Hi all havnt been on much l8ly an still new 2 this still trying 2 sus how site works but can any 1 help my turbo is making high pitch noise I no they whistle but this is different it's lot louder , it stil boosting around 11psi , I hav k&n filter on it standard apart from that and it's still only doing bout 23mpg on goin work an bak I do put me foot down now again but iv read some peoples post so I think it should b doin more , but the high pitch noise is a concern any ideas peeps 

Help pwease

Whistlin turbo can mean numerous things such as blown gasket in turbo, loose pipe or worst of all bearings in turbo gone, i would get it professionslly checked ASAP as if it goes you could actually kill the engine completely.