Bit Of Help Needed

[Wagsie]

OK so I did search around a bit but really didn't get any answers to what it is ?

Well on cold start up for about 10 Min's or so I Hear a tapping noise when on boost , it does sound like its coming from the turbo but as I'm a complete noob i really have no idea
After 10 Min's it goes away and I no longer hear it ?

Maybe the turbo on the way out ?

Any help would be cool
Thx
Wagsie