strangebrew

First post here. Just got my car back from getting some dash/instrument cluster rattles cured and I already have another complaint.

I noticed that my 2012 C250 sedan (>3000 miles) is making noise somewhere in the rear suspension. I can hear it when I have my windows down and drive over basically any bump (even small ones) at speeds from 10-40 mph. It sounds like metal plates gently clanging together. It's not a popping or grinding noise and not particularly startling, but I don't think I should be able to hear my suspension as I'm rolling down the road. It kind of reminds me of the sound that driving over a small, loose manhole cover makes.

Am I crazy? Any ideas before I take it in to the dealer?

Carsy

Can you replicate it by excercising the rear shocks when the car is at a standstill ?.

Give the muffler a tug around to see if it the cause .

Let us know how you go with the dealer.

strangebrew

Thanks for the suggestion. You know, since it's on the driver side of the car maybe it is the muffler or exhaust. I haven't tried messing with it yet at a standstill.

I am taking it in on Wednesday and will update.

strangebrew

So they told me my parking brake was loose and causing the noise. Got the car back and it's still making the noise. Sounds like Im driving a damn flatbed, not a $41k car... back to the shop again...

mfkl2

Ive had same problem. Took it to the dealer 8 seperate times and finally they fixed it. You gotta keep bothering them about it.

kevink2

1) Find a place near the dealer where you can easily replicate the noise

2) Take the tech to the spot and let him hear it (note speed and gear) when you bring the car in.

3) Ask the tech to do the test drive when he thinks it's fixed, before you go back to pick up the car.

.

ralawren

I had a similar issue in our 2011 C300 Sport 4Matic. But it was a noise that sounding like a groan or rubber rubbing. We only hear it at slower speeds when the suspension extends and contracts.
The dealer found a service bulletin and replaced a part in the suspension and did a 4 wheel alignment. It didn't help but I got a free alignment out of it.

strangebrew

It's been fixed! I took two mechanics on a drive with me and they confirmed it was coming from the parking brake. They ended up basically reassembling the whole thing and swapping out the springs and pins in the assembly. I also had them recalibrate my hold assist because it was noisy and grabby every time I switched into reverse or drove off from a stop light. Back to happy driving!