MPTrader

I have searched the W212 section for the WIS and information on the removal and replacement of the M276.9 (non 4Matic) motor/engine mounts. I replaced the transmission mount this past Saturday and figure I would investigate the engine motor mounts next. All I find are the 272, 273 or 4Matic versions. I would appreciate some help here - even a point toward a thread if I missed it. Thanks

MB4429

What’s the VIN for the car? I can provide you the WIS documents if you need.

MPTrader

Thanks for the help... I ordered an online manual and will wait for that since I was not planning to do the mounts right away. If the manual does not work well I will let you know. Again thank you - much appreciated.

MB4429

Of course! I did my mounts this past summer and the car rode sooo much better.

Rickman30

OEM Part and number, link below

Corteco Engine Mount | 2042404317

https://www.autohausaz.com/pn/CC-2042404317

Of course you can get others that fit fine, but this is the manufacture of the mounts for MB.

ChrisHimself

It's done entirely from the bottom of the car. You'l have more room than the V8 an ESPECIALLY the 4matic V8 models. It's like an hour. I have no idea how it's $1500 to do the three mounts but if it pays that much, I'm taking it. You can get around the exhaust or remove it completely IIRC. I'm mainly doing it on AMG's so I just remove the exhaust all the time always.

You can use the meme wrench but I honestly have never ever used one despite owning like 3 of them. I use a box end flex head ratcheting wrench.

S-Prihadi

Yep exhaust system need to be removed, all of them as easiet and fastest. While at it, buy new exhaust bolts 2 + 2, as they rust alot from heat.
I done at my indie, twice engine mounts + tranny mount replacement and I have a turbocharger being a M276.820 3.0TT.
My fat hand can not reach the lambda sensors interconnect connector, otherwise I will DIY it.
If non turbo M276 3.5NA, I think easier for that lambda sensor interconnect connector.

MPTrader

That's great. Looks like you have the same year and model as mine - I have a 2014 E350 RWD too. Any good tips or did you do a write-up or refer to a good DIY video?

MPTrader

Is the meme wrench that small angled one that I have seen that someone made?

ChrisHimself

it would legitimately take longer for me to explain it in video form than it would for you to just look at it from the bottom and get to it. all the write-ups and videos of the past neither explained whats actually under there nor did it show proof of the work being done.

there is a main bolt holding the engine to the car, but its under a heat shield so you can't actually see it from the top so people misunderstand what the engine mounts actually are. there is a long bolt protruding from up top holding the engine to the mount through to the subframe and two smaller anchoring fasteners from the bottom to the subframe. you're going to reach over the top of the mount and attach your box end and loosen it. it's not held on with a ton of torque so don't overthink it but a conventional wrench is the important tool here since you can't fit a socket. you only need to remove the exhaust midpipe and therefore the O2 sensor for the left one IIRC and again I recall the v6 ones being possible without this technique vaguely but I have never done it this way. I work on hot cars and so do 90% of people so I just remove the exhaust for MOST jobs, so replacing the flex discs, carrier, trans mount, and engine mounts at the same time makes it so you never have to do this again

in my experience they got the rubber compound right on the W212's because the flex discs seem to last for a lot longer than the 90's cars

no its the 17-18mm wrench attachments that let you hit it from an offset angle but i have never found these necessary

MPTrader

@ChrisHimself Thank you for this information and all the detail. I will remember this too as it is very true => "......than it would for you to just look at it from the bottom and get to it"

S-Prihadi

Here is what I hate most for engine mount replacement, that lambda sensor and oxygen sensor, 2 interconnect connector per side.
Its high up and hidden for my engine. My Indie staff is skinny and long skinny hand so he can do it easy.




.




Its actually at the bell housing near the very top, side way a bit like 10 and 2 o'clock, that interconnect connector.




I was replacing all 4 lambda/oxyhen sensor for photo below. At my indie.




Before they break, these bolts best to be replaced. Often the broken part is stuck at the female thread inside, the flange



Stay safe under the car.