Wonder if the auto-wash put a glaze / funk on the rotors, from cold water & hot rotors ?

 

Little update on this, never could figure out what was maiking the noise, and now it's no longer doing it. LOL

 

Sometimes the belt will whine..trapped air in the ribs as it catches a pulley or belt getting hard...if not I'd be looking for a vacuum leak...one way to check belt is to soap it .. can spray it while running..lightly...works on the bike too