hello..some days ago i start hear a strange noise from air intake from 1 to 3 gear everything it's fine..but in 4 gear when pressing accelerator pedal or in 5 gear...not whistle sound...just like...like air filter it's wet..water pumping sound..i don't know how to explain..i have change vacuum hoses from boost control valve, air filter its new(clean). Power it's fine....turbo pressure 1.5 bar..how to check air intake, or all system it's fine..?? Thank you...

check your intercooler hoses as it might be that, if it is split normally the one that passes through inner wheel arch as it rubs against pipe eventually cutting through common stilo fault. It sounds like how mine started, eventually sounded like a Hoover. Need to get your hand up and feel pipe as it passes through arch ( get supply of disposable gloves as it can be really gungy)
Have a look at link below

https://www.fiatforum.com/showthread.php?t=152495

Unbalance turbine axle..