New (to me) 2006 4.8is with some air suspension issues

[SlickGT1]

Originally Posted by RedsoX5

Mine had same issues in addition to a negative ride height reading on front left.

All fixed with new front struts and rebuilt compressor. Main issue was front left sensor installed incorrectly. Flipped around so read negative. For some reason BMW dealer could not fix for PO.

Absolutely perfect now. Thanks to all for input in different post!

Is your issue fixed? Where are you in Florida? I go to Bradenton area often to visit family. Peace.

Can you explain by what you mean it was flipped. As in facing the wrong way, or were the arms turned over 360 to the wrong side?

I keep having this front left random sag, and my reading is also negative. How the hell does it still function?

[Awntchi]

SlickGT1, this happened to me also. The sensor arm has to be facing up...like an upside down L (7). Mine was completely off and hanging in the air when I noticed it, put it back facing down and the car wouldnt raise up, turned it around and hey presto!

Good luck!

[SlickGT1]

WTF. Ok, I will check again. Mine goes up and down. Just always reads negative on that corner.

Any tricks one removing the arm from the sensor? Does it just pop off?

[Awntchi]

It is a ball joint, should pop off with some care. Pay attention to the edges of the plastic though, if the gets too worn out from trying to pop it off then it wont stay there long once you put it back.

PS. Look at the other sensor for directions, you should have one on the other side.

[SlickGT1]

I thought I did, both look like they should, well mirrored.

Strange.

[Awntchi]

When it comes to ride height, having the car stay at operational height, the sensors and airbags must be fully functional. No leaks from airbags and sensors intact.

The car will always lower itself if not driven for a few days, goes in to sleep mode if you like. It should however raise itself up by just unlocking with the key, the air stored in the reservoir tank will be released into the airbags, returning the car back to normal height. The compressor will kick in once the car is started, to top up the reservoirs. If you drive the car regularly and it still lowers itself or doesnt go up evenly then the airbags or sensors are the problem.

Feel the airbag by hand and see if it's empty (soft), if so then it's leaking and should be replaced. If it is hard even though it's lowered then the sensor is faulty (or loose).

Also, feel the air hose connected to the airbag (the connection point), it could be leaking from there also.

I'll try and take a pic of my sensor so you can compare....just in case.

[SlickGT1]

Yea, that is the thing. I have records from my car from the dealer since new, this is before I got it. That side airbag was replaced a million times. I have new Arnots in there. The bag feels hard, maybe not as hard as the other side, but hard.

It might not be hard enough because the car is literally lowering it.

My pressure at the compressor is 17psi.
I can raise and lower it no problem, and it seems to go normal maxed out height, and will actually lower itself back down close to normal when it goes back to normal mode. But somewhere while driving it, it lowers another centimeter or so, and stays that way. It drives fine, but I just can't seem to get it to stay at normal height no matter how many times I adjust it via software.

It will only pick itself back up, if it is too low. It will stay in that lower-ish stance indefinitely. As in won't go lower when not driven. And won't got up when driven either. Its like it thinks that is the normal height.

I don't want to throw parts at it, so I'm trying to really pinpoint it. My arnot bag might be leaking, but they have lifetime warranty, so I can always switch it. I just can't find a leak. Did the soap water thing, all over the place, nothing. My compressor also not kicking in all the time like when you have a leak.

And again, that front left bag was replaced 3 times by the dealer, before I got the car.

Another question, that sensor arm, should it look like a (7) when looking at it from the behind the steering wheel, as in looking toward the front of the car?

[Awntchi]

Yes, the (7) shape should be seen from front and back. Judging from your explanation, it seems the bag is fine and not leaking. For as long as it's not soft and does not bottom out then you're good (when mine was faulty and bottomed out I could not turn on full lock as the tires hit the bags and inside wheel arch).

I'd say it's most likely the sensor, all sensors have a pre-programmed ride height....I'm not sure what that is but it could be possible that the sensors are set on different levels....? Sometimes they start acting up due to a rim size change also, my car doesn't like the winter rims (19s) and takes a moment until it readjusts the height to suit them.

I have taken the pic of my sensor but I don't know how to attach it, I don't have a "URL link" for it....it's in my hard drive :/ Do you know how this works?

[SlickGT1]

Don't use the quick reply feature, but go advanced. You will see a paperclip icon. Attach your image directly to the site.

On a side note. Today, I opened up my trunk before leaving and guess what, the car lifted, and went to normal height. WTF?

[Awntchi]

Ok, attached now. Thanks!

You seem to definitely have a sensor issue, the car does adapt depending on cargo weight (towing etc)....not saying that you put weight but the sensor must be loose or simply faulty if it reacted to the trunk opening.