Freelander 2 2.2 diesel whistling sound

I have a freelander 2 once I start driving I can hear a whistling sound it's not coming from the turbo I just can't pin point it land rover said it was the intercooler which they replaced but it's still the same the car drives OK but it's really irritating there are no codes coming up any ideas cheers

Why would they replace something that isn't causing the issue? Has the throttle body been checked, just incase the butterfly is stuck at a mid point?
Have all boost pipes being checked? There are 4 rubber sections, and the solid sections can rust through (under the engine), or wear through (across the lower radiator).
The turbo itself can be heard, at some boost levels/engine speeds.