gsxr]

this was not a 65k dollar engine when it came out, it was more about 30ish... the M159 had all the nice, BS parts in it

Yeah, I was wondering about that number. Maybe MB jacked up the prices due to NLA, lol.

"Hey, if some fool will pay us $65k, we'll build one for them!"

 

[Klink]

Apparently the M159 evolution did not have the common issues found on the M156. True?

None that I know of. But a shocking(?) number of M159 engined cars are absolute garage queens with a couple thousand miles on them, so if they have their own issues, it's conceivably too soon to tell. My completely personal opinion is that they should be relatively free of lurking disaster faults because they were developed well past the warranty experience learning curve of the M156, AND the 159 gives every impression that they had the accountants heavily sedated while they tried to make a perfect engine.

 

[Klink]

Yes! I was questioning at least the engine theory expertise of the guy that was so confidently pointing out the characteristics of a "flat plane" crankshaft on an obvious cross plane crankshaft.

Just damn, internet! The "flat crank" madness has to stop already! Every engine that somebody thinks sounds good gets called a "flat crank" now, even if it doesn't have a cylinder count that can be made into a "flat crank" It's full on mass formation flat crank psychosis everywhere!

Now, here's what really chaps my ass from hell to breakfast about that. You know what the very best thing is about a M156/159? The very most distinctive part about it compared to most other performance oriented V8s of the era? Ok, I'll tell you: THE DESIGNERS HAD ENOUGH INTEGRITY TO BUILD A PROPER FU$@ING PASSENGER CAR V8 INSTEAD OF TWO BUZZY INLINE FOURS ON A COMMON CRANK!

Yes, there are some engineering reasons for flat cranks on certain race engines when attempting to exploit certain rules and layouts, particularly regarding the induction and exhaust streams. But in the absence of such imposed design strictures, they are in most ways inferior to a cross plane V8.

The hummingbird 8s are being done ad nauseam now simply because of the sound. And people are only attracted to the sound because it is "different" There's no way to know, but I think that if most passenger car V8s had already been flat cranks people would now be gushing over the sound of a cross plane. There's even possibly something subliminal to the appeal as it (probably subconsciously) reminds some inner children of the flatulent little penalty boxes that they'd already been driving for the last few decades. I didn't mind Italian exotics doing it so much because some of those stood a chance to be turned into genuine race motors, and a flat crank could become more desirable in that context. But the proliferation of flat cranks in street cars now has only two arguably excellent purposes: One is that the sound helps sell the cars. The other is that this same sound simultaneously warns all within earshot that they can't possibly get far enough off of and/or away from the road if they don't want to suddenly resemble pizza...
#flat crank casualties

 

[JC220]

@Klink Good to see you posting

I was away for a bit also with work etc but I will make time for my cars this summer.

Re Dave's you tube channel I only recently discovered it and I like it. Generally speaking they seem like a good shop for the diesel merican engines. The AMG motor here likely is something they never see so I'll give them a pass on it.

 

[duuder]

forgot to mention but theres an interesting theory about cars with head bolts being from climates that have hot/cold seasons accelerating the issue

 

[Ertech]

don't forget real shitty sealing on the upper oil pan , full engine teardown to fix .
intake manifold leaks , bad throttle body housings, horrible oil vapour system, cams made of butter ....

 

[AMG5PT4]

Plus horrible metallurgy on the cam phasers impacted by the hardened steel pin. IM made of magnesium vs aluminum might save 2-3 pounds or so, but a horrible metal to use when exposed to air, gas, oil, heat. But, my 09 E63 is my daily driver. I have dealt with the above gremlins, added an air/oil catch can and a new rear main seal. Hopefully, my "spare" $16k or so will allow me to enjoy the car for an extended period....

 

[jhodg5ck]

I forget when M159 production started, but most of the M156 issues were sorted out by about 2010 or so (head bolts, cam phasers, etc).

ehhhhh...ish. Head bolts are entirely hit of miss. I know of 07's with over 150k on original bolts. I know of Late/plastic valve cover engines popping before 75K.

Phasers IDK, I haven't had a new set go Bad but I've seen late stock phasers act up..

Anyway, there are fixes for all of that and if you dive in Before it's not harteful IMHO... especially compared with your 278/157 that blows up just for Fun!

 

[amg_meister]

ehhhhh...ish. Head bolts are entirely hit of miss. I know of 07's with over 150k on original bolts. I know of Late/plastic valve cover engines popping before 75K.

You mean head bolts popping on the late engines or another issue?

The only issue that was ever 'remedied' was the head bolts after engine number 60658. Cam adjusters, cam wear, etc is all the same up to 2015.

 

[jhodg5ck]

You mean head bolts popping on the late engines or another issue?

The only issue that was ever 'remedied' was the head bolts after engine number 60658. Cam adjusters, cam wear, etc is all the same up to 2015.

bolts popping, so I don't jive on that whole remedy things But again, I think the problem as a Whole is over wrought on the interwebs

 

[amg_meister]

bolts popping, so I don't jive on that whole remedy things But again, I think the problem as a Whole is over wrought on the interwebs

Yeah, all from that R63 Grassroots Motorsports forum post - a perfect storm that spread all over the internet. Meanwhile, Tasos Moschatos is putting out videos of countless M157s with bent connecting rods and scored cylinder walls.

 

[gsxr]

Meanwhile, Tasos Moschatos is putting out videos of countless M157s with bent connecting rods and scored cylinder walls.

I'd sure like to know the root cause of the M278 and M157 failures, which seem way worse than the silly M156 bolt thing.

 

[duuder]

Yeah, all from that R63 Grassroots Motorsports forum post - a perfect storm that spread all over the internet. Meanwhile, Tasos Moschatos is putting out videos of countless M157s with bent connecting rods and scored cylinder walls.

can you forward the post from grassroots?

 

[amg_meister]

can you forward the post from grassroots?

R63 AMG The Unicorn of my Destruction

R63 AMG The Unicorn of my Destruction

grassrootsmotorsports.com

 

[duuder]

R63 AMG The Unicorn of my Destruction

R63 AMG The Unicorn of my Destruction

grassrootsmotorsports.com

thanks, i found the thread but didnt know where to start. this the most reasonable why to approach it. lost interest after page 15

 

[gsxr]

Page 15? Only 114 pages left to go!

Spoilers... there's a startup video on page 86. Some cool photos throughout if you just look at the pictures.