PLEASE HELP c300 Rotational Grind Noise front end
Thread Starter
Junior Member
Joined: Jul 2020
Posts: 16
Likes: 0
2015 c300 4matic
PLEASE HELP c300 Rotational Grind Noise front end
Anyone know what this is? Brakes and everyrhingbhave been checked by MB dealership. They said it was tire bead flexing on rim so the dismounted, sealed and remounted tire. The noise remains.
https://youtu.be/yM9QUYDBIc0
https://youtu.be/yM9QUYDBIc0
Senior Member
Joined: Jun 2015
Posts: 256
Likes: 26
From: Dutchess County, NY
2016 C300 4matic
I have the same exact issue with mine. 2016 with ~74,000 miles now. My plan is to replace my brake rotors this weekend or next so i'll take it apart and let you know what I find. My personal guess is that it's my rotor since i've never replaced them for the life of the car, but I won't be sure until I get everything apart. I've replaced the pads once at around 25-30,000 miles with ceramic pads but I don't believe they are the issue. It very well could be a stone or foreign object trapped in there but my thoughts are that it would have popped out by now because i've had this for a while and since it started i've also swapped my summer/winter rims once and didn't see anything obvious.
Senior Member
Joined: Jun 2015
Posts: 256
Likes: 26
From: Dutchess County, NY
2016 C300 4matic
So I took the wheel and caliper off and took a good look at everything. I have a slight lip on the front of the rotor, but nothing unexpected. What I did see was two things that tell me it's time to replace the rotor...
1. The back of the rotor has somewhat excessive circular etching, which is not visible on the front
2. The rear pad in the caliper has the normal circular wear marks but there are jagged etchings about 90 degrees to the pad and you can put your fingernail in there so it has some depth.
My pads are ceramic, replaced around 20k miles and the rotors are original (77k miles now). The pads are barely worn but i'm confident i've outlived the life of the rotors. I'll order some this week and replace them next weekend and report back.
1. The back of the rotor has somewhat excessive circular etching, which is not visible on the front
2. The rear pad in the caliper has the normal circular wear marks but there are jagged etchings about 90 degrees to the pad and you can put your fingernail in there so it has some depth.
My pads are ceramic, replaced around 20k miles and the rotors are original (77k miles now). The pads are barely worn but i'm confident i've outlived the life of the rotors. I'll order some this week and replace them next weekend and report back.
Thread Starter
Junior Member
Joined: Jul 2020
Posts: 16
Likes: 0
2015 c300 4matic
So I took the wheel and caliper off and took a good look at everything. I have a slight lip on the front of the rotor, but nothing unexpected. What I did see was two things that tell me it's time to replace the rotor...
1. The back of the rotor has somewhat excessive circular etching, which is not visible on the front
2. The rear pad in the caliper has the normal circular wear marks but there are jagged etchings about 90 degrees to the pad and you can put your fingernail in there so it has some depth.
My pads are ceramic, replaced around 20k miles and the rotors are original (77k miles now). The pads are barely worn but i'm confident i've outlived the life of the rotors. I'll order some this week and replace them next weekend and report back.
1. The back of the rotor has somewhat excessive circular etching, which is not visible on the front
2. The rear pad in the caliper has the normal circular wear marks but there are jagged etchings about 90 degrees to the pad and you can put your fingernail in there so it has some depth.
My pads are ceramic, replaced around 20k miles and the rotors are original (77k miles now). The pads are barely worn but i'm confident i've outlived the life of the rotors. I'll order some this week and replace them next weekend and report back.
Trending Topics
MB World Stories
The Best of Mercedes & AMG
Manual Mercedes? 6 Times Sindelfingen Let Drivers Have All The Fun
Verdad Gallardo
Mercedes SLR McLaren 722 S Is Extremely Rare Example Modified by McLaren
Verdad Gallardo
8 Classic Boxy Mercedes Designs That Have Aged Like Fine Wine
Verdad Gallardo
Flawlessly Restored Mercedes 190E Evo II Heads to Auction
Verdad Gallardo
Electric Mercedes C-Class Unveiled: 11 Things You Need to Know
Verdad Gallardo
Mercedes EQS Gets A Major Update: Everything You Need to Know
Verdad Gallardo
5 Underrated Mercedes-Benz Models That Don't Get the Love They Deserve
Verdad Gallardo
Mercedes 300D Has Pushed Well Past 1 Million Miles and It Ain't Stopping
Verdad Gallardo
10 Most Reliable Mercedes-Benz Models You Can Buy Used
Verdad Gallardo
Thread Starter
Junior Member
Joined: Jul 2020
Posts: 16
Likes: 0
2015 c300 4matic
It sounds like a broken belt in the tire. Could also be runflat low on pressure:
https://youtu.be/2C1jUzummrQ
https://youtu.be/2C1jUzummrQ
Thread Starter
Junior Member
Joined: Jul 2020
Posts: 16
Likes: 0
2015 c300 4matic
So I took the wheel and caliper off and took a good look at everything. I have a slight lip on the front of the rotor, but nothing unexpected. What I did see was two things that tell me it's time to replace the rotor...
1. The back of the rotor has somewhat excessive circular etching, which is not visible on the front
2. The rear pad in the caliper has the normal circular wear marks but there are jagged etchings about 90 degrees to the pad and you can put your fingernail in there so it has some depth.
My pads are ceramic, replaced around 20k miles and the rotors are original (77k miles now). The pads are barely worn but i'm confident i've outlived the life of the rotors. I'll order some this week and replace them next weekend and report back.
1. The back of the rotor has somewhat excessive circular etching, which is not visible on the front
2. The rear pad in the caliper has the normal circular wear marks but there are jagged etchings about 90 degrees to the pad and you can put your fingernail in there so it has some depth.
My pads are ceramic, replaced around 20k miles and the rotors are original (77k miles now). The pads are barely worn but i'm confident i've outlived the life of the rotors. I'll order some this week and replace them next weekend and report back.
Senior Member
Joined: Jun 2015
Posts: 256
Likes: 26
From: Dutchess County, NY
2016 C300 4matic
I replaced both my front rotors last weekend and the issue is gone. I can't say for certain your problem is the exact same issue but for me it was night and day difference. I have to get my front drivers side tire replaced next week. I'll see if they notice anything when they do it.
