sfzach

Recently, my family got a 2013 C350 Coupe with Harmon Kardon sound. Ever since, it has been an ongoing problem that when the bass is set to the higher levels, even on low volume, the rear brake light on the rear shelf behind the backseat rattles against the back window, and creates an awful vibrating noise that ruins the listening experience. When I stuff my hand between the brake light and window, the rattling goes away. Is there anyway I can further the gap between the brake light and window so that they don't rattle, or muffle the rattling?

In addition, certain tones within songs will cause the front seat door speakers to make a very light rattling/vibrating noise. Any idea how to stop this?

This car should have premium sound because of H/K, but these rattling noises make it sound everything but premium.

c204coupe

I have the same issue, when it's cold out no rattles from the bass when it warm/hot rattles for days. I took to the dealer and they added extra insulation under the rear deck, but problem still exists.

CliftonH

I was experiencing the same issue with my C350 coupe and took it to the MB dealership to have it looked at. I thought the rattling sound was coming from a blown tweeter in the window corner, and the dealership replaced it for free (said it was a warranty item). However, when I got it back the rattle was still there. It sounded like a buzzing whenever low frequencies were played.

It was driving me crazy, and having eliminated the tweeter as the cause I started exploring whether any of the interior trim was loose. I discovered that I could make the rattle stop if I took a folded-up piece of paper and wedged it in the crack where the door panel meets the dash. Progress.

After some more effing around with the interior trim, I took off the access panels near the door hinge to see if I could find any loose parts back there. That's where the microcontroller lives that controls the windows/mirror/speakers.



This is the microcontroller

I gave it a bit of a tug and found that it had a little bit of play between it and the mounting bracket. I went and got some weather stripping and stuck it on the back of the microcontroller and put everything back together, and success! No more annoying rattle.



With a bit of weather stripping on the back

Nickanna

Same issue with my 2012. I shoved some extra insulation between the rear deck cover (near the sub) and the deck itself. Has solved my problem for the past 2 years.

Graham Bell

I wish I hadn't read this post.
Now I'll have to go and squeeze my wing mirrors. I did ask the Mrs if she could squeeze my wing mirrors for me. Apparently I should go and squeeze my own wing mirrors, at least that's how I interpreted what she said..