Suspension compressor burnt out?
 

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

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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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)

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

Any idea how much a bag is?

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!

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.

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

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.

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

Oh right, I think I remember that. Going to try and get some cheap ones, recommendation?

I suppose you can replace them with standard tools?

Find a YouTube video air bags are an easy repair. Bags are not very expensive you can buy a quality brand without breaking the bank


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Arnott Industries for replacement bags - Last I recall they are around $220-ish for the pair, delivered.


Do you have sports package? If so yes you will need the "sport" rear air bags - The non-sport models and all EHC2 vehicles (including 4.8iS) need the "comfort" rear bags, because of the articulating suspension on the 4-corner air models.


I would replace the bags first and then see - there is a *chance* that the compressor does not need a rebuild, however, if you've been driving on leaking bags for a while the compressor is overworking itself trying to keep inflated, it does not take long.


What the module sees is a filling spec from the compressor, once it gets "tired" or worn out from continuously trying to keep leaking bags inflated, it can no longer fill the accumulator within a certain spec. Then, even if you replace the bags and it will hold air, you still will have the fault on the dash.


If the bags are replaced and no longer leaking, and you go into the module to read the error if the fault remains on the dash, and you see something along the lines of "Accumulator filling requested pressure remains constant", then you need to rebuild the compressor and then reset the faults in the module.


It doesn't "turn off" so to speak, its either operating as needed in normal operation (filling of the tank when needed), or its working constantly when the vehicle is running because the air tank is filling the bags and the compressor is needing to keep the air tank at a certain pressure.


If that makes sense.

There are different rear air springs for a standard (air) or sport (air) suspension. Compare two options in Europe: BMW genuine parts or Arnott Europe.

If you travel to the US, they are less money in the US and easy to transport in a suitcase (trust me on this).

I just noticed you're in europe. if your compressor is still good. see the info below to repair it:

Link to purchase the repair kit for compressor

Link to repair Compressor

andrewwynn Found a video, seems like a quite easy thing to do.

Ricky Bobby Yeah I think I got it. I will start by just replacing the bags, depending on shipping time I might order a wabco kit to have just in case.

Gregory891 Ok. I do not think I will be in the US any time soon. Will stick with the sport. Just wondering, could you put normal ones on?

donmayor Yeah, shipping fees from the US would be terrible. How can you tell if the compressor is repairable?

Once again thank you so much.

Hi again!
According to this thread : https://xoutpost.com/bmw-sav-forums/...bag-my-x5.html

I need airbags with part the numbers below as I also have SPORT selflevel suspension.
left rear: 37126750355
right rear: 37126750356

Does that seem right?

In that case, these would fit, right?
https://www.ebay.com/itm/18314784710...m=183147847107

I can't read German - but yes you need the *sport* rear air bags

that airbag doesn't look like the sports ones.

But they are supposed to have oem numbers 37126750355 and 37126750356, right?

Suspension compressor burnt out?
 

Duplicate post

https://www.arnotteurope.com/product...only/2002.html

Pick your year (it shouldn't make a difference) and order the left and right sport bags from Arnott Europe. Parts already in the EU, easy to ship from NL to S.

Remember - rubber degrades over time. Add the changes in climate from summer to winter and back, as well as air pressure - it is simply inevitable that an air spring will need replacement. The good news, they are MUCH easier to replace compared to a coil spring.

Actually just ordered some from ebay, seller claimed they should fit. Part number is the same as the oem ones and the arnott ones. Was just 80usd, not much to loose.

By the way, moved the car in the driveway yesterday, the compressor came on along with a hissing sound from the leaking bags. Pulled the 30amp fuse to not overwork it.

Thank you everyone for the help!

I thought I would just update the thread so potential readers in the future would know.

The eBay ones work great, but the connection at the top was 1 millimeter too tall so I had to sand/grind it down. But after that, the plastic clip snapped into place.

I think it was well worth to get some less than half the price of the Arnott ones.

Something I learned was that pulling the 30 amp fuse nr 87 turns it off but putting it back in doesn't instantly turn it on again. Pulling the 7,5 amp fuse nr 79 out and in did instantly turn it back on.

EDIT: But the SELFLEVEL SUSP.INACT is still on, will it turn off after driving for some time or do I have to take it to a mechanic?

Has to be reset by a mechanic who has BMW software - the EHC module faults are "hard codes" - they won't reset on their own