Airmatic losing air in S mode but not Comfort
 

Rear Passenger
So pretty much what the tittle says ,
was anyone able to find out what it is ?
my bet is that the strut leaks air.
I already changed out my rear drivers side back in th day but i dont remember it was doing this ,
but instead it would sag in whatever mode. (is what i at least remember).
which could lead to a completely wrong part.

any help is very appreciated

Those 2 modes use 2 separate chambers, so sounds like 1 of them leaks.
So you dumped troubled Bluetec to get this instead? ;)

Are those chambers behind rear bumper on the bottom drivers side? Or is it inside where the air tank is ?

Nah man you probably mistaken me for someone.
Ive had this e550 since 2013😀

You know the drill, scan, perform leaktightness test and you'll know for sure. My guess would be a leaking air bag. I know nothing about the 2 chambers, but it doesn't matter, once it leaks it has to go. These should be replaced in pairs to avoid situations like these. How many miles did they last? (1st and this one)

https://cimg0.ibsrv.net/gimg/www.mbw...60114df4db.jpg

Are you sure these are from a W212 chassis?
From what I know there are no electrical connections going into these bags, only in the struts which sit on the outer part of the bags. The fronts bags are built with the struts going through them, but the rears are independently placed.
I'll have to open mine when they fail and then we will know for sure.

Honestly that would be my guess as well , leaking air bag.
But at the same time , these chambers sounds like a potential reason as well ,but im inclined towards the air bag. Unless someone can confirm otherwise.

Well my left lasted around 100k. And right now im at 140k

Thats what i thought..looks a little different

The google picture shows concept, not your personal part. If you spend time to understand it, you can figure out what area the leak might be.
But even without much investigation, high chances are you need new airbag.

That's respectable, if I get 140k out of mine I will be very pleased. Right now they're at 121k, all original but I'm expecting them to go withing the next year or so, these things don't usually go for more than 10 years.
If you don't have the means to do the leak test yourself I wouldn't bother taking it to a shop. They'll charge at least half of what a new replacement bag would cost anyway just for the diagnostic. Did you use Arnott for the one you replaced at 100k?

yea man , honestly i dont feel like doing any diagnostics , since there are not that many parts involved i can just start with the one that i think is the cause , which is the air bag. and then if it doesnt help ill look for system leaks.

yes i did use the Arnott one for about $210 i believe,. Right now i found one on rockauto for about 180 shipped which is a steal.

Catching up to me on your mileage there lol

also thinking about brake fluid flush in the near future and powersteering fluid change.

swapped out rear right air bag with the new Arnott one. we will see if the problem went away.

Good luck with it, hopefully it solves your issue. Let us know how it goes. Mine is still behaving, for now :))

You still got originals?
Must be nice !!

This exact thing happen to my E550 when i had it. It is going to get worse within next the few month and it will start leaking air in Comfort mode as well.Perhaps you remember we spoke about it six month ago or so.I would recommend you to start saving for a new air strut.

Yep, it's still rocking the originals. Haven't really had issues with my Airmatic except for the auto damping wire coming from the Airmatic unit to the rear left shock. Replaced the shocks for no reason, replaced the wire coming from the X62 plug to the strut for no reason but the issue is still there. Only manifests when it is cold, usually below 32F. I finally realized it's a cold solder joint on the control unit itself misbehaving, but ended up spending >1000$ throwing unnecessary parts at it. Luckily I moved to a warmer climate and all is good for now. I might resolder the strut damper pins on the control unit when I have some time, that should take care of the issue.
The bags however are fine. I want to see how much mileage I can squeeze out of them, I'm aiming for 155k so I can get the badge.

I still have originals in front at 166000 miles. Rear springs were changed at around 40000 miles but not for leak in the bag itself. It was a bad seal design thatMB used first. The new bags they installed are supposed to be with new better seal design.

And you can get the badge regardless what is fixed on your car.

I know, but it would still be nice to know they can last up to 155k on all original suspension parts. It seems like a lot of people have had issues with Airmatic, mainly bags leaking air way before the 155k mark. Fronts don't seem to fail as often but rear bags are going out for most people, regardless of manufacturing date or updated part numbers. I wonder if the issues are related to driving style/road surface conditions more than manufacturing flaws. I don't push my car too much, no hard cornering or sporty driving in general and I try to avoid potholes as much as I can.

I had it in comfort for at least 2 or 3 months , and throughout this time it deflated 2 times in comfort and on sport it would do it all the time. 2 days after replacement and so far so good.

The last two mornings I've gotten into my car it's had to "rise". It has done it before, but never two days in a row. I'm worried that I'm going to have to replace my airbags soon too. :mercy:

I have an E55 that is not consistent in regard to the rear air springs. The car is garage kept, but during last winter the left rear would slowly loose about 1/2-3/4" of height after a week or so of sitting. Last month I parked in sport 1, both sides of the rear dropped to the axle after just a few days. Then it did it again ,(more on the left), after a few days sitting in comfort mode. I parked it for a week in raised position for a week, and no drop in the rear. Been sitting for 9 days now, parked in comfort,and maybe 1/4 drop in the left rear, Never a dash warning, and I don't hear the compressor. The car has 130K miles. Unless the vent/fill valves mysteriously opened, the airbags must be self healing. No codes either, and fronts are fine.