'19 c63s sedan only 300 miles..
When accelerating at a regular speed from a dead stop I hear this odd knocking sound for a second coming from the front of the car. It's right as the car starts to accelerate. If I go over speed bump and my cars sways side to side I hear it as well. Any ideas?

 

I get some strange rattles in park, neutral.. as if the turbos are fluttering,, maybe not but some kind of f clatter as I step on the gas and after release as the idle settles. Something is rattling and I cannot figure out what it is. I have the same engine my g550 but it doesn’t rattle at idle like this. In drive I do t hear it, only when it’s idle in park

 

I have that exact same issue with my 19 sedan. Hoping someone knows what it may be!

 

Can you record the sound? I have a '19 sedan and have not heard anything out of the ordinary.

Also the swaying does not sound normal.

 

19 coupe here, 2k miles.
I hear a very faint pop if the car has been sitting for a couple days when I first pull away but I think its just the brakes releasing.
Nothing else unusual at all.

 

I'll try to do a recording soon. It's like a knocking sound when the car shifts position aka accelerate. Something in the engine bay shifting ?. Maybe the plastic cover..

 

When you look around in and under these vehicles, you can see that there are a huge number of multi-layered parts consisting of metal heat shields and/or plastic panels that are layered onto the unibody and sometimes onto each other (unibody, heat shield, plastic shield), especially underneath the vehicle. In addition, you have various plastic fenders, skirts 'n aero-parts joined to each other.

All that creates a huge number of places where things can vibrate under various conditions and resonant frequencies. And this is not to mention all the plastic-on-plastic and plastic-on-wood/metal adjacencies in the cabin.

While buzzes 'n squeaks 'n rattles are annoying, given the construction of these vehicles, I sort of expect a bit of this and am willing to accept some level of noises, as long as they're not during normal, relatively smooth-road driving. Under strong acceleration or driving over very rough roads, I find both my C43 and C63 S will offer up some noises -- some, like the exhaust sound are wonderful, others "no so much."