Turbo questions

[55tdi]

Hey. My 2006 MK5 A5 Jetta has developed a real whistling noise just prior to the turbo coming on . Have tried to research the cause and looking for anyone that has experience this problem. The car seems to run fine but the noise really bugs me

 

[Seatman]

Could be a tiny boost leak, does the boost feel later than usual or anything like that?