I have a gremlin in my air suspension.( fixed😊)
 

I have the 2 axle suspension on my 2006 4.4i. I am having a odd problem.

1. Front end will lower to bottom end equally(no air in the front shocks.)
2. This can be in a couple of hours or may not occur for a couple of days.
3. It will lower evenly not one end or the other.
4. Rear stays in position.
5. When I activate it will raise front end with the reservoir or compressor to the correct position.
6. No faults or error message.
7. it basically operates as it should except for the front end lowering while parked.

I have the ista + and I have checked the following:

1. Raise and lower each shock. Works.
2. Check pressure, and tank for leaks works and correct.
3. Check level sensors , they work.
4. I checked every thing I could via ista+
5. I Removed cover and checked solenoid for leaks , none.
6. Check shocks and airlines for leaks , i could not find any.
7. I checked calibration and it is in range.

I thought if i had a leak in the shocks that one would lower, not both at the same rate. Both shocks were replaced by BMW with oem, 30,000 miles ago.
My x5 now has 83000 miles

I am stumped, anybody got any ideas??

I had this same problem. I ended up ditching the air suspension for coilovers, but in inpa I did note I had a front level sensor "offset" issue. As an aside my auto leveling headlights would not work properly either. As soon as I reset the offset issue my headlights worked. Not sure the two are related, but I wouldn't be surprised if the reset wouldn't have fixed the air ride too. In the end I was tied of dealing with it. :dunno:

Perhaps try the reset of the ride height sensors just for s's and g's?

I will try to reset the ride height sensors.
I will also run inpa instead of ISTA to get any other info.

It is baffling and is destroying my faith in this car. I would like just to find a broken part then replace it and go forward. This problem has been haunting me for a few months. Just in the last couple of weeks I was able to get a software set up to test it. ISTA does not show offset of sensors,not that I can find.

I can hear the air venting when I ask for a level change at the compressor. Is there a computer controlled exhaust valve at the compressor that could be malfunctioning also?

Gary

BTW, checking the sensors is done via one of the lighting modules. Can't remember if it's AHL, LKM, etc. But look in one of those modules. I had 3 offset values that made sense and one sensor's offset value was waaaaaay off.

I've read on the board that the offset value is important to reset when servicing the EHCII but as I said, I got tired of dealing with it and only reset the sensor after yanking the air gear while trying to fix my non-func auto leveling headlights. As soon as I reset the offsets the headlights worked again. Worth a shot for you anyway.

Latest is that the front has not gone down in the last three days.:nanana:

It did have a fault in the light level module that I cleared. It did not say what it was. I also reset the suspension module while on the ista.

The right front can be right on level or as much as a half an inch off. I think this may be a level sensor. I will check that tomorrow. Or maybe just order a new sensor.
So far crossing my fingers that it at least stays up.

3 days is a good sign. Hope the reset is all it needed. :thumbup:

I'm pretty sure that's all mine needed but I was so frustrated one night I threw in the towel and ordered coilovers. This was before I got inpa and associated suite running so had never been able to reset the level sensors or the ehc2 module. Oh well. :dunno:

Car still has a gremlin. The car sat in the garage for 4 days without lowering. I backed it out straight into my driveway and within an hour the front air shocks emptied.��

I am stumped. Soaped up the bags and no leaks. If I changed out the bags this would be the second time they have been replaced. Once at 50000 miles an now at 83000 miles. Too much?
I am Beginning to think coilovers may be in the future.

Sounds like the proportioning valve or the actual air fittings that connect to the bags, if you’re not getting anything from the bags themselves. Not I don’t have front air, but I have chased a sagging rear back to a loose fitting at the reservoir.


Sent from my iPhone using Xoutpost.com

Were you able to find an "offset" value for the ride height sensors? Are they all reporting normal values? I had one that was just bonkers (-200 something) and 3 that were fine. I replaced that one sensor (left front) and no change. Later, after ditching the air suspension, I was playing with INPA and found the offset counter. Reset it and voila all the sensors were reporting plausible values. And, as a side benefit my auto aim/level headlights began working again after not working for 2 years. Could be coincidence, but the way all these modules work together, I think this sensor reading had something to do with my front bags deflating. I have read mention of it in other past threads here as well.

Good luck, keep us all updated.

Edit: Here's a link to a good thread about ride height calibrations. Much of it pertains to lowering the stance via calculations but it will also tell you how to zero out the suspension again.

https://xoutpost.com/bmw-sav-forums/...ration-17.html

Checked all the fittings at bags and proportioning valve with soap ,no leaks.

I was thinking the proportional valve or there are a couple of selonoid valves on the pump also.

I wonder if these are serviceable?

Level sensors are all around 2.5 volts when level. I set the 0 level so all points are within 5 mm. I do not have any wild offsets either.

Headlight levelers are working and no fault there also.

I do have a fault in the Ike module but I cannot tell what it is, it-functions as it should.

Just really weird that car can stay level for a few days then move it and the front end goes down. Or other days drive it for a while and it stays up 4 out of 5 times.

:dunno::dunno:

That's good then. If all the sensors and offsets are reading correctly you have a hardware issue.

Have you checked the proportioning valve and lines at the big air tank under the truck for leaks? There is front/rear distribution on that solenoid and a gasket material between.

This tank and the solenoid (I have 2 because I was chasing my issue :():

https://i.postimg.cc/xTr730QD/Air-Su...n-Repair-1.jpg

I did take the bottom panel off and soaped all fittings on the tank and proportioning valve no leaks. When i did the ista test it checked all functions of the valve, tank, compressor, sensors etc. They where working.

I am not sure if there is an exhaust valve on the pump itself. my next step is to get at the pump and verify that nothing is leaking in there. pump does get up to 15.5 bar so it is working properly. No water leaks in spare tire compartment.

It is so intermittent that is is hard to locate the problem. Maybe a sticking solenoid. This is why i am wondering if the proportioning valve is serviceable.

I disassembled one of mine. It is "serviceable." I don't your find individualparts (I couldn't when I tried), but it was easy enough to take apart and reassemble so a fix could probably be improvised.

I went through this same song and dance for a month or so. :dunno: :rolleyes:

When you took you valve apart could you see any evidence of sticking or leaks?

I did not. And since I had the same results with both valves and tanks I moved on in my diagnosis and ruled out those components as the problem. :dunno:

I do miss my air suspension's functionality, but I do not miss the headaches. At all.

:iagree: There are many other things to worry about on this car. I would like to drop the air suspension off my list.

Suspension is fixed!! Seems that it was a leaking airbag after all. The reason it was intermittent was the height of the car would put the airbag roll in a position that it would leak. Slow leak just at the fold. When not in position it would hold air.
It was being particularly bad one day so I rechecked the bag with soap and water and found it.
I replaced both air struts and now the car is good. Odd thing is this is the second time the bags had been replaced . Once under warranty at 52000 miles and now at 82000 miles.

I am just ecstatic that it is fixed �� !