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So I'm currently almost at my wit's end trying to fix and diagnose a suspension noise on my C200 Kompressor wagon which has done about 155K km. I've changed the sway bar drop links, engine mounts, the trans mount and both front thrust and control arms as they all seemed worn and could have contributed to the noise.
This has cured a lot of "slop" in the suspension and drivetrain so the car feels like new when driving it again which is great.
However, it still hasn't cured the dull rattling/thudding noise when driving down the road at 50-60km/h and there's also some noise when I stop and take off from under the car. Another weird symptom is that the noise gets worse as I drive the car more, I guess as something is heating up its getting worse? I can feel some small vibrations through the steering wheel when the noise is happening too.
I'll try and get a video of the noise so its easier to diagnose but from these symptoms does anyone have any idea what could be causing the noise/vibration? I've heard perhaps its the shock mount bearings but is there any way to actually verify this without taking the whole shock assembly apart? There isn't any noise when the steering rack is going lock to lock.
- Dull rattling/thudding noise at 50-60km. Gets worse while driving. Can feel it through the steering wheel.
- Some noise from under the car upon stop and go.
Is it RWD or AWD? Could be the wheel bearings, that would transfer to the steering wheel and coincide with vehicle speed. Im thinking if it were the struts the sound would happen more when turning.
- Dull rattling/thudding noise at 50-60km. Gets worse while driving. Can feel it through the steering wheel.
- Some noise from under the car upon stop and go.
Is it RWD or AWD? Could be the wheel bearings, that would transfer to the steering wheel and coincide with vehicle speed. Im thinking if it were the struts the sound would happen more when turning.
Its RWD. I've had a wheel bearing fail before and the symptoms were different. There's no whine or bearing noise even at highway speeds at the moment. It definitely sounds like something is knocking on something but it doesn't sound like metal on metal either...
Its RWD. I've had a wheel bearing fail before and the symptoms were different. There's no whine or bearing noise even at highway speeds at the moment. It definitely sounds like something is knocking on something but it doesn't sound like metal on metal either...
What about the flex discs on the front and rear of the driveshaft or the center support bearing? These are all underneath the vehicle and can cause the dull thudding noise you described when worn or damaged.
I was researching symptoms of worn strut bearings and seems vibrations will be one. Could be causing the wheels to wobble.
Jack up the front end so the wheels are off the ground and push on the top of the wheels back and forth trying to see if the top of the strut mounts have any play. May take alot of force since the springs are compressed up in there. This could also be related to the noise you hear stopping and starting.
I'll give that a go next time. I'm thinking though more and more that its possibly the anti roll bar bushes. Merc doesn't sell the bushes separately so where's a good place to source these from?
I'll give that a go next time. I'm thinking though more and more that its possibly the anti roll bar bushes. Merc doesn't sell the bushes separately so where's a good place to source these from?
I dont think the sway bar bushings are replaceable, they are formed and stuck to the bar and instead a new sway bar would be needed. I don't think worn bushings would cause a constant vibration, it would probably be a metal on metal clunking noise when going over bumps but I could be wrong. Mine have some visible cracks in the bushings and I just spray them down with silicone spray lubricant every so often to prevent squeaking. I think theres 2 or 3 different sway bar models, a RWD, AWD, and Sport.
You can always remove the sway bar links and drive around and see if the noise goes away.
¿Es este tu ruido? [/CITA] This noise comes out after 5 or 10 minutes of driving, even on the highway or highway. I couldn't find the origin, everything changed recently, it started shortly after changing parts. They were the shock absorber-stabilizer bar links, the manufacturer's tightening torque was not enough. My brain exploded when I found it. If it seems a little retighten those 4 nuts
That sounds so much like a bad center support bearing. The rubber membrane between the bearing and the mount tears, allowing the driveshaft to move up & down and side to side as it rotates. It then hits against the bearing mount, causing a sound similar to the video.
https://youtube.com/shorts/BGJTo62AnnE?feature=shared ¿Es este tu ruido? [/CITA] This noise comes out after 5 or 10 minutes of driving, even on the highway or highway. I couldn't find the origin, everything changed recently, it started shortly after changing parts. They were the shock absorber-stabilizer bar links, the manufacturer's tightening torque was not enough. My brain exploded when I found it. If it seems a little retighten those 4 nuts
This might be the issue, I did install the links myself recently but perhaps I didn't tighten enough. I saw recently in a video that its meant to be 98Nm which is actually very tight
The larger M12 nuts and bolts im finding are all around that torque spec, or if theres a bushing it can be something like 50nm + 90 degrees. Control arms, sway bar links, brake caliper brackets etc. I've seen people say they have trouble torquing the sway bar links but I found after the nut is on snug just use the torque wrench and socket right on the nut and it will tighten.
Guess it depends on what tool your using if it feels tight or not. If your using a 3/8" drive ratchet then sure its very tight, but use a 1/2" drive breaker bar and its snug.
Ok here's a recording I made tonight, you do have to turn the volume up. Its rather faint but you can definitely hear it. More noticeable as I'm coming to a stop at the red light and below 40km/h
It doesn't seem like it's from the powertrain, it doesn't disappear when braking or accelerating, it's still there. stabilizers or maybe something unscrewed there?
It doesn't seem like it's from the powertrain, it doesn't disappear when braking or accelerating, it's still there. stabilizers or maybe something unscrewed there?
That's what I am thinking also, have checked and refitted both stabiliser links over the weekend and made sure they were torqued up. The left hand one though was still making a bit of a clunk after I tightened it up and when I tried to wiggle it by hand but I had to put quite a bit of force into it for it to make any noise. Right hand no noise at all. Maybe its the stabiliser/anti roll bar bushes or brackets? Or maybe I've got a dodgy new stabiliser link?
What brand links are installed, Mercedes or an aftermarket brand? I recently posted my experience with aftermarket front sway bar links, how the chinese clones are junk. With the chinese ones the collar on the threaded part seem to be made of two pieces, the Mercedes and the Febi links I used look to be machined from one piece.
Here you can see the chinese link the collar looks pressed on. Not machine from one piece.
Heres what happened when I tried to tighten them down, looks like the collar part was pushed in. This resulted in a loud clunking noise.
I purchased Lemforder ones from FCP, but I did notice that the collar and the thread were separate. The collar is basically like a washer and pushes up against a groove just in front of the rubber boot. Can't see your images above but I'm assuming that's what you mean and could be causing the noise.
Is it possible that I may have installed these incorrectly? I checked and the right hand side one has an R on it so I think I've got them on the correct sides of the car.
Installation is pretty straight forward. I did notice when I only jacked up one side to put them on the holes werent lined up, seems the side on the ground was putting pressure on the sway bar. So I jacked up the entire front end and everything went into place much easier.
That is what I am planning on doing next and it'll give me a chance to check the stabiliser bar bushes with the links disconnected. It does seem consistent with worn bushes from my experience with other cars
I purchased Lemforder ones from FCP, but I did notice that the collar and the thread were separate. The collar is basically like a washer and pushes up against a groove just in front of the rubber boot. Can't see your images above but I'm assuming that's what you mean and could be causing the noise.
Is it possible that I may have installed these incorrectly? I checked and the right hand side one has an R on it so I think I've got them on the correct sides of the car.
That is the exact model with which I had the problem in the video. I installed it and two months later the noise appeared. I didn't think about the links I had just acquired.
01-27-2024, 04:25 PM
