Tomislav

Hello guys,
I'm from Germany and searching for a S-Class from 2015-2020 with V8 engine. For the engine I would prefer the S 500 M278, but only with 9G transmission. But the facelift model as S 560 with the M176 has many other advantages, for example better headlights and better comand system.
Also there are very less offers of a good S 500 with 9G.

I worry about the reliability of the M176, because it's an AMG engine. I watched a german video of the M177 where they overhauled the engine at about 150.000km (90k miles). The mechanic said it's 'normal' for this mileage, but it could run some miles more. For me it's not normal to overhaul an engine at 90-150k miles.

Does anyone know if the M176 has a much better reliability than the M177? Because I'm planning to drive the car the next 10-15 years and I'm sure I would reach more than 150k miles.

Here's the video of the M177:
https://youtu.be/-gAnSp-9Y0c?si=BuZb-u15O749kiA7
​​

chassis

M176 and M177 are not significantly different. Early production years had misifiring ignition problems, which were addressed with new ignition coils and ECU programming. Not sure if this was a 100% solution for misfiring.

Lately, there have been reports of leaking rear main crankshaft oil seals (RMS), because the oil-vapor separators have become blocked (failed). This increases pressure inside the crankcase, and the pressure finds the weakest point, which evidently is the rear main crankshaft oil seal.

RMS failures seem to be reported on 63 models: C-, E- and G- mainly.

I do not consider any MB engine to be capable of 150k miles or more, without requiring major repair or replacement. The exception to this is the 3.0/3.5 M276 V6, the most reliable MB engine in the past 20 years.

MBNUT1

This is a good question. Would like to hear from any S560 owners that have high miles. I am thinking that the M176 is a better engine than the M278 only because of the issues identified with the M278 and lack there of with the M176, but that could simply be because the M176's haven't had enought miles on them yet.

Mitch Alsup

Realistically, if you perform maintenance according to the book, you will get a nice long life out of the whole vehicle.
If, instead, you up the maintenance frequency by 25% (10K oil change to 80 OCI) you will add significantly to engine life.

It also maters HOW you drive the car.
Someone who floors the throttle for 5 seconds (0-60) at each stop light will not see as many miles per engine as someone who accelerates similarly with surrounding traffic.

...

Denis Osullivan

[/QUOTE] because the oil-vapor separators have become blocked (failed).[/QUOTE]

Is this a serviceable part?

Donnymac

Precisely.

Tomislav

It would be nice that the newer engine (M176/M177) is better than the older (M278), but I think this is a misbelief. Every generetion of engines has some problems and the new generation has new, other problems. This is very sad, but I think the reason is because they want to build parts as cheap as possible.

I think the M278 is a very good engine since 2015, when the cylinder liners are made of steel.

Of course, it's very important to protect the engine and to adhere the maintenance. But the guy in the video said, that the engine (M177) was driven 'normal'. Anyway it was neccessary to change the pistons and overhaul other parts (at 90k miles).

chassis

because the oil-vapor separators have become blocked (failed).[/QUOTE]

Is this a serviceable part?[/QUOTE]

Yes, at considerable cost and time. Read the E63 threads. The vapor separators are at the front of the engine, buried under and behind other components. Depending on vehicle installation details (intake ducting) the disassembly work to access the separators is either a big job or a really big job. Parts themselves are inexpensive relatively speaking.

juanmor40

https://lifeonfour.co/engine-problem...e-reliability/

Summary from Jul 2023. Similar to comments above.

mercedesbuff

Not sure about the German W222 specs, but in the U.S., there was only one model year with the combination of the M278 and the 9G transmission: 2017.

I have one, and I love it.

Happy Hunting!

Tomislav

Same in Germany, so very difficult to find

Tomislav

I talked to the mechanic from the video. He said the M176 should be more reliable than the M177, because of lower pressures of DI and lower engine power (don't know the correct english designation, but I think you know what I mean )
So far they didn't have a M176 in their shop with any problems, but they have clients with this engine. He said right know they have a S 560 Maybach with 175k miles with no issues but they will have a look at the engine.

MBNUT1

.

MBNUT1

.