Hello Everyone! New to the forums. I recently purchased a 2013 ML350 4Matic. Traditionally a BMW guy, my first Mercedes and love it.

That being said, I recently noticed a metallic like noise when driving over bumps. Car drives completely normal until I hit a bump then it makes the noise (see attached video for the noise). I tried jacking the car up assuming it was sway bar end links. Everything seems to be tight as it should be. Almost sounds like a loose bolt rattling around to me.

Does anyone have any advice on where to look or has experienced something similar? At a loss of where to look next before bringing it to a trust German auto mechanic or MB dealership. Thank you in advance!

 

is this sound coming from the front or the rear? How many miles on it? Maybe it is a bushing that needs replacing.

Where the chrome is on the trunk lid, are you able to push down over and over again to try and isolate where the sound is coming from? If you have a tow hitch maybe you stand on it and slightly jump or lay down and pull it down to you.

I have read that the rear springs can break (scary), have you inspected them for anything significant?

It may also be something loose with a heat shield.

 

Thanks for the response! After doing some more driving, the noise goes away when brakes are applied. This made me look at the brake pads. The inner brake pad on the drivers side is loose and can be moved up and down within the caliper by hand. I'm thinking this may be the cause of the noise. I've jacked the car up and inspected all suspension components and cannot find anything loose, and all bushings appear to be in decent shape for age and mileage. The rear springs were replaced by MB dealership in September. Also, cannot find loose heat shield.

I don't think the brake pad should be able to move freely within the caliper and think this may be causing the noise. Will likely be ordering a new set of pads from FCPEuro and hoping that is the fix!

 

Couple other things to check. If you have off-road package, the big metal plate that covers the bottom of engine has a series of bolts holding it on, make sure they are all tight and not cross threaded (mine came new with 2 that were cross threaded and not tight, and they rattled). Also take your fist and pound on the top of the tire where noise comes from to see if you can reproduce it. Could be suspension on that tire, like the linkage joints. Again, mine had a bad one …top control arm joint…that was bad from factory that caused a rattle.

 

I've listened to your test drive.

The brake pads are a pretty good guess. Before
swapping parts, simply apply light brake pedal to hear if rattle disappears...

Pads can be glued to caliper on inner pad and lubricated on the outer side.

Missing brake hardware springs help relief that.