204Racer

Hi, I have just bought a W220 S350 (3.7L M112) about a month ago. This is my first S class and my first ownership of a car with pneumatic suspension.

I have a problem with the suspension (Airmatic w/o 4Matic) and really hope that more experienced members here can shed some light on my problem, as follow:

1) When I drive slowly (normal slow) perpendicularly over a speed bump, I feel the car 'wiggles' at the front and the rear as the suspension rebounds, while producing a muffled thump both at front and rear (I can feel with my feet on the floor when both ends thumps).
2) When I drive over the same speed bump at higher speed (say like you are in a rush and has no time to really slow down), the symptom go away.
3) At freeway speeds there is nothing to indicate anything wrong with the suspension.
4) No trouble codes appear on the car's screen, and none also came up on the workshop's diagnostic computer.
5) I can still raise the suspension normally with the button ('Airmatic Rising' message came on about 25-30 seconds).
6) I can still feel the difference in stiffness when I select Sport 1 (firmer) and Sport 2 (really stiff).
7) In Sport 1, the same symptom still felt over speed bumps.
8) In Sport 2, the symptom completely disappear.


To note, the front suspension has some ball joint(s) wear.

My regular workshop said that this is a symptom of the Airmatic bags are going bad (minute leak). However, if this was the case, wouldn't going to Sport 1 & 2 will result in same symptom? Or is this more mechanical (like bushings or balljoints)?

I don't mind replacing the struts if need be. But I don't want to replace it unnecessarily.

Any advice and guidance is very appreciated.

Many thanks,
Renaldi

lganski

Since you did not tell us the year of the car if it's older you may have an issue with your ball joints. Have them checked for wear.

ImInPA

What you describe does not sound like anything is wrong. When hitting the speed bumps faster, you are taking advantage of the additional damping provided by the airmatic system. It would certainly not hurt to have the ball joints inspected for wear. If there is no wear detected, turn up the stereo a notch or two when slowly going over speed bumps.

204Racer

Many thanks for the advise. Yes, there is a problem with the balljoints. I will handle this first before replacing the struts.

ibeforreal

Ball joints.

204Racer

Hi all, just want to give an update on this problem.

I had the balljoints checked and they are fine. It seemed the air springs (bags) are also fine but the shocks had some play at the last few inches of travel. So i replaced them with Arnott's coil spring kit and the problem thankfully went away.

Thanks all.

corkshoppe

ball joints, a huge problem with s class,