Arrie

The other day when I was measuring my 2013 S550 wheel well height around the car I played with the Different suspension settings.

With comfort setting the car was at 2 mm at both front left and right sensors and at 3 mm in the one rear sensor using iCarsoft MB II scanner. The distance from top of fender arch to ground war 28 7/16” on Front Left, 28 5/16” on Front Right, 28 5/16 on Rear Left and 28 3/16 on Rear Right. I did this measurement for someone asking for these measurements in an Airmatic discussion but I cannot find that thread anymore.

Anyway, when I set the suspension to Sport mode the car did not move down at all like my E550 does, which sets the car about 10 mm lower in Sport mode.

When I pressed the raised mode button the car went up 25 mm by the sensors so that worked.

When I drive there is a big difference in suspension stiffness between Comfort and sport, which comes from the shock absorber setting but by the above it seems the S560 ride height is the same between Comfort and Sport.

Does anybody know if this is the correct behavior of the Airmatic system in S-Class?

BOTUS

in the handbook its states it drops the ride height at speed by 20mm (that's about 3/4") and then goes back to set point at the vehicle slows

the raised height stops after 70mph or if you do between 50mph and 70mph for more than 3 minutes

if you use raised height but drive lower than those conditions it stays raised even during key on / off

ABC does it by 15mm about 11/16"

Arrie

So, when the car is parked or not moving it keeps the same height in Comfort and Sport modes. Raised position works though but it lowers automatically at high enough speed for long enough. This is the same with E550 I have.

BOTUS

I thought it dropped 10 mm in sport but never saw it happen - but reading my manual it clearly says it goes down in comfort or sport above 70mph

conmee

I have a 2013 S550 4Matic and I recently had the original front right Airmatic strut replaced with an Arnott brand air strut at 69,986 miles by a local Mercedes shop. Since the replacement, the front is noticeably higher than before the strut replacement. I visited my local MB dealer and they said they checked/calibrated the suspension but it still looks higher than before to me. So I took some measurements. I don't have any other measurements to compare to except Arrie's in this thread. Granted, it's only a data point of one, but my S550's suspension is between 1/4" to 1/2" higher than Arrie's at Comfort mode height. So I assume that my S550 front end will now simply sit higher permanently. Would a faulty Airmatic valve block or sensor cause the differences in ride height between each strut? Based on measurements, it looks like all four struts drop the same amount in Sport mode +/- 1/16".

Some of the measurements caught my eye: The front left sits 1/4" to 3/8" higher than the other three struts in Comfort. The left rear strut rises the least of all struts in Lift mode by 1/4"-1/2" (would that indicate a failing strut?).

Just mildly annoyed as pre-replacement the car height looked great in Comfort and Sport modes. Wonder if I should have replaced with a MB strut or replaced both front struts with Arnott even though expensive. I could get all four struts replaced with Arnott coil over non-airmatic struts for the price of 1 1/2 Airmatic struts (more or less) and that would likely solve ride height permanently. But I'd hate to give up Airmatic (despite repair costs) and the ride comfort just because the ride height is now "off" from what it used to be.

Thanks MBWorld for letting me ramble/rant. Not sure I have anything in here that can be answered, but hopefully at least my measurements will be an additional reference point for fellow W221 owners should they have questions about ride height in the future.

BOTUS

the three level sensor need to be moving freely to do this - the link rods need replacing every few years, as the link rod ***** seize in the sockets. One each side at the front, and one well hidden at the back.

there is a procedure to follow to get it to actually remember the settings and the idea old bushes and old / new struts and level sensors will allow the Factory method to get it right is plain stupid.
It kind of matters where your measurements are coming from. From the floor inline with the Star of the wheel centre to the start of the body work is more like 29.5 (750mm) in each corner when its in the correct place - so both sound low to me
height is not how Merc do it - they get the pump and air in the struts warmed up - first exercising the suspension through a range of travel and using magnetic sensors on suspension struts it feed reading you put back in to the system

BOTUS

to see the level temps >15C after at least a 5 mile drive to warm up the struts, then stop Engine running on perfectly level ground park brake off ... ANY other conditions it will always be random

Arrie

1. Make sure the floor under the car is absolutely level when you measure the right height.

2. The air spring itself does not set the right height. The spring moves the car up/down but the position is set by the level sensor. If your air spring is different from the other(s) it may take different amount of pressure for carrying the car (if diameter is different) but the right height still is set by the sensor so if the height changed somehow the sensor reading changed.