2016 BMW X5 F15 rear air springs deflating (Ireland)

[_garycurran]

First post here, cant really find any answers to my issue anywhere, basically I had the typical rear end sag a few weeks ago, I was able to verify that my compressor was running but air springs not inflating, with just over 100k miles on it I figured it had to be the bags, (although I thought unusual for both to go at the same time, but not uncommon).. I'd rather change both anyway...
So that's what I did, two new air springs in, still nothing, compressor still running but nothing happening to the rear end..
So removed the compressor and removed the solenoid from it, put 12V DC to the pins and nothing, lubricated and cleaned and eventually after a few minutes it started firing again... I was happy that this was my problem.. put everything back together and back onto that jeep, low and behold it started rising..
That's until its left parked up and it slowly deflates fully again, so I bought a brand new compressor and valve block to rule out the rest, again it started rising but it slowly deflates overnight. I can't hear any hissing noise to suggest I have a leak anywhere, it also self calibrates so its not a computer issue... I'm lost now as to what the issue is.. all parts have less than 200 miles on them... anyone with any ideas????

[_garycurran]

I know there's a lot of posts on rear air spring issues, but I cant find any with the issue I'm having....

[kangfu84]

I had similar issues but luckily mine was remedied with new air bags and then the compressor shortly after once that failed also. I did though during my research find some other possible causes that may help?

• Ride height level sensors, they can sometimes get stuck or faulty. Some have fixed with WD40.
• Compressor relay (in the trunk, next to the fuses. It's light green in colour). Some people noted this kept tripping causing the compressor to shut off and replacing the relay fixed it.

[_garycurran]

Originally Posted by kangfu84

I had similar issues but luckily mine was remedied with new air bags and then the compressor shortly after once that failed also. I did though during my research find some other possible causes that may help?

• Ride height level sensors, they can sometimes get stuck or faulty. Some have fixed with WD40.
• Compressor relay (in the trunk, next to the fuses. It's light green in colour). Some people noted this kept tripping causing the compressor to shut off and replacing the relay fixed it.

Yes, I've replaced the relay also for genuine BMW part, and also plenty of WD-40 on sensors, cleaned etc.
only thing I've left to try is air lines from valve block to bags, I will go along them with leak detector spray and see if I can find anything.

[kangfu84]

Originally Posted by _garycurran

Yes, I've replaced the relay also for genuine BMW part, and also plenty of WD-40 on sensors, cleaned etc.
only thing I've left to try is air lines from valve block to bags, I will go along them with leak detector spray and see if I can find anything.

Bummer man, best of luck. I know how much of a pain it is troubleshooting this stuff. I hate that these cars are so good otherwise.

Have you scanned for error codes?

[_garycurran]

Originally Posted by kangfu84

Bummer man, best of luck. I know how much of a pain it is troubleshooting this stuff. I hate that these cars are so good otherwise.

Have you scanned for error codes?

yep, no faults stored

[Chilled]

Originally Posted by _garycurran

Yes, I've replaced the relay also for genuine BMW part, and also plenty of WD-40 on sensors, cleaned etc.
only thing I've left to try is air lines from valve block to bags, I will go along them with leak detector spray and see if I can find anything.

Hey don't forget those brass fittings. With the way the lines fit in/out and the locking compression collar/ring. It kinda makes them a one time use (hard to remove line without deforming even more pita to re-install.

When you are installing the fittings. You are supposed to install them into the air-bag/compressor first and then insert the air line into the fitting.

[_garycurran]

Originally Posted by Chilled

Hey don't forget those brass fittings. With the way the lines fit in/out and the locking compression collar/ring. It kinda makes them a one time use (hard to remove line without deforming even more pita to re-install.

When you are installing the fittings. You are supposed to install them into the air-bag/compressor first and then insert the air line into the fitting.

Thanks for that, yes I remember seeing those collars, just wondering should the tapered end of the collar be inserted first or the other way around, I will double check them this evening.

[Chilled]

The tapered side of the collar gets pressed against the fitting it self when you give the line a pull. The install process is, install fitting, push in air line, then give it a tug. The pull forces the collar back against the fitting housing and crimps the line abit.

If you are going to the effort of replacing the air lines, just do the fittings. Cost wise they are fairly insignificant.

[jfandl]

I had a factory original AB fail on me so I replaced it with Arnott AB's. The first two I got had one that was leaking at the clamp. I got it replaced, the replacement was also leaking at the clamp. Finally, a third one that was hand tested before shipping solved the issue. I don't know if they have quality control issues but a spray bottle with dish soap and water are a handy way to check for leaks.