stoneycreek

Hello friends.
I have a 2015 S550L 4matic with 66.000 miles. I have been chasing this subtle thumping or clunking noise for months now. I have been under the car many times, could not see anything out of the ordinary. I have even replaced sway bar links and that did not make a difference. It is mostly steady and consistent on uneven or bumpy road. I do not have any suspension issues, no leaks, car does not pull to the side, except for this thump sounds. When the car is parked and if I turn the wheel side to side to rock it, no noise or thumping. I have attached the video link here,THUMPING NOISE, please ignore the cabin noise and listen to the constant thump as I sway the car left and right in the parking lot. This thump is always the same and at the city speeds. I did not notice it on the highway. I will disconnect the sway bar to eliminate the sway bar assembly and see if it thumps than. What I have seen in my search trough the innerwebs, people have either replaced passenger shock absorber or sway bar link components. If it is the shocks, what's the best place to get them, meaning reliable and cost effective? Thanks and your opinions are appreciated.

vinflouen

Usually that is control arms. Probably the lower ones.
Check the rubber bushings for wear or cracks.

ChrisHimself

Sway bar links, they can go out every 50k if you're hard on the car or hit bumps at an angle quite often. The rest of the suspension is fine.

They're a spherical ball in a plastic cup, they're cheap enough and you can just use simple hand tools to install.

stoneycreek

I have removed the sway bar from the car, took the car for a spin and noise is gone. I took it to work today as well, no thump or noise. Sway bar links I have replaced 5 months ago, I don't think they are gone. I have ordered sway bar bushings. Since sway bar bushings are part of the sway bar, fused together, I had to order an aftermarket bushings from China .

Sactownmb

At 66k possible engine or transmission mounts ??

stoneycreek

Regarding Engine mounts : Good point and I heard engine mounts are a nightmare to replace. Also when they are gone its noticeable as a constant shake when engine is running, starting and shutting off. I don't get any of that.

stoneycreek

Good point and I heard engine mounts are a nightmare to replace. Also when they are gone its noticeable as a constant shake when engine is running, starting or shutting off. I don't get any of that.

waterzap99

The full sway bar is only $160 OEM from Mercedes

stoneycreek

I have seen them on line for $360. Interesting and thank you. I am calling the dealer right now

waterzap99

I was looking at this one. Might be the wrong one, but cant believe it would be much more.

Stabilizer Bar - Mercedes-Benz (222-323-12-65)

• MSRP:$218.00
• Discount:$56.68 (26% off)
• Sale Price:$161.32

S450. Sedan, without 4-matic. S550e. S560e. Sedan, rwd. S600. S65 amg. Cabriolet.

stoneycreek

Just called my dealer here and stabilizer bar or sway bar is $470 Canadian.
Where are you looking at for the above price, yes that is the correct one.

stoneycreek

I found it where you saw it I think, https://www.mercedespartscenter.com/
They don't ship to Canada, at least we are on to something, thank you

waterzap99

mboemparts

ChrisHimself

don't do that I've used those before and they're not a great fit and you get play/creaks over time

the links are probably fine.

Also mounts don't go out at 66k, they can last up to 150k

stoneycreek

not shipping to Canada

stoneycreek

Found Canadian site, thank you, I have contacted them for pickup. $260 CAD, better than $460 from dealer

W205C43PFL

Mind sharing the site for us forum members who are also in Canada?

stoneycreek

Sure thing.
www.mbparts.ca

W205C43PFL

Much appreciated.

stoneycreek

To update. Over the weekend I had a friend come over and help me diagnose the thump in the front end. Work I have done so far: Replaced stabilizer bar links and bushings. Replaced front shocks. Thump still there. Front end is rock solid, no movement anywhere. I have raised the car on the ramps so I can get under it. Had a buddy open the front door and push against the roof line to rock the car to mimic the car motion. And, the thump was there. I went under the car and was able to see and feel where the problem was. Well, brand new stabilizer bar links were *****. Felt the play and knock in both sides, which I could not reproduce with the wheels up in the air. So, burned money on the new shocks, stabilizer bar bushings and stabilizer links. Links I am going to try to warranty and new ones I have ordered from the dealer. Stay tuned for the update tomorrow.

stoneycreek

I have replaced the sway bar links that I have replaced already in April this year. This time I bought them from dealer. Clunk is officially gone. Car drives like brand new again. Thank you all for of your comments.

W205C43PFL

That is good news, now enjoy your vehicle in good health : )

BenzV12

Nice to hear it was solved and I also appreciate your feedback on your issue as well
Happy Driving

waterzap99

Also replaced the sway bar links this weekend. There was a bit of a noise, gone now.
The passenger side bottom side was not totally tight. Not sure if not tightened in factory or just came loose over time.

It was about a three hour job.

Getting them torqued tight was the biggest problem. Have to lift up the suspension with a floor jack and then crawl down in there to tighten things. Not a lot of space.
Of course with a full lift it will be much easier.