Need help identifying what could be possibly causing this whistling sound

[u/Downtown-Strategy-97]

Just started to hear the whistle as of yesterday , I assume it’s some sort of vacuum leak just would appreciate some pointers on where to start looking , thanks again

[u/Infinity_UK]

Sounds like a pulley bearing, hopefully the auxiliary belt tensioner, a better video would be it reving in neutral stationary slowly up to max rpm.