Hello! I'm trying to figure out a loud whistle/siren sound that comes out of my defrost vents when going over 65 mph with my sunroof open or front windows down. With the windows closed its fine unless its a wind storm and then you hear little bursts. I posted a video a couple of months ago on youtube https://www.youtube.com/watch?v=mhHV_5LjIWQ I have searched and found nothing in the online forums. Tried changing the cabin filter but it didn't help. Any help would be highly appreciated. Thanks.
Oh I forgot to mention its a 2013 XC90

 

Wow, that's a new one. Should be under warranty though. Sounds like wind noise, possibly from the windshield seal.

 

Thanks ES6T, I was focused on the vents but it is possible it could be the windshield. Now if they hadn't recently closed Santa Barbara's Volvo dealer, this would probably already be fixed.

 

Is the blower fan on during this? Is the recirculation on or off? If it's on, I suppose it could be wind getting past the blend door. Hard to tell and I've never run across that before.

 

I have tried every setting possible and the only thing that greatly reduces it, is to hit the defrost button.