Help...on CA/ball joint job. Air springs won't refill, jack is stuck

[Olly84]

Not sure where to post since it's touring specific and also not. So..

I was so close...BJ, Control arms, rear shocks...all done, installed, pre-tightened everything...it was a bitch and a half to get the swing arm and integral link to line up, but I did it. I was seeing the light at the end of the tunnel.

Forgot to measure pre-load height in the beginning so I put the wheels back on to lower on ground and measure height to jack up again and finalize torque.

I bled out all the air in the SLS earlier so i re-tighten the red and blue hose connector.

Turn car on to try to engage air pump (here's where the trouble starts) I thought i heard something "whirring" in the trunk so I thought that was the air springs coming back to life. I turn off the car assuming the springs had some air in them and proceed to lower the car. Turns out the whrring noise was NOT the SLS pump (maybe it was the cd changer i don't know, i was so tired). Car comes down way past its usual point and lands on my jack under the differential before I knew what happened. Luckily there was a piece of wood between jack and diff but rear of jack is digging into fuel tank because the rear is like a low rider right now. I'm freakin' out a little to be honest, but will plan to use the factory jack to lift one side up to extract my big jack.

I tried to start the car all the way to see if air springs would inflate. Engine comes to life, but nothin' in the back. dead silent, no pump. I check the red and blue hose connection and it's completely tight. Disconnect and reconnect battery to see if it'd reset the SLS. Nadda! Tried the key in ignition position 2, and no sls pump noise. Tried to start the car again and then....click click clack clack clack...

and now to add to the misery, the car won't turn over at all after I disconnected the battery. Car has electrical power though, headlights, heated seats, everything turns on though. What on Earth gives?

Would the cold have something to do with the power? Could me messing about with the wheel hub and swing arm combo have damaged the air spring?? I mean, I had to really man handle, twist and turn the wheel hub and swing arm to get it to line up for the long ball joint bolt. Air bags are new and were replaced 2 years ago, less than 10k on them. No fault codes at all relating to SLS.

Please help. This is going on as a 3 day job now since it gets dark fast and very very cold at night.

IMG_0774.jpg

[StephenVA]

Check. Battery voltage

[Olly84]

Car did started up perfectly fine the first time when I tried to re-inflate airbags. Does disconnecting battery make it lose juice?

Check. Battery voltage

[CPHES]

You could have killed the battery during the work you were doing. Or you did not get a good connection. Make sure the ride height sensor is attached on the right rear control arm - that tells SLS what to do. Without that, it does not lift. With the car off, and the hatch or gate open, sls will try to pump up to level.

[Olly84]

Hmm, I was extremely careful to reassemble everything the way it was, but I'll check the sensor tomorrow morning...

I don't know how I could have killed off the battery during work though =X. It was 3 days, but the car was off the entire time besides the doors being open etc.

[philly98540]

Put a charger on the battery.

[Olly84]

alright, battery was just dead for some reason. Jumped it and car starts. So random, will probably replace battery soon.

But the inability of the air springs to re-inflate is still there =X

[Olly84]

I mean, the SLS is a really simple system. could only be so many things to not make it pump. I'll investigate more in the morning.

right now the car is literally slammed to the ground, I can't even jack it up with my slim floor jack. The only thing that will remotely work to get it off the ground first is the bmw jack.

Is there any danger of the arms and shocks getting damaged while the car sits like this? It's even lower than what most people experience when they lose air.

[CPHES]

It’s likely going to be ok. You are at the end of travel for the suspension. It could be that your compressor is not strong enough to pump it back up. I had a compressor like that. It was ok until I pulled / swapped the right airbag. I put a new/used compressor in, and the car came right up. In my case, you could hear the bad one run, but the car stayed on the ground. It will be hard for you to get to the sensor will the car flat. I was able to use the access holes on the floor to get to mine - near where the bag sits. Also check the fuses.

- - - Updated - - -

Good background info.

https://www.bimmerforums.com/forum/s...#post_29517054

[dannyzabolotny]

See if you can get the compressor to work at all? Check the fuse for the SLS, maybe it blew? If the fuse is okay and the compressor is getting voltage then it’s likely a bad compressor.

If your compressor is actually bad, I’ve got a known working one from a parts car 540it that I could send you.

[Olly84]

See if you can get the compressor to work at all? Check the fuse for the SLS, maybe it blew? If the fuse is okay and the compressor is getting voltage then it’s likely a bad compressor.

If your compressor is actually bad, I’ve got a known working one from a parts car 540it that I could send you.

btw sorry for posting in both forums

Hey Danny, I've checked the fuses and it says intact. Funny thing is when I pulled out the fuses, the car gave me an SLS inactive message. When i put the fuse back in, i could hear the compressor make a click noise, but that was it.

I mean, I'd love for you to send me the compressor. I'll paypal you for it plus the shipping. I don't want to drop $500 on a new compressor =X but at this point, I'm thinking it's either the compressor or the ride height sensors (even though i didn't break them or mess them up during suspension overhaul). If it was hoses/air bag i'd at least hear a hissing noise? I just don't know how to check if sensors are working because i can't even drive to a mechanic, the rear is so low the tires are rubbing against the fender.

