- Mercedes-Benz C-Class AMG: Common Problems
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Common suspension noises and solutions
Does it happen anytime you brake? From any speed? Or do you have to brake with a minimum amount of effort in order to feel it? Is it when the body of the car pitches downward when you brake hard enough?
* If it's a creak, then look at the front or rear sway bar bushings.
* If it's a clunk or clatter when driving over a pothole, bumps or irregularities in the road, look at the sway bar end links
* If it's one or more distant "knocks" when braking hard, look at the control arm bushings.
* If it's a creaking only while turning the steering wheel, look at the top strut mount
* If the car steering "slops" to one side or the other depending on the crown of the road, look at the steering rack bushings.
* If it's a knocking or loose joint sound when you back out of a driveway or hit small bumps at low speeds, look at the inner or outer tie rods, or play within the steering rack (this is what I am still chasing down).
You have the same car I do (2005 c230 w/ sport suspension), so your front sway bar bushings are likely shot if you haven't replaced them yet. The replacement is a new sway bar with molded on bushings ... evidently they had so much of a problem with noise from these bushings that they molded them onto the bar. I haven't replaced anything in the rear of the car yet.
I'll probably just lube them so the noise goes away then turn the car in in the Summer for something else.
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Have you discovered what your noise come from yet? The knocking noise while backing out of the driveway. From my experience the tiers or steering rack bushing doesn't make a knocking noise. What you can do is have someone turn the steering wheel back and forth and you can see if the steering have any play in it, if not then it is neither the tired nor the rack bushing...
The bushes at the BASE of the shock are worn out and need replacing.
However, replacing them means new shocks as the bushes cant be replaced.
As my car is not fitted with the self levelling system, it should be about $400 for parts.
How long have you had your car for, John?
Ben, these must be for the rear, yes?
Fyi,
* the rears are monotube, and the same shock is used for both sport and non-sport suspensions.
* The fronts are twin-tube, and I didn't know it but there are different struts for sport vs non-sport -- strut length is 3/4" less for sport, plus the sway bar link hole is M12 vs M10, plus the sport damping is slightly less (yes less) than for non-sport. Since i could only find one type of strut I ended up getting the one for non-sport, drilling out the sway bar link hole, and I live with extra 3/4" suspension travel whenever I jack up the car. The car handles very well, and I don't know if I would be able to tell the difference between the sport and non-sport damping rates (presumably the lower damping rate on the sport might reduce resonance on wavering roads at certain driving speeds ... who knows.)
But the car does feel sportier than it did with the stock suspension.
Last edited by jkowtko; Mar 3, 2016 at 04:21 PM.
I really don't feel like changing the sway bar, I think it's about the time and mileage when a lot of parts will need changing (i'm still on original water pump and starter). I'm seriously considering the 2017 E-class when it comes out but until then I'm going to need to keep this car on the road as it's fantastic on gas and nimble to drive.
Replaced in the front:
Sway bar
Sway bar bushings
Sway bar end links
Balanced all tires.
Driving straight and at all different speeds it's audible. No vibration in the wheel, just a constant wawawawa type of sound, all brakes and rotors have been replaced as well.
Front bearings possibly?
I had General UHP Exclaim tires on my car during it's middle years, and at one point I thought I needed a new front suspension, transmission, and differential, there were so many whining, grinding and vibrating sounds. I decided to replace the tires first, and it pretty much all cleared up
In the old days if you have front wheel drive cars and don't rotate the tires the rear will cup really bad and make noise just like a bad wheel bearing.
BTW all my front end noise is gone now, what I did was loosen the sway bar and greased all around the rubber bushing where it contact the frame and the bracket.
I must say, after replacing, the car is significantly smoother over bumpy driving conditions. As you can see below, the Front-Upper bushings were shot!

If you haven't replaced the engine/tranny mounts yet and you can hear any engine noise/vibration, time to do the mounts. This will result in another noticable improvement in ride noise/quality.
-- John
I replaced the tranny mount last winter, so that's checked off the list. I'll need to do the engine mounts after winter; remarkably they're holding up well for 12 years, no issues. Yet...








