Slow suspension sagging on Airmatic CLS

[C240Sport97]

My CLS started to lose suspension height late last year after it is parked and not used for some time.

If I don't use the car for more than 3 days, the rear n/s drops a bit. The longer I don't use the car, the more it drops.

Having not used the CLS for about 3 weeks, 3 corners have dropped, but 1 corner remains standard:

Rear n/s: 2.5 ins
Rear o/s: 1.75 inches
Front n/s: 1.75 inches
Front o/s: normal

When I start the car, I get no warning lights and all 4 corners get to the right level quite quickly.

Any thoughts or ideas as to what is causing this? Clearly a slow air leak somewhere, but where?

Car has done about 17k miles, and was registered March 06.

Thanks.

 

[Deleted member 37751]

There was a thread about this very same thing not long ago and I can't seem to find it

 

[C240Sport97]

There was a thread about this very same thing not long ago and I can't seem to find it

I think there was one about one conrer (rear) sagging only, and needing a whole new strut (i.e. airmatic strut was leaking) .. discussion was about whether both sides needed to be replaced.

 

[momomo]

Sean i believe it is normal for the Airmatic to drop and "sag" a bit if it is left parked up for a while. Is it parked on even flat ground?

As long all four corners get up to the right level quickly and without any funny noises from the pump its all fine. And also if the pump is not operating more than normal or for an extended, constant period of time when your using the car or start it up, you wont have a leak.

 

[C240Sport97]

Sean i believe it is normal for the Airmatic to drop and "sag" a bit if it is left parked up for a while. Is it parked on even flat ground?

As long all four corners get up to the right level quickly and without any funny noises from the pump its all fine. And also if the pump is not operating more than normal or for an extended, constant period of time when your using the car or start it up, you wont have a leak.

yes, parked on even flat ground.

no funny noises.

may be 'normal', but it didn't sag at all for the first 8 months after I got it.

 

[C43AMG]

Is that the longest you have left it Sean ?

 

[C240Sport97]

Is that the longest you have left it Sean ?

thinking about it, yes ...

 

[BlackC55]

The pipework has to be checked for leaks as well as the pump and strut tops.

The pump effecincy can be checked with a star.

 

[SSR]

I've got almost exactly the same problem as the OP with my CLS. The n/s rear sinks overnight, so does the o/s rear, but not quite as much as the n/s rear. Fronts are fine. Took it into the dealer and got it hooked up to the diagnostic machine. They couldn't find any fault code. They also checked all the pipes for leaks and couldn't find any. Therefore they said they couldn't do any repair under the warranty.

Most frustrating as the dealer acknowledged that the car sinking down overnight wasn't normal, probably a slight leak in the rear shocks, but also gave a big story about airmatic in general that the pump/relay can burn out over time too - and to bring the car back in as soon as any fault appeared in the dashboard display.

Left the dealer over £100 lighter and frustrated.

 

[corned]

It is nature's way of telling you to get out in it more, Sean! Don't leave it so long between drives...

 

[C240Sport97]

It is nature's way of telling you to get out in it more, Sean! Don't leave it so long between drives...

it was out a lot on Sat ..

the discs had rusted quite badly on the front .. so much so that braking was causing s/w to vibrate.

so .. lots of hard braking later .. discs now shiny again, and judder gone.

phew.

was mad accelerating hard, braking hard .. repeat, repeat and repeat again on quiet motorway stretches. Fun though.

 

[Simon_M]

Sean,

Dean was the one who posted about this problem on his SL, maybe it is due to the colour?

My discs were rusted to bits after 2 weeks in the airport carpark, but as you said some 'abuse' sorted them out.

Simon

 

[C240Sport97]

Dean was the one who posted about this problem on his SL, maybe it is due to the colour?

best you stay in your current career

 

[SSR]

Update on airmatic fault

I've got almost exactly the same problem as the OP with my CLS. The n/s rear sinks overnight, so does the o/s rear, but not quite as much as the n/s rear. Fronts are fine. Took it into the dealer and got it hooked up to the diagnostic machine. They couldn't find any fault code. They also checked all the pipes for leaks and couldn't find any. Therefore they said they couldn't do any repair under the warranty.

Most frustrating as the dealer acknowledged that the car sinking down overnight wasn't normal, probably a slight leak in the rear shocks, but also gave a big story about airmatic in general that the pump/relay can burn out over time too - and to bring the car back in as soon as any fault appeared in the dashboard display.

Left the dealer over £100 lighter and frustrated.

Just to help anyone out with an airmatic CLS who might be having a similar issue as the OP and my quote above. With the car still sinking down overnight, I took it back to the dealers earlier this year. After much checking and replacing of parts e.g. a couple of valves in the airmatic system, but still no fix, it turned out it was a leak that had been causing the problem the whole time. The leak was in the hose that comes from the air reservoir can to the n/s rear suspension. The whole air bellows (with hose and can attached) had to be replaced - big expensive job cos' the rear axle had to be dropped. There's a thread somewhere (not sure if it's on this site or not - I can't find it just now) where a guy had exactly the same leak on his E class w211 airmatic and was able to do a diy repair, replacing the aluminium reservoir can and the attached hose without fully dropping the rear axle. Incidentally, I mentioned this to the dealer when I picked my car up and the mechanic (sorry, technician ) said yes it was possible to do the fix that way, but the instructions on the air bellow specified that the hose shouldn't be disconnected from the reservoir or bellow - therefore the whole rear axle had to be dropped. Hope this might be helpful for someone. Have to say I'm loving my CLS now that it's running so well.

 

[C240Sport97]

Just to help anyone out with an airmatic CLS who might be having a similar issue as the OP and my quote above. With the car still sinking down overnight, I took it back to the dealers earlier this year. After much checking and replacing of parts e.g. a couple of valves in the airmatic system, but still no fix, it turned out it was a leak that had been causing the problem the whole time. The leak was in the hose that comes from the air reservoir can to the n/s rear suspension. The whole air bellows (with hose and can attached) had to be replaced - big expensive job cos' the rear axle had to be dropped. There's a thread somewhere (not sure if it's on this site or not - I can't find it just now) where a guy had exactly the same leak on his E class w211 airmatic and was able to do a diy repair, replacing the aluminium reservoir can and the attached hose without fully dropping the rear axle. Incidentally, I mentioned this to the dealer when I picked my car up and the mechanic (sorry, technician ) said yes it was possible to do the fix that way, but the instructions on the air bellow specified that the hose shouldn't be disconnected from the reservoir or bellow - therefore the whole rear axle had to be dropped. Hope this might be helpful for someone. Have to say I'm loving my CLS now that it's running so well.

how much did it cost to fix? did a warranty of some sort cover part or all of the cost?

 

[SSR]

I was glad it was covered by my official Merc 1 year used car warranty - dealer told me it was just short of £1500 for the part and labour! And apparently this didn't include the various valves they replaced (unnecessarily) before they got to the real route of the problem.

 

[jaymanek]

If it is creeping down over days it is ok... the system will release a little with age... If it starts creeping down within hours, then you have an issue..

 

[C240Sport97]

car has recently been parked in a different and level space ..

it has stopped sagging and is perfectly level