Whistling Noise - TSI Engine ?

[A9X SJ]

I noticed this evening our car has developed a High Pitch Whistling Noise 

12 Plate Golf 1.4 TSI (122) Engine

Can anyone shed any light on what this may be does it on Idle and if I rev it

Only difference I have put Shell V-Power in it this week

[RocketRossUK]

A high pitch whistle can be a few things mate, from a simple air leak to problem with the turbo.

I would recommend getting someone to rev it for you and listen where is coming from.

One of the easiest fixes is to make sure all your air hose clamps and tight and fully snug in place. Then put your ear near the turbo and listen for the whistle noise.