Suspension compressor burnt out?

[Nilsmogensen]

Hi! I did search the forum for some answers to this but did not find anything matching this.

2003 4.4 E53 sports package. (no adjustable suspension)

I drove the car for like 40 minutes and then parked, noticed a hissing sound and after a few minutes, it was really low. Did not think much about it, previously the car has been slightly lower after sitting for a couple of weeks. I later started the car, pretty sure I heard the compressor come on. After 20 minutes I got the "SELFLEVEL SUSP.INACT" message on the dash. Pulled over and noticed the rear left suspension really sunken down. During the last few days, the rear right suspension also has begun to lower.

I THINK that I have had some slight leakage in the air springs during quite some time. When one of them got a much bigger leak it overworked the compressor which then failed. So new air springs and compressor??

I have checked the fuses in the boot, 79 87. And also 57 in the glovebox. All was fine, (dropped fuse no87 so not sure about that one) All working fuses now. Is there any hope that the compressor can be saved without replacing it? I assume air shocks have to be replaced?

Regards Nils Mogensen

[andrewwynn]

If the leak is too big for the compressor to keep up I will meet it's designed to shit down the system. Good odds the bag is just blown.


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[Ricky Bobby]

Replace the rear air bags, and hopefully you didn't burn out the compressor - It should not sink when sitting, if so there is a leak - if your bags are original, due to age I suspect they are dry rotted/cracked


There is a suspension rebuild kit for the pump seal, which is the part that goes bad - its used on VW air suspension models - if you search "Wabco compressor rebuild kit" it should come up


If you replace the bags and have the error cleared, and there is no leaks or sagging, but the error comes back on and stays, its likely the compressor throwing a code. I'm sure you probably know but you can't "disconnect the battery" to clear the errors on the EHC module, need dealer level software (DIS/GT1)

[Nilsmogensen]

Originally Posted by andrewwynn

If the leak is too big for the compressor to keep up I will meet it's designed to shit down the system. Good odds the bag is just blown.


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Shut down or shit down? How would one get the shutdown system in action again?

Any idea how much a bag is?

[Nilsmogensen]

Originally Posted by Ricky Bobby

Replace the rear air bags, and hopefully you didn't burn out the compressor - It should not sink when sitting, if so there is a leak - if your bags are original, due to age I suspect they are dry rotted/cracked


There is a suspension rebuild kit for the pump seal, which is the part that goes bad - its used on VW air suspension models - if you search "Wabco compressor rebuild kit" it should come up


If you replace the bags and have the error cleared, and there is no leaks or sagging, but the error comes back on and stays, its likely the compressor throwing a code. I'm sure you probably know but you can't "disconnect the battery" to clear the errors on the EHC module, need dealer level software (DIS/GT1)

As far as I know, the bags are original. Wabco kit seems like great value, 23USD. Do you think the compressor could come back to life if I change bags? There is no sign of life at all.

Any idea how much the bags are?

Thanks for the replies both of you!

[andrewwynn]

The compressor isn't working on purpose the dashboard is telling you that. You need to read the codes to see why the system is inoperative. My suspect is that after it spent enough time trying to fill a busted bag it knows to disable the compressor and flag the system inoperative until it's repaired.


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[Nilsmogensen]

Originally Posted by andrewwynn

The compressor isn't working on purpose the dashboard is telling you that. You need to read the codes to see why the system is inoperative. My suspect is that after it spent enough time trying to fill a busted bag it knows to disable the compressor and flag the system inoperative until it's repaired.


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Would be great if it did turn it off. Would the car sense if I replaced the bags or would I have to reset something? As Ricky Bobby said it seems like you may have to reset the fault code as well, so I might as well restart the compressor at the same time at the dealer.

[Nilsmogensen]

Thank you so much for the replies so far!
Do I need to get special bags for the sports package?

[andrewwynn]

For a minor fault the system will reset from simply restarting the car. For a major leak problem i would not be surprised if there is a permanent code that needs to be reset like air bag faults.

[andrewwynn]

Originally Posted by Nilsmogensen

Do I need to get special bags for the sports package?

From my understanding air bags are exclusive to the sports package. I could be wrong but sports package starts with air suspension rear.