Puzzling Air Suspension Issue

[wesbos]

When I lock it and come back, it turns on, lifts the car up and kicks off. Thankfully it's not constantly running.

Pretty sure when it's initially down, the compressor isn't on. I have the bottom cover off still so I'll try and put my hand on it next time to see if it's running.

[wesbos]

Just an update for anyone who finds this thread in the future.

I swapped out the 5amp fuse 2 days ago. It wasn't blown, but the prongs on it didn't look good - sort of cloudy / got hot.

Day 1, it didn't drop but it threw the raise time control code.
Day 2, it didn't drop or throw a code.

Will see what happens today. Might even replace the balls in the compressor once more if this fixes it...

[scotty339]

Hope for the best. The fuse could of been causing power voltage and draw issues... cant hurt. 5Ah is relatively low, but over time can see some wear.

Just hit 100K KM on mine, I've already replaced the rear bags and before this winter I think I'll do my tune up and change the desiccant in the compressor. Good idea.

[wesbos]

yeah we replaced our bags at 100k as well. If you are near Hamilton I've got lots of extra desiccant.

Just an update for my own log

Day 3 it didn't drop, but threw a code where it would not raise on the rear right. I was parked on a slant and when I moved to level ground, it leveled itself back. So that was weird, but it seems everything was working as expected.

Day 4 no drop, no code.

[wesbos]

Had someone email me about this thread, so I thought I'd compile all my info on the fix:

1. I took the compressor out and replaced the desiccant balls inside. this is the video showing how to do that:

a. Jack up the car from the front - there is a jacking point with 2 holes. I used a hockey puck between the jack and the foam panel. Put jack stands on each side
b. remove the panel covering the compressor
c. I used a 10mm to slowly let the air out of the lines, was pretty easy. If you have ISTA-D software apparently you can do it this way.
d. Pop the compressor out - there are 3 or 4 bolts and 3 connector wires. No need to take the compressor out of the housing like they did in the video. Just take the whole cage out.
e. Open it up like the video, replace the balls and dry it well. You can even let the balls dry out in the sun if you don't want to buy new ones.

2. I swapped the 5amp fuses in the back - they were not blown but did look like they had been under heat load.

It did not immediately fix the problem, but after I swapped the 5 amp fuses, it never happened again - it's been about 2 months. I imagine there was also water in the compressor lines or something that needed to clear out. Ours was SOAKED.

I left the panel cover off for about 3 weeks, each time I started the car, I'd put my hand on or listen for the compressor. Each time it would run for a shorter time and then shut off.

I also used the BimmerLink to clear any codes that popped up.

Another thing I'd suggest that I didn't do is replace the "bmw green yellow relay" in the back fuse box. It might not be your problem, but cheap to rule it out.

Hope that helps! Here are some photos from the journey:

View post on imgur.com

[scotty339]

Glad you got it all sorted out!

[msd3075]

Originally Posted by wesbos

Had someone email me about this thread, so I thought I'd compile all my info on the fix:

1. I took the compressor out and replaced the desiccant balls inside. this is the video showing how to do that:

a. Jack up the car from the front - there is a jacking point with 2 holes. I used a hockey puck between the jack and the foam panel. Put jack stands on each side
b. remove the panel covering the compressor
c. I used a 10mm to slowly let the air out of the lines, was pretty easy. If you have ISTA-D software apparently you can do it this way.
d. Pop the compressor out - there are 3 or 4 bolts and 3 connector wires. No need to take the compressor out of the housing like they did in the video. Just take the whole cage out.
e. Open it up like the video, replace the balls and dry it well. You can even let the balls dry out in the sun if you don't want to buy new ones.

2. I swapped the 5amp fuses in the back - they were not blown but did look like they had been under heat load.

It did not immediately fix the problem, but after I swapped the 5 amp fuses, it never happened again - it's been about 2 months. I imagine there was also water in the compressor lines or something that needed to clear out. Ours was SOAKED.

I left the panel cover off for about 3 weeks, each time I started the car, I'd put my hand on or listen for the compressor. Each time it would run for a shorter time and then shut off.

I also used the BimmerLink to clear any codes that popped up.

Another thing I'd suggest that I didn't do is replace the "bmw green yellow relay" in the back fuse box. It might not be your problem, but cheap to rule it out.

