Air Suspension leaks overnight: No error messages

[FortyPlus]

Hi all
I have a 2016 Q7 4M, 50k miles, air suspension.

The past 2 mornings the Q7 has been fully lowered when in the morning: I assume air suspension leaked. When I turn on the ignition, I can hear the compressor turn on and it raises to normal height pretty quickly: maybe 60 seconds, then the compressor turns off.
After an initial error saying the car is too low to drive which clears almost immediately on raising, there is no displayed error.

If I leave the car parked all day it appears to maintain the height, so thus probably a slow leak somewhere. There is no recurring error message, and a scan with VCDS does not reveal any error.

A search of this forum does not reveal significant Air Suspension errors other than a few compressor replacements.
Other than a trek to the dealer, any thought on how to diagnose the issue. I usually like to have the issue figured out before I go to the dealer, just to be on the safe side

I did see one reference to a kit to cure a known air suspension leak that could arise close to the compressor?

Before the Q7 I did have 2 x VW Phaeton for around 10 years and several hundred thousand miles covered with a similar air suspension system without issue, so happy enough with how the system runs.

Thanks!

[valewood]

Had a problem with the air suspension on my 2017 SQ7 last year. The Audi Tech who attended, before it went to garage, diagnosed a hole in the air pipe due to it rubbing on the chassis. He had seen a few so it is a known fault. Suspect you might have the same ,although mine did bring on a suspension fault light.

[FortyPlus]

Had a problem with the air suspension on my 2017 SQ7 last year. The Audi Tech who attended, before it went to garage, diagnosed a hole in the air pipe due to it rubbing on the chassis. He had seen a few so it is a known fault. Suspect you might have the same ,although mine did bring on a suspension fault light.

Thanks for that, yes, it seems to be a known issue. I found this Audi TSB that describes it.

I should clarify, I did get a "car too low to drive" or similar message, but it cleared as soon as the car rises: around 90 seconds from ignition on, with no residual error.
And initially, no error in VCDS scan, but I will double check that.

https://static.nhtsa.gov/odi/tsbs/20...73851-0001.pdf