TNJohn

I've poured over the stickies searching for guidance on this issue to no avail. Firstly, my car does not drop or sag over time. That seems to be the majority of posts on the Airmatic. I can park it in the garage for 3 weeks and suspension height will not change, so no air leaks. However, driving down the road and encountering potholes or other imperfections brings out what I consider un-Mercedes-like behavior. There is considerable pitch and yaw, as if each corner has its own idea how to react, and the impacts are harsher than they should be.

Two Mercedes service departments and one independent garage has pronounced the suspension arms, linkages and steering components sound. That leaves something within the Airmatic system amiss. Any ideas would be appreciated.

2006 s500, AMG appearance package, Michelin Pilot Sport performance summer tires, 86,000 miles, owned 3 years

John

tusabes

Airmatic should be smooth confident and stable even at 100+ mph

my w220 with over 200k and worn out ball joints and lca is still stable and smooth

you might have a loose mount

TNJohn

That's a good idea. Any way to check without a hoist?

vmystikilv

Disconnect the battery and reset the system maybe....

wallyp

If two dealer service departments and one indy have checked the car hands-on and can't find anything, I'm afraid that a bunch of owners probably aren't going to help much over the internet...

I hope that I am wrong on that, but I would suggest that you take any suggestions with a grain of salt.

Mike5215

The air struts are made up of two components. An air spring that replaces what would normally be a steel coil spring up top, and a dumb old conventional mechanical hydraulic strut on the bottom. The AirMatic controller is really good about throwing a code when anything is amiss with the air springs, but the "dumb" struts can and do wear out, get tired and/or leak and become weaker over time and only a visual inspection or an obvious leak would tip you off. The hint is how the car can't recover quickly from pitch and yaw movement. AirMatic will sense that and move air around to compensate but it can't compensate fast enough if the struts themselves aren't holding up their end by rebounding quickly.

Normally the strut assemblies are suffering air spring failures and being replaced well before the mechanical struts have a chance to fail, but not always.

Sounds like fresh air struts all around would get your S back in form. Arnott makes a less expensive replacement unit that uses an OEM strut as a core, and they warranty them for life.

AlexMercedes

That makes a lot of sense, never thought about that before. Does this also apply to the ABC struts? Mine have no leaks or issues, but I gotta say, my ride quality is on par with an old Porsche...

TNJohn

Mike,

That makes sense! It's a breakdown of the dampening system that won't cause car to sag or throw codes. I know of no other way to get new hydraulic struts other than to buy the entire Airmatic strut. The air bags are quite sound on my car, so I hate to throw out the baby out with the bath water. But then again, how long will they stay that way at 11 years old?

I wonder how you could diagnose that since diagnostics won't pick it up? The old fashioned "push down on fender" trick?

cmpcpro

No the ABC is all hydraulic. They do have little black compensators, the name escapes me at the moment but they have a bladder in them and when you go over bumps in the ABC car the fluid expands into the bladder to help with the ride.

mcguirja

I think you are referencing the pulsation dampener or accumulators or maybe both?

tusabes

Mcguirja nailed it

you likely have one or more airmatic struts wth a good air bladder but a failed damper .

pushing up and down on each corner was indeed the traditional way to locate a bad strut on conventional cars, but might not identify the failed strut due to the air bladder providing dampening - but it's simple to check ! Give it a try and report back . You likely only have one failed strut

mercedesmorten

Hey all!
Was there ever any progress to this?
I have the exact same problem.

The car feels so stiff that the entire interior shakes and rattles when i drive over even small dents in the road. I feel lane markers, and writings on the road!
But it also feels loose with tons of body roll if i hit a pothole while cornering, then it feels like my rear looses traction for a milisecond.
All the while my car is so noisy from all the leather and plastic vibration.

My indy recently rebuilt the front suspension (however for some reason didnt replace the lower ball joints, which are no good anymore), but other then that, new upper and lower control arms, outer tie rod ends, and new front arnott struts.

I am currently riding 245/35/18 front and 275/35/18 rear.

I had become convinced that my problem is with the sidewall of my tires, but honestly it makes no sense, since i see so many people riding with similar (or even narrower tires!)

Do you guys really think the tires could mean this much?
Im trying to source a set of standard staggered 18" (245/45 265/45) to see what difference it makes, and ill replace both lower ball joints myself shortly.

Best regards,
Morten.

doni01

iTrader: (1)

Hi there,

I am also going through the same exact thing at the moment. No codes, just a stiff ride and no change in the suspension after pressing the button. Car rides in Sport 2 at all times. As a matter of fact yesterday I spent all morning with the Indy going through everything and reading actual values while driving the car. Found nothing. I changed my pump about two weeks ago since it had become very noisy through the years. Was hoping that was it but it wasn't. We spoke with a Tech from the Mercedes Dealership and he said that he has seen it few times and each time it was the valve block sticking and not throwing any codes. With that being said, I am doing the valve block next even though some people here on the forum do not believe that the valve block has anything to do with the dampening. Will see what happens...

TNJohn

My car has been sorted by the Mercedes dealer service department. It rides and handles 100% better. I left the car for one week while the master technician checked suspension values and drove it. No fault codes came up at all. All suspension components, including Airmatic struts, are sound. There were 3 components to the service:
1. Calibrate ride height - never done in my 3 year ownership
2. Another alignment
3. New Continental Extreme Contact DWS06 tires

Here's the mystery - I'm not sure WHY this worked or what was the magic bullet. The previous tires, Michelin Pilot Sports, were getting worn and loud. The new tires are of somewhat softer rubber. Hopefully this helps,

John

mercedesmorten

doni01:
Interesting what you'll find out when replacing/repairing the valve block.
I too, also have no codes or leaks. Raising and lowering the vehicle is fast and efficient. And it doesnt sink overnight.
However it feels like I am riding straight on the rims. Or have wooden tires.

I should correct my post on top, where i gave incorrect wheel sizes.
I am currently riding 245/35/20 front and 275/35/20 rear.
- fairly cheap tires too.

- The question is again, would you think that these wheels (that have inarguably low sidewalls), can provide such a harsh ride?
I seem to have read other people running 20's on their w220 and describing the ride as fine.

Anyway, im probably going to change them to 18" factory sizes and see what happens.

Best regards,
Morten.

mambodave

had similar issues the one I just bought. Ditched he old Michlens to continental contacts and 95% of the noises, vibrations and "stiff" shudders went away. Michs get noisy and hard when worn, especially if they are wearing uneven.