Hope that helps! Here are some photos from the journey:

View post on imgur.com

I've been having the exact same issue as you've experienced and have been searching for a solution for a week or so now. The rear suspension will be absolutely fine with no sagging, and after start-up the rear suspension will randomly just release all the air pressure within the first few minutes after start-up. It'll re-inflate after you let the car sit locked for a few minutes, but the issue is that now it won't inflate back up.

I changed the humidity beads this morning (they were in bad shape with noticeable moisture in the canister), but the system still won't inflate. When I unlock the car and open the door, the compressor will turn on for a minute or two on it's own but then shut off with no results. I turned the car off and then slowly undid the red/blue air lines, and both bled a bit of pressure but nothing significant at all. I also pulled the larger black hose off while the compressor was running, and I didn't feel any pressure being released.

Both airbags have been replaced within the last year (<10K miles), so I'm pretty sure they aren't the issue. The fact that the compressor is turning on all by itself makes me think that the control module and sensors are also working fine.

Either there is a major leak in the system (which I doubt because both bags are fairly new and haven't had sagging issues typical of prior to a major leak), the compressor is bad (it is running but might not be making enough pressure), or a valve in the valve block is stuck open.

Anyone have anything similar to this happen to them?

[msd3075]

Originally Posted by msd3075

I've been having the exact same issue as you've experienced and have been searching for a solution for a week or so now. The rear suspension will be absolutely fine with no sagging, and after start-up the rear suspension will randomly just release all the air pressure within the first few minutes after start-up. It'll re-inflate after you let the car sit locked for a few minutes, but the issue is that now it won't inflate back up.

I changed the humidity beads this morning (they were in bad shape with noticeable moisture in the canister), but the system still won't inflate. When I unlock the car and open the door, the compressor will turn on for a minute or two on it's own but then shut off with no results. I turned the car off and then slowly undid the red/blue air lines, and both bled a bit of pressure but nothing significant at all. I also pulled the larger black hose off while the compressor was running, and I didn't feel any pressure being released.

Both airbags have been replaced within the last year (<10K miles), so I'm pretty sure they aren't the issue. The fact that the compressor is turning on all by itself makes me think that the control module and sensors are also working fine.

Either there is a major leak in the system (which I doubt because both bags are fairly new and haven't had sagging issues typical of prior to a major leak), the compressor is bad (it is running but might not be making enough pressure), or a valve in the valve block is stuck open.

Anyone have anything similar to this happen to them?

Finally solved this suspension issue that sounds identical to that of the original post. The culprit was a corroded pressure valve located on the black cylinder piece that's a part of the air compressor unit. It's directly inline with decadent beads, so it looks like humidity/moisture from the bad decadent beads caused the corrosion.

It took a huge amount of force to remove the valve. When it finally did pop out, the metal shaft was seized inside the valve, pretty much making the valve stuck wide open. I unseized the center metal shaft and cleaned everything up enough to where it could freely move again. Put everything back together again, and now it works perfectly.

I've attached a pic showing the location of the valve as wells as a pic of the corrosion on the valve after I worked the shaft out but before I cleaned it all up.

Hopefully this helps everyone out if/when they have this same problem.

[F15_SGM]

Hi guys I'm having same issue and warning on I drive it started after the recent snow storm. I had changed bags to arnott a couple months ago. Both sides will go down and chassis restricted light will come on. After I shut car and re unlock it will be fine. Can anyone please help me. I'm quite worried. Also the valve that's posted on this fourm where can I purchase that part from? Thanks

[Venturer500]

Originally Posted by msd3075

Finally solved this suspension issue that sounds identical to that of the original post. The culprit was a corroded pressure valve located on the black cylinder piece that's a part of the air compressor unit. It's directly inline with decadent beads, so it looks like humidity/moisture from the bad decadent beads caused the corrosion.

It took a huge amount of force to remove the valve. When it finally did pop out, the metal shaft was seized inside the valve, pretty much making the valve stuck wide open. I unseized the center metal shaft and cleaned everything up enough to where it could freely move again. Put everything back together again, and now it works perfectly.

I've attached a pic showing the location of the valve as wells as a pic of the corrosion on the valve after I worked the shaft out but before I cleaned it all up.

Hopefully this helps everyone out if/when they have this same problem.

I have the same history with one bag deflating overnight (had the rear left bag replaced twice last year in May and July under warranty with BMW Dealership) which has now developed into both bags collapsing after starting the vehicle yesterday morning (warranty now expired). If I buy the bags and compressor myself do I need ISTA to inflate them or did yours go up from flat just sitting on the ground?

