Strange whisling noise in engine

[sintek]

Hey there guys...
Steven here...VW Scirocco 2010 Mk3 dsg
So I have the strangest occurrence that can not be diagnosed by my local mechanic...
On start up a whistling sound can be heard...almost like a noisy fan belt, but not...
When revving it worsens...

If I switch off and restart a couple times the noise goes away and does not come back...
Initial thoughts were pcv unit which was replaced and not solved issue...

Any ideas from your side...

Thanks

[sintek]

Okay, so further investigation confirms...

Not the following...
-Pulleys or belts
-Roller on high pressure fuel pump
-PCV Valve

Cannot see anything wrong on turbo...

What else can I have looked at...It is driving me crazy...

[1.4_tsi]

Unfortunately, it's not really feasible to diagnose without hearing it and experiencing how it varies with engine speed, load, etc.

Have you considered the air conditioning pump? Does the sound change or go away with the a/c turned off?