My 2011 S80 t6 was experiencing engine overheating. The car was running fine but I was getting a engine hot warning at slow speeds. Everything worked fine when air was flowing at higher speeds. The car otherwise runs perfectly fine and there are no codes thrown.

Given the vehicle has 160,000 mi, I replaced the thermostat. The old thermostat came out in pieces so I know that it was bad.

Once installed the car seem to run normal on my test drive. The car sat for a few days and when I put some miles on it on a very hot day I was experiencing the same overheating but this time it had a rhythmic noise when the air conditioner was on.
The sound could be felt when I touched the turbo intake hose. It seemed to come from somewhere below that.

I've attached a sound file here
https://recorder.google.com/a6ad7a34-2d96-46fb-87b7-fefaa3235621

Any thoughts?