[tlow98]

Originally Posted by Venturer500

I have the same history with one bag deflating overnight (had the rear left bag replaced twice last year in May and July under warranty with BMW Dealership) which has now developed into both bags collapsing after starting the vehicle yesterday morning (warranty now expired). If I buy the bags and compressor myself do I need ISTA to inflate them or did yours go up from flat just sitting on the ground?

You should not need ISTA - I recently removed and serviced my pump and replaced my air bags without ISTA.

I just plugged it all in and turned the car on afterward. it pumped up no issues.

Just be sure and unplug the battery before you start all of this.

[Venturer500]

Originally Posted by tlow98

You should not need ISTA - I recently removed and serviced my pump and replaced my air bags without ISTA.

I just plugged it all in and turned the car on afterward. it pumped up no issues.

Just be sure and unplug the battery before you start all of this.

I've serviced the compressor now but have not replaced either bag yet. Good pressure coming from the compressor into the little distribution box that the red and blue pipes connect to but the pressure coming out of that distribution box doesn't seem very strong. I'd like to jack up the car at the rear and to take the weight off the bags before they pump up but the self-levelling sensors won't let the compressor activate when it's jacked up because they are happy with the ride height. I find it hard to imagine the left bag being punctured or faulty given that it was replaced twice last year though. I've sprayed soapy water on the bags while the compressor is on and got no bubbles. It's great that this system is small, self contained and isolated from the rest of the car - the system itself seems so simple, just so frustrating trying to find the fault. Anyone have any thought or experience on whether both bags could have ruptured when it sat down on the driveway or should I just take a chance on buying a compressor first? It hasn't driven anywhere since it sat down so no trauma to the bags.

[tlow98]

Originally Posted by Venturer500

I've serviced the compressor now but have not replaced either bag yet. Good pressure coming from the compressor into the little distribution box that the red and blue pipes connect to but the pressure coming out of that distribution box doesn't seem very strong. I'd like to jack up the car at the rear and to take the weight off the bags before they pump up but the self-levelling sensors won't let the compressor activate when it's jacked up because they are happy with the ride height. I find it hard to imagine the left bag being punctured or faulty given that it was replaced twice last year though. I've sprayed soapy water on the bags while the compressor is on and got no bubbles. It's great that this system is small, self contained and isolated from the rest of the car - the system itself seems so simple, just so frustrating trying to find the fault. Anyone have any thought or experience on whether both bags could have ruptured when it sat down on the driveway or should I just take a chance on buying a compressor first? It hasn't driven anywhere since it sat down so no trauma to the bags.

Good info. Did you take apart the valve when you were servicing the compressor as in post 30 from this thread? I didn't need to do that but based on what you're mentioning that seems like a logical step. Also, change out the desiccant beads.

Also, to get the compressor to initiate I put a jack on the rear pumpkin and lowered it enough that the wheels were on the ground and the entire rear was low enough to initiate the air flow. I just didn't lower it all the way so as to damage the suspension or fenders. Hope that makes sense.

[Venturer500]

Originally Posted by tlow98

Good info. Did you take apart the valve when you were servicing the compressor as in post 30 from this thread? I didn't need to do that but based on what you're mentioning that seems like a logical step. Also, change out the desiccant beads.

Also, to get the compressor to initiate I put a jack on the rear pumpkin and lowered it enough that the wheels were on the ground and the entire rear was low enough to initiate the air flow. I just didn't lower it all the way so as to damage the suspension or fenders. Hope that makes sense.

Thanks. Have my issue sorted now. Problem was with the solenoid valve attached to the compressor unit. It was very tight as per the previous post with photos. I cleaned that up and used a bit of very fine sandpaper on it.

In my case the main issue was actually with the little rubber o-ring on the top of the male rod in that valve. It was sticking and coming away from the valve when the valve closed which allowed air to leak. I replaced that o-ring and the problem was solved. I also received a replacement solenoid from Amazon today in case of future issues (the one in the photo is the new one). I'll keep the replacement safe in case if future issues but for now the reconditioned unit is fine. This valve works magnetically.

Dessicant beads were totally dry in mine but that could be due to the Irish weather being quite dry and hot at the moment too.

