I’m struggling to resolve an issue with my 2016 SL. The engine seems to be vibrating excessively at speed (say 60 or so) and accelerating. It’s only felt when power is applied. From reading I was thinking it was motor mounts and have replaced the front and rear mounts (admittedly not with OEM parts).

Doing the break test the engine does not move up more than an inch or so and seems to be correct. What I don’t know is if the mount is working properly at high RPMs. I believe I read they should stiffen and this is facilitated by the vacuum hose coming from both mounts.

Are there other possible issues for this? Is it possible (or likely) the replacement parts just aren’t quality and if so, any recommended replacements? If one of the hoses is damaged would that be a possible answer?

Thanks!

 

What makes you believe it is the engine that is vibrating?

 

It only occurs when I give power. It definitely doesn’t “feel” like something small(er), The engine cover V6 appears to be worn or wearing.

I’m also 1000% sure I’m clueless as to what else it might be.

 

Is there vibration when you give power while in park or neutral?

 

No vibrations in park or neutral with power. Attached is a video of break test in drive and reverse.

 

This is sounding suspiciously like it may be related to your transmission. Your CVT transmission is connected directly to your engine so any problems with the CVT will be transmitted through the engine. It makes sense then that if it is the cvt, that would be happening under load, and obviously while the transmission is in drive. Please report back on your findings.

 

Is vibration the only symptom we would see from a failing CVT and how could we get that diagnosed with any integrity? We don’t feel any other slips or misses or lagging power / acceleration issues at all. Is that relevant?

 

Could also be a CV axel going bad.

 

Is the CV axle something that would could diagnose visually? Any thoughts on how to further diagnose this (including the CVT itself) and can we rule out motor mounts at this point?

 

The five telltale signs a CV axle is going bad.
1. Clicking sounds when turning left and right
2. Clunking sounds when turning and going in reverse
3. Engine vibrations when accelerating
4. Torn CV axle boot
5. Excess play in axle when wheel lifted off the ground.