Horrible noise from engine bay when accelerating

[Sam84]

Hi all

First post but long time browser, need help as i can't find this issue anywhere here.

First off thank you to all as some of these posts have pointed me in the right direction in the past (coolant leak, door actuator).

I have a Audi A4 2008 1.8 SE TFSI 6SP and last few days I got round to getting my AirCon sorted (still not sorted yet, but pressure sensor replaced at the front - still have a leak somewhere.) Also had a brake caliper and pads replaced at front.

Issue now is when accelerating I get a really loud noise from the engine bay, I want to say I think its turbo related but I'm a complete noobie with cars. So in first no noise, change to second and after 2 seconds of accelerating it sometimes kicks in, sometimes its in 3rd. If I drive carefully and don't punch it I can avoid it all together. I'll try and get a sound clip tomorrow but any possibles or guidance for simple checks greatly appreciated. At what RPM does the turbo kick in?

Also to add I have the common judder in 1st but I've learnt to deal with it until I can afford to replace the clutch/DMF but now I'm worrying that delaying this work has somehow damaged the gearbox

[Sam84]

Well to report back - while doing test drive with my trusted mechanic noise kicked in with clutch in while rolling to avoid idle limiter, the noise was there for 5-10 minutes of hard driving then suddenly out of nowhere it stopped, he believes its alternator bearing but for now its gone,