How many of you guys have the whistle sound coming from your turbo ?

I sold a fault code reader to a young mechanic yesterday and he was saying that the bearings in my turbo where going and that was causing the whistling sound but that sound has been there for nearly two years and i have heard many other vectras and Saab 93 sound the exact same . My old mondeo had a whistle to and it is still flying with the same turbo. . The car is remapped to 150bhp from 120 pulls like a train no smoke running perfect but i do notice when i drive it hard i get what sounds like a dump-valve or an air release when changing gears that only happens when i boot it in low gears. I am a bit paranoid now about the whistle but the guy didn't even open the bonnet to check just said bearings i asked did he work on a cdti vectra he said no . when i went home and revved the engine the sound was coming from the turbo area.

To me the whistling is the norm for the vectra CDTI engine my turbo was also replaced at 79000miles so it says in the service book. personally i Don't think there is a problem with the car it is just that fiat multijet engine tone. the young mechanic just got me wondering.