Air Suspension Failure?

[Castro13]

Originally Posted by MCollection

If the compressor is running the relay should be ok. The ehc control unit has a timeout function to protect itself from burning out which it doesn't do very well. If the compressor can be heard without listening hard it has probably failed, they become noisy when overworked.

I suspect the ehc knows the compressor is not inflating the bag and turns it off.

The compressor has a hard plastic piston ring and when bags are slightly leaky the compressor has to over work but not to the degree to timeout so it wears prematurely. There is also attached to the compressor a valve block that get stuck and won't let air in or sometimes out.

I would guess at some point the bags were leaking for a while gentry before replacement which wore the compressor early now it's just failed.

As an aside all the aftermarket compressors are much cheaper but usually come without the valve block so if this the issue that needs changing too. The genuine bmw ones are expensive but come with valve blocks. Valve blocks not available as separate part from bmw but can be found on eBay etc.

If it was me I would get a quality replacement compressor like bilstein or arnott and a valve bloack from eBay and replace as one.

Also bear in mind there are two valve blocks as some ehc pipes are different sizes.

I have changed loads of these bags and only once did I do it as per instructions where I cut the pipe and pushed it in and that was the only one that ever leaked. I always undo the brass fitting with a 10mm from the old bag then hand tighten it into the new bag as to not pick up the plastic threads (the air pipe makes it feel funny going in) then nip up with a spanner.

Always spray the system with soapy water and check for bubbles forming, if you can't access use your phone camera to reach.

Compressor turns on for 10 secs and then shuts off. Is there anyway of testing the piston or valve before buying a whole new compressor?

Thanks!

[///MCollection]

No there isn't. The piston ring used to be replaceable in the e53 x5 but not anymore. Could do with a fault scan to check before you spend out. If it's timeout fault it will be compressor.

[turboawd]

You check if the level sensor is connected?

[Castro13]

Originally Posted by turboawd

You check if the level sensor is connected?

I have not. How would I check it? Disconnect and move up?

[Castro13]

Have the same symptoms as in this video. I can stop the air with my finger from the valve block. Per the video and shouldn't be able to stop the air flow with my finger. I've almost certain it's the compressor that's bad. Going to test the air strength before it hits the valve block to make sure its not the valve block.

Update: opened up compressor and piston looks excellent. The issue is the solenoid or the little white balls. Took some balls out and hit the solenoid. Hoping for best.

[raducris]

Originally Posted by Localbrew

Randomly but I noticed it a couple months ago, but like I said it only happens on slanted parking or uneven surfaces.

I'm new to this subject as it just happened to me the other night while being parked inside. I'm assuming that the random part happens only when you park on uneven surfaces as that is the time when the self leveling air system is trying to compensate, by opening the air exhaust valve (and can't close it back properly)
What confuses me and I am still digging for info is how this purge valve works in conjunction with the block valve, the 2 other solenoids that do the L and R separation. I was under the impression that, when the car is parked, all these 3 solenoids should be normally closed. So, to me, if the purge valve doesn't close properly, there is also the block valve that should prevent deflation while parked. Unless some software bug opens these valves on its own... randomly

[mattingamells]

Renewing this thread and looking for some help please. My 2016 F15 has started to drop on the passenger side even with brand new Arnotts.

I think that I either have a faulty discharge valve or a faulty solenoid block.

My question is, wouldn’t a faulty discharge valve result in both sides deflating rather than just one?

If so, and it’s actually the solenoid block, does Arnott do one that is compatible with the F15? I’m not seeing one but wondering if the one for the previous X5 will work (Arnott part number VB2898)?

Thanks in advance,

Matt

[mattingamells]

Follow up…I have been reading a lot of posts where owners state that the compressor kicks in when they unlock the car. Mine only fires up if I start the engine.

What should the normal operating procedure be?

[Tritan84]

Originally Posted by Castro13

Have the same symptoms as in this video. I can stop the air with my finger from the valve block. Per the video and shouldn't be able to stop the air flow with my finger. I've almost certain it's the compressor that's bad. Going to test the air strength before it hits the valve block to make sure its not the valve block.

Update: opened up compressor and piston looks excellent. The issue is the solenoid or the little white balls. Took some balls out and hit the solenoid. Hoping for best.

Any luck with finding the issue? I replaced my bags about a month ago due to sporadic deflation. I thought everything was fine until today when I found both rears completely deflated. I can hear the compressor turn on for about 15 seconds but the rear isn’t raising at all. I’m guessing it’s the solenoid after watching that video.
What was your ultimate solution?