It was a VALVE related to the air conditioning that is in the rear left of the car. Was replaced 2 years ago but is now happening again.
Only when the temperature is over 90degrees, is very humid,...

Will try to repost clip.. It works at my swedespeed post "ForumFWD & AWD VolvosXC90 (2003-Current) Mystery sound ... has two local service shops stumped too"

AWD, 6 CYL INJECTION 3192 CC 240 HP,...

I have a 2013 xc90 and cannot figure out what the cause of this noise is.
Two service shops have also not ever heard it.
It happens whether AC is on and off, recirculate on and off, third row AC on...