Weird noise

[tiptron]

So I have a interesting noise that happens after i let off the gas pedal from a high rev, sounds like a fan is grinding on something. Its not to loud but its noticable to me. It also only happens when the car is in drive not neutral or park. This starting happening after i changed the airfilter so i have no idea whats goin on. Any wisdom would be great thanks

[Insane_Audi]

could be a transmission bearing..don't know how auto transmissions work

[tiptron]

Nevermind I took it to my audi guy and right away he said its a bad diverter valve.

[b7a4GT30]

dont mean to thread jack but im having a weird noise too. When flooring my car and it gets towards 5k it starts making a huge whoosh sound (sounds like either theres a massive boost leak or the air intake is sucking in air). Care is bone stock except for mods in the sig. Any ideas?