AGBoswell

I have a 2005 Audi S4 avant tiptronic and every time I start from cold it makes a load high pitch noise which goes away after about 10 seconds. Then when driving there’s a different whining noise that sounds like a belt rubbing against something or like a turbo charger. It gets loader the higher you rev even in neutral. This has been going on for about a year. It seems to almost go away completely when the car is very hot. Audi seems to think it’s coming from the gearbox which has been giving me a few problems for a long time, like knocking into 2nd from 3rd gear and 6th - 5th gear when very hot. ZF doesn’t seem to think it’s the gearbox but can’t be sure without removing the box and putting it onto a Quattro test bench. I can send videos of the noises but they quite big files. Please send me any comments. Thanks