gabemcclintock

I was able to get a sound bite of the "grinding" noise when the boost is receding. (GoPro inside engine bay)

Noise only happens when the boost gauge recedes just after half. As it recedes, there is kind of a “grinding” noise…almost like fan blades spinning and hitting the surround.
Car was with local MB dealer for over 3 weeks and they acknowledged the noise being abnormal. In that time they told me:

• They replaced drive shaft centre bearing and rubber mount
• They decided to replace turbo charger assembly
• They replaced the front axle propeller shaft assembly

Picked up car this past Friday as I really missed driving it. The noise is still there and now they're thinking it might be something internal of the transmission, or there’s a bearing on the left front half shaft that travels through the oil pan.

Anyone ever hear something like this?

Sound clip here --->

2019 C43 sedan - Boost grinding noise

justinbc43

did you ever find out what it was? I’m getting a sound like that

BHawk

Did you figure out whats causing this?

MaverickC43

There’s some threads on here that I think sound familiar ( just me) I’ve seen people say it’s the waste gate. I’ll see if I can find them
“Bay Area amg”(I’ll look for exact user name)
I think was one of the people giving a fix