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A quick update..

Just purchased a floor jack last weekend. Going to buy the valve block and try to install once I receive it.

I noticed that the side affected occasionally makes a quick and loud hissing noise (about 2 sec long), and repeats a few times before it stops. The best I can tell it happens only on the back wheel and does not happen all the time. Could this still be related to having a bad valve block? The actual pump seems to work fine.

Oh, I also get a chassis error that only says I can keep driving normally but should have it looked at. I'm assuming it's related to right side of the car not being stable.

-David
Where does the hissing sound come from? You said it is the whole right side (passenger side) that drops down, yes? Is the hissing coming from the rear drivers side? That is where you would hear it if the valve(s) for the passenger side were releasing the pressure.

What kind of environmental conditions is the car in? Hot and dry or cold and humid? Is the car normally parked on a hill or slope?
 

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This hissing sounds like when you are filling a balloon and then let the air out all at once. Not like a slow leak, but a all at once leak (if that makes sense).

It's happening on the passenger side rear wheel.
The hissing only comes from the passenger side rear wheel, or that's the corner that drops when you hear the sound? Did you say the entire passenger side of the car drops down over night?

Also, do have any way of reading error codes? If the ride height sensor in that corner of the car is bad or producing bad data the Vehicle Dynamics Platform (VDP) may think that air strut is extended too far and try to release pressure erroneously.
 

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Last night I scanned for codes and got the following:

482974 VDP: Vehicle level - not adjustable
482963 VDP: Compressor relay - maximum switched-on period exceeded
483103 VDP: Vehicle extremely low - rear right
482953 VDP: Solenoid valve, pressure accumulator - maximum switched-on period exceeded
482936 VDP: Solenoid valve - rear right - maximum switched-on period exceeded

And like I mentioned in another post above, there are 4 to 5 bursts of air lasting ~2 seconds from the rear right wheel area after I turn off the car. I do not hear this from the front right wheel.

Does this still sound like it could be a valve block issue as suggested above?
As Robin750 mentioned- The first thing (and cheapest) is to check for leaks. I would spray soapy water on all the valve block connections, the air line at the rear passenger strut, and the two accumulator connections (at the accumulators if you can gain access to them). While looking at the valve block (before spraying it with soapy water) look at the electrical connections and you may even want to unplug all of them (one at a time) to make sure there is no water in the electrical connections and they look clean. You might need to clear an error or two if unplugging.

There is a very particular set of events that would have to happen (electrically) at the sane time to get the sudden release of air pressure out to atmosphere from one strut. For example, Three different solenoid valves all have to open at the same time- #1 Electrical solenoid valve for rear right air suspension strut (this one is normally closed and is in the valve block) #2 Electrical drain solenoid valve (this one is normally closed also, but is in the compressor body) and #3 Pneumatic discharge valve with pressure relief function (this is a pneumatically controlled valve controlled by #2, and is normally a flow control slow release, but when activated by #2, vents to atmosphere very quickly, also in the compressor body).

The only reason I could see the VDP causing this would be if it thinks that ride height sensor is fully extended, and tried to release pressure on that strut, but normally it would use the slow release to drain the pressure slowly, unless- the pressure sensor in the valve block is bad or has a bad electrical connection, and therefore can't verify the accumulator pressure. The compressor normally runs while driving and fills the accumulators (and can fill the struts directly), but when the car is off the compressor does not turn on unless the car is in the "Awake" condition when the car sees a remote and you see some message in the center display. When in this condition you might hear the compressor running if you put your ear near the rear drivers side wheel well.

I think you can look at the raw data from the ride height sensors using ISTA, but I have not tried that. Robin750 may know more about how to do that. I doubt the ride height sensor is the problem though, because you would have a similar air loss problem while driving.

You might also be able to see the data from the pressure sensor in the valve block somehow to see what the pressure is doing.

I also am not sure why (after the initial drop of the rear passenger side), the front passenger side would drop down slowly as well, since they don't share valves or air lines. Unless you park on a sideways slope maybe? Then the car would try to level itself and drain air out of that strut if the rear was already low.

