Hello! I have a ‘22 Tahoe Z71 Since opening my sunroof there has been a whistling noise that gets really loud & annoying. I have carried to the dealer who advised it was normal as it was due to the roof racks making the noise?? Funny it never did it for months after purchasing & driving. By chance anyone else heard of this?? I’m gonna take the roof racks off & test their theory this weekend. Thanks for any insist.
If it had racks on it before, and didn't make the noise, now it does, and the only "change" was opening the sun roof...it isn't the roof racks.
Inspect the sunroof, make sure there isn't a pinched seal somewhere or something.
Possibly open and lube the seals with silicone spray, to aid in the sealing and smoothness of closing.
Make sure the panel actually closed all the way by inspecting outside and in when closed.
Do as you are doing, but recognize that the roof racks could change the airflow and mitigate the whistle, but the panel still may not be fully closed.
Give it the water test: turn on a garden hose to a medium flow, open the sunshade inside but leave the panel closed, and irrigate around the seals while someone inside monitors for any water leakage...this will tell you if it is sealed or not...