1.8T engine rattle

[KeithOT]

got a funny/nasty noise from the bonnet area use a heavy throttle 'off the line' get a tinny rattle, pull away gently through the same rev range no noise, try a heavy throttle in a high gear at low speed no noise - assume not pinking Knock sensors should stop pinking.
No fault codes - driving me nuts hear it with window open just hear it with closed windows.

 

[KeithOT]

got a funny/nasty noise from the bonnet area use a heavy throttle 'off the line' get a tinny rattle, pull away gently through the same rev range no noise, try a heavy throttle in a high gear at low speed no noise - assume not pinking Knock sensors should stop pinking.
No fault codes - driving me nuts hear it with window open just hear it with closed windows.

Local VW dealer found the problem loose exhaust manifold tightened it up noise gone!
Result!

 

[Snowflake]

Hi.

I'm having this strange sound from the engine when driving. I'm not to home with turbos so I need some tips. The sound appears when either changing gears (when letting the gas pedal go to slip in the next gear - manual box) or when accelerating and then letting the gas go.
The sound can be described almost like a bird twitter/tweeting rattle.
Own a mk1 Alahambra model 2000, 1.8T v20 AHJ