2.5 d p38 wierd noise

I got a td p38 with a wierd noise, it sounds like a bus , you hear more turbo than anything else , sounds like a whistle instead of an old rattly diesel lol
I have been over all boost pipes and none leak , it has had another intercooler fitted ( cheap so thought I'd try it) just in case it had a hole or leak .
Any ideas on what to look at next ,
Hard to describe but for a good example as stated above it sounds like a bus or lorry pulling away and under load ,
turbo doesn't smoke ,truck pulls well , a little to well to be fair( maybe its been chipped in the past)
No mechanical problems
Could be belt related but it's just had another belt and all idlers and tentioners were checked

The BMW M51 Diesel was choosen as it is a little more refined then the more 'Agricultural' Oil Burners found in the Disco and Defenders....

It will sound like a diesel, just a bit smoother, and now you mention it If I listen to my DSE, I can hear a Turbo whine too, but I like that as it means it isn't siezed...!!!

The Turbo Whine shouldn't be excessive, there is a difference between a spinning turbine unit and the sound of a turbo not getting enough oil as the bearings start to squeal.....

The difference can be apparant....under lubed bearings is a squeal or screech where as a functioning Turbo will have distinct whine or whistle....

Can't really make out if it's Turbo wine or not , sounds more like a leak in boost but there isn't one, it's loud!
You can hear it outside easily and in the cabin it's really noticeable ,

defo sounds like a small leak then, as the Turbo Whine will only really be heard when accelrating under load....

A turbo leak will sound like a leaky air compressor (as that is all it is) mixed with the whine of the impeller disc.