Is this an air suspension leak or...

[cab]

So I walked out into the garage a couple of hours ago and heard what sounded like an air hose leaking with a high pitched but relatively quiet whine (much different than the "normal" noises the car makes). At first I actually thought it was my garage compressor, but then I realized it was coming from my car. It sounds just like an air hose leak, but the suspension hasn't collapsed or anything (note: over the years it has done a few up/down dances). The high pitched whine almost sounds like the compressor (i.e. is there a tiny leak and the compressor is running to "keep up"), but it is quieter than I normally hear from the compressor (admittedly, I am usually inside the car).

Anyway, video below (hopefully you can get to it and hear it OK - it is most audible as I move above the tire and then beneath the car). Note there is no obvious leak at the strut air hose joint, etc.

Video of noise:
https://photos.app.goo.gl/sat5K9UVN9eWyP4P7


Car is a 2013 P85+.

Anyway, does this sound like an air suspension leak or something else?

 

[PWlakewood]

Does the suspension seem to be working ok? Any warnings on the dash?

 

[cab]

It does seem to be working OK (although I have not driven it) and there are no warnings on the dash. I just raised it to "very high" just to get a better view of the suspension components at it worked normally. I just looked up the location of the fuse boxes and pulled fuse 36 (air suspension) expecting the noise to stop and it did not...hmmmm.

Now I am wondering if it could be the vacuum pump.

 

[cab]

Well, just pulled the vacuum pump fuse and no change. Now I am thinking this is the coolant pump running (for hours) per this thread:
Continuous Faint Humming Noise When Parked