I’ve seen the threads about how to change motor mounts, but I haven’t seen a thread on why and when you need to do it? I have a 2014 E63S, and it has some vibration at speed. I had wheels balanced and alignment, which got rid of a 70 MPH vibration (which I believe was wheel balance issue), but now the car tracks straight and true, just has a very minor vibration, which actually feels to me like road surface translating through the seat and wheel. But maybe there are other symptoms?

What I’d really like to do is to drive someone else’s to see what it feels like, I know a couple folks who have them here in Atlanta, just haven’t made it happen yet. But maybe these symptoms resonate with someone else?

TIA

Jim

 

check out some videos on how to check your motor mounts. Very easy to determine. First you open the hood so you can see the engine from the driver seat. Next you place car in drive and foot on brake. REALLY KEEP YOUR FOOT ON THE BRAKE. Rev the engine and watch the engine. Does it tilt to one side or jump up? Next place the car in reverse with foot on the brake and rev engine. Does the engine tilt or jump?

Giving the gas pedal a couple blips allows you to watch the engine move if the mounts are bad. You may also hear a clunk or feel it when the motor mount reaches its extent of travel more speedily because there is not dampening power left in the mount. The mounts are fluid filled but it’s often hard to see them leak under the mount cover.

 

I had a faint vibration around similar speeds on my 15 63 . Ended up being both of the rubber driveshaft flex discs , really smoothed it out . How many miles are on it ? my discs were orinigal @ 95k and were pretty cracked.

 

Mine is a 2010 with an M156, different engine but same issues. When my mounts went out there was noticeable vibration at idle. Worse when the car was in reverse. I’m also in Atlanta - had them changed by a local Indy shop I trust. They were shot.

 

Cars got 66K on it. I feel like I need someone who really knows these cars to look at it, don't want to start replacing stuff ***** nilly. But will keep that in mind

 

The car is vibration-free at idle, which is one reason I dont <think> its motor mounts. Frankly, I'm not sure it isn't normal... It's that subtle.

 

Did you do the very simple universal test that I suggested?

I learned this test 30 years ago and it is still the standard and best test.

This test allowed me to determine that my mounts were shot at just under 60k miles on my '13. The techs at MB were even unsure until they reinspected at my insistence and found the mounts were dead. (many think vibrations are normal, but only certain vibrations are and drivers know best)

If you have not done this test, there is no better advice anyone can give you here. There are tons of places to look for vibrations but only one way to test mounts.

Let us know how it goes and if you are unsure, post a video. It takes less than thirty seconds to complete.

 

The mounts on my 2013 E350 mounts died ~2019-'20 with ~70k on it. My 2016 mounts with 60k died a few months ago. The '13 had a lot of vibration, the '16 I can barely tell. Seems to me theyre engineered to just make it past warranty.
So if they are the orig mounts I'd say theyre toast. Even if not, they will die very soon. I bought aftermarket urethane mounts because they will not fail again, and basically the same price, but have yet to install them because I dread doing it.