2018 740e xDrive iPerformance
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.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.
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?