This document has a good explanation of the air ride suspension starting on page 20-
 

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I watched a few videos and they access the strut tower screws through the rear speaker area. I was hoping I could do that in this case. Since I'm really new to ISTA, could you track me on how to find the repair info in the software?
So the dealer didn't fix the leak?

Click "Operations". Put in VIN number. Click "Open Operation" (bottom right corner). Click "Vehicle Management". Then, in "Repair / Maintainance"- "Product structure"
Click on #37 "Integrated Suspension Systems" on the "+" sign to expand it (left side).
Click on 3712 "Control and suspension elements, rear" (left side).
On the right side- click on "REP Removing and installing / replacing rear left or right air suspension strut

For the speaker (should be easier than pulling rear seat and shelf) click on #65 "Audio, navigation, information systems" in the same directory.
Click on "REP Removing and installing/replacing mid-range speaker" (this shows driver side, but same process for passenger side).

You should be able to do it buy pulling the speaker as you mentioned and slicing through the sound proofing (I would try that first). The videos I have seen are for the older F chassis, but German engineers think about stuff like that, so it should still line up well enough to get to the three studs / nuts on the air strut.

Either way, take lots of pictures and share with us.
 

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Thank you for everyone who helped me with this. I successfully changed out the right rear air shock on my 740. It was a very lengthy and slow process, mainly because I was worried that I would damage some of the interior during disassembly/reassembly. Luckily, that did not happen :)

A few issues I ran into:
1. The rear seat comes out very easily, but the back seat rest required 2 people. It sits on 3 hangers and is cumbersome to do it along. All the other interior parts came out and installed easily. I was very happy for this.
2. Installing the new air strut took 2-3 alone. You need a hydraulic jack to lift the new air strut into place. Some of the time was because I was being extra cautious and at that point I was tired. Also because the lower connection on the strut didn't line up perfectly with the wheel body (spindle?) fitting or was pushing up against it. I had to remove 1 bolt from the trailing arm to allow the wheel body to move out a tad.
3. The rear trailing arm did not align up on the wheel body. I had to twist the whole wheel body while someone else inserted the bolt.
4. Torqueing the strut to 240nm was a task. There wasn't much room and my torque wrench only goes to 204 nm. I did the best I could and plan on checking it in a month. If necessary, I was try and find a mechanic to check the torque as well.

Overall I am happy that I was able to complete the repair. It did take me 4 days (2 hrs, 5 hrs, 6 hrs, 8 hrs each day) but I saved roughly $2700 doing it myself. When the left side decides to go, then my time will hopefully be half.

:)
Awesome!
So there was no way to get to the the strut studs by just removing the speaker and cutting through the sound proofing?
 

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Honestly once I decided to follow the ISTA steps, I never really checked. The speaker cover on my car is narrow and there could be an issue getting a wrench to the strut nuts. It might be possible but probably higher chance of damaging the speaker molding. If I ever need to do this again, I could have the interior removed in 1 hr. It's really simple, minus needing help getting the back seat rest out, but worth it in not damaging the car.

Oh, one thing I noticed that was different than in the ISTA steps was it said remove the rear side airbags.. I never found those, even though there was "airbag" written on the C-pillar trim panel
Interesting. There was no cable attached to that C-pillar trim piece?
 

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They did allow me to bring my own aftermarket part. Previously they had said that they only install OEM and non used parts, but I asked nicely and they agreed. I guess the way they look at it, is money is money.
I got my letter in the mail last week. It looks like I could do the repair myself if needed, but if BMW covers it, I will not hesitate to let them fix it.
 

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Wow, that is a huge relief! I wasn't ready to spend the money on repair. I just threw it in comfort plus (that way it just kept filling the air while driving)

Another question I have is... Would I have to be the first/ Original owner to use the warranty or does it follow the car?
If you didn't get the letter and want it fixed now- the Service Bulletin is - SI B 01 05 22 (from May 9, 2022) shown here-
Give your BMW service center that number and you should be good (if the problem is a leaking strut).
If you bought the car from a private seller, BMW may not know you have the car.
 
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