Ultimate Clunking Mystery Extravaganza - 12th Anniversary Edition!

tchalikias

Paid Member
I recently opened another thread regarding a new grinding/rubbing noise from the front left on my 2010 200, and since I'm gonna be taking care of it, as I did a few other things lately after a few years of not really dealing with car-related issues, I figure that perhaps, a decade later, I can maybe also get to the bottom of my 200's enduring and unfathomable feature: the mysterious clunk from both left and right sides, at the front.

This started about a couple of months into ownership (bought new), and has been looked at by at least 4 or 5 dealers and independent shops since, and they've all come up empty handed.

While the car was still in warranty, a lot of suspension-related things were replaced. Quite a few more were replaced with wear and tear in the following decade.. but the clunk.. it has never gone away.

This is a clunk I've become so familiar with, that I can almost with 100% certainty know when its gonna be heard, and when its not. Some potholes and road anomalies trigger it, others don't.

I can even describe, after a decade of living with it, what it feels like.. picture in your mind's eye two thin and long strips of metal whose ends are pressed against each other, forming a sort of spring, as they mutually bend, one upwards, the other downards. At some point, due to the bend, their ends slip away and boing the metal strips go. That's what it feels like. You can feel it in the steering wheel, and sometimes in the wheel well, if you're attuned to it. It's definitely an elastic type of clunk.

Its definitely affected by the weather and climate. I think its worse when its hot outside (i.e. summer) and when you pressure wash the underside of the car, or you drive in the rain, it seems to go away for a bit.

A list of things that have been replaced in the quest to eliminate this noise or due to wear & tear, with the noise staying the same:

-both shocks
-both shock top mounts
-steering rack & tie rod ends
-anti-roll bar links
-lower ball joints on the carrier hub
-all four engine mounts

By my estimation, the only things left that could be knocking are the anti-rotation link bars, the anti-roll bar and the lower wishbone with its joints.

The weird thing is.. this started at around ~ 1000-1500 km and has been pretty much the same 85,000kms and 12 years later. I find it hard to believe that its something worn.. but then, to be heard distinctly on both left and right sides? It must have been either a faulty batch of identical left and right side parts, or something that runs the width of the car (like the anti-roll bar, and its mounts).

I really, really like this car. Its starting to show its age lately, with things not working exactly as they should (knackered cruise control, leaking A/C radiator, dead thermostat, grinding noises, but I wanna stick with it cause I love driving it so much, despite the unnecessary noises.

So, time to place place your bets gentlemen. What do YOU think is the origin of this mysterious clunk?