Plenty of power in the compressor to inflate the bags from the ground up without a ramp or even a jack. If you find that the two sides are not level then there is adjustment on the self levelling sensors which are easily visible and accessible if you lie in underneath the back bumper. A size 8 spanner will loosen the nut and then, as you move the sensor slightly, you will hear the compressor either activating to increase pressure or purging air to drop the height. Slight adjustments and measure until you're happy (mine is good at 32 inches).

Main thing is, don't panic and don't run to your main dealer straight away (like I did). It is repairable. The great thing is that the air suspension system is a standalone system that doesn't appear to produce any fault codes - great news for DIY repairers like me who don't have the software to deal with those kind of faults.

[tlow98]

Nice happy to hear this! More info for everyone.

[spit]

Originally Posted by Venturer500

Thanks. Have my issue sorted now. Problem was with the solenoid valve attached to the compressor unit. It was very tight as per the previous post with photos. I cleaned that up and used a bit of very fine sandpaper on it.

In my case the main issue was actually with the little rubber o-ring on the top of the male rod in that valve. It was sticking and coming away from the valve when the valve closed which allowed air to leak. I replaced that o-ring and the problem was solved. I also received a replacement solenoid from Amazon today in case of future issues (the one in the photo is the new one). I'll keep the replacement safe in case if future issues but for now the reconditioned unit is fine. This valve works magnetically.

Dessicant beads were totally dry in mine but that could be due to the Irish weather being quite dry and hot at the moment too.

Plenty of power in the compressor to inflate the bags from the ground up without a ramp or even a jack. If you find that the two sides are not level then there is adjustment on the self levelling sensors which are easily visible and accessible if you lie in underneath the back bumper. A size 8 spanner will loosen the nut and then, as you move the sensor slightly, you will hear the compressor either activating to increase pressure or purging air to drop the height. Slight adjustments and measure until you're happy (mine is good at 32 inches).

Main thing is, don't panic and don't run to your main dealer straight away (like I did). It is repairable. The great thing is that the air suspension system is a standalone system that doesn't appear to produce any fault codes - great news for DIY repairers like me who don't have the software to deal with those kind of faults.

could you provide a parts number solenoid valve which did you buy on amazon? or post a link

I am looking, but I did not find anything for F15

[mweaver]

What desiccant beads does everyone use for this? The video quotes 1-3 mm blue silica beads on Amazon, but I can't find them. Anyone have a link?
Or do the 2-4mm beads also work?

Thanks!

[RED_Y_]

I think this is the original link https://www.amazon.com/gp/product/B01G5NTE8E/
but you can find something similar.

[mattingamells]

I’ve read a lot of posts where folks stated that they could get their compressor to switch on by unlocking their car. Mine only comes on when I start the engine…is this normal or an indication that something is wrong with the system (relay, fuse, compressor itself)?

I recently had the bags replaces with Arnotts but passenger side is always down in the morning so thinking there’s something else amiss but it’s always puzzled me when I read others could unlock their cars to get the compressor to inflate the bags if sagging.

Thanks in advance.

[arrenredd]

How were you able to open it? Did you use any tools?

Originally Posted by msd3075

Finally solved this suspension issue that sounds identical to that of the original post. The culprit was a corroded pressure valve located on the black cylinder piece that's a part of the air compressor unit. It's directly inline with decadent beads, so it looks like humidity/moisture from the bad decadent beads caused the corrosion.

It took a huge amount of force to remove the valve. When it finally did pop out, the metal shaft was seized inside the valve, pretty much making the valve stuck wide open. I unseized the center metal shaft and cleaned everything up enough to where it could freely move again. Put everything back together again, and now it works perfectly.

I've attached a pic showing the location of the valve as wells as a pic of the corrosion on the valve after I worked the shaft out but before I cleaned it all up.

Hopefully this helps everyone out if/when they have this same problem.

[RED_Y_]

Originally Posted by arrenredd

How were you able to open it? Did you use any tools?

You will need a torx to remove two bolts holding the valve, seems to be pretty clear from the picture above.

[aschmidt]

Guys, overnight got rear sagged, not able to hear any noise from compressor when I unlock the car or start the engine. What's the best steps to start diagnosing the issue? air bags visually are ok, both sides just went down overnight. F15 2017 xDrive35i with 45k miles on it. Thanks in advance. Checked ISTA+ no error codes. Should I start with fuse, then soapy water then get to compressor? I tried compressor test via ISTA+ but rear doesn't seem to move. Is it clogged lines or compressor?