Just a little confusing becausae I always hear the air pump kick on when i start the car before I started suspension work.

[dannyzabolotny]

The sensors would throw error codes in INPA if they were bad. Now what may have happened is the sensor arms went backwards which would give the SLS a ridiculous reading. So as a last ditch effort, I would try to get the rear of the car up by any means possible— get creative! Then when it’s up, verify the sensors are sitting correctly and try to get the compressor to fire up.

If that doesn’t work, PM me and we’ll work something out for the compressor.

[rdl]

Try this link for some suggestions.
Diagnose Dan - Bmw e39 air suspension diagnose

https://www.youtube.com/watch?v=5w2JQPzXu0w

[sienayr]

Def check the sensor, I put mine on backwards after suspension overhaul (although I didn’t have the issues you are having, just SLS error on the dash)

[CPHES]

What I think is - your compressor is weak, and it was just keeping up until you emptied the system. I know, it’s just air, but he has to lift 1800+ lbs - in about 30 seconds if it is operating correctly. I’m guessing it was very noisy when all the air came out at disassembly. The clicking you heard makes me think he knows it is time to turn on.

[Olly84]

I was able to lift the car with 2 factory floor jacks that were able to get low enough on the ground, then jacked it back up on the diff. Checked sensors, they're ok and attached correctly (i don't have inpa so can't truly check if they're working...) . I jacked the car up to normal ride height, turned the car on and air compressor still did not turn on

I've researched the SLS computer modual itself rarely ever fails, but i took the comparment shelf off and had my rear tires in there with my tools, the likely hood of the weight of the tires in there wouldn't have squished the computer right? that'd make no sense.

I think the culprit is the compressor even though it looks completely pristine heh. I'm assuming the solenoids don't have anything to do with it because they only pass and hold air through left and right, they don't actually pump air right?

Going to the junkyard tomorrow morning to look at an X5 air pump, if not then I'll hit you up Danny to see what we can work out.

[CPHES]

Uh -here’s the catch 22 on that. If you made the car level, the compressor won’t run. All indications are a level car...

[Olly84]

No I jacked it up off the ground to lower than normal ride height and it still didn't do anything. Going to junk yard today to see if I can get an air pump assembly from an X5 from same era.

any idea how i test if it's a working unit or not on a junk car at the yard? =X

[rdl]

...
any idea how i test if it's a working unit or not on a junk car at the yard? =X

Have you tested to confirm that the compressor is faulty?

For diagnostic procedures try the link posted in post #13 above and this one
https://www.youtube.com/watch?v=M_VxT6h5bQE

I doubt you will be able to test at the wrecking yard. As I read it, the compressor module needs to be installed in a working car while connected to sensors, I-bus and other modules. I'd expect that a yard would give you some leeway to return it if it's inop when you try it out on your running car.
You can find wiring diagrams here
https://www.newtis.info/tisv2/a/en/
For instance, drilling down the menu, this diagram is for a 540IT with LWR (aim control module with HID/Xenon headlights.)
https://www.newtis.info/tisv2/a/en/e...l-unit/a9QdhsT
And this one, without HID/Xenon
https://www.newtis.info/tisv2/a/en/e...l-unit/a7Po5TZ

[Olly84]

thank you for that RDL.

I'm thinking it's the Air Compressor or the Ride Height sensors. I used a multimeter to test the electrical system of the SLS system and fuses and relays check out. Power is flowing through system except SLS compressor will not kick on. I don't want to manaully switch on the air compressor to test it since I've read that might cause a short in the system and turn off the SLS module itself.

Just purchased 2 ride height sensors from Amazon since they're so cheap to see if that will fix it, and hoping to get a used sls pump here as well.

[blackknight530i]

Posted this in the Touring section thread, but here it is here as well.

It's probably the compressor itself. I was having a similar issue after changing air bags and it was still sagging. One possible issue is a low battery, but more than likely it's the compressor itself. If it seizes up because of too much gunk/water/etc., It may try to work, but will stall out and quit.


I'm local and have a spare compressor I got from the salvage yard the other day from a X5 with SLS. It should work perfectly. You can try it if you want. Also, there is no truth to the compressor not working if the air is completely let out as I've done exactly that and it pumped right up.

[Olly84]

know what I never thought about it, but I tested my battery with a mulimeter today and it was severely low. 11.39 volts. I didn't even think about it since I figured once the car turned over the air pump would start from the car's power, not the battery.

[CPHES]

Agreed

[Olly84]

lugged the battery out of the wagon and dragged it up to my apt...chargin' it

[CPHES]

Agree with blackknight - a new / used compressor brought a completely empty system up in 30 seconds. A set of jumper cables brought it up in about a minute / jumper Needed due to main battery being dead. Don’t toss the old one / there are rebuild kits