I drive my XC60 T5 2018 now for a month.
It has a turbo right?
I am used hearing a light whistling sound whenever the turbo is activated on all my other cars.
This car doesn't do that. Does that mean it is not working or does the turbo on this car not produce any sound?

 

A perfect turbo in a well insulated engine compartment/car is almost silent.

It's when bearings/bushings get worn that turbos start whistling / whining and make noise. Eventually the fan blades/turbine wheels of the turbo start rubbing the intake or exhaust housing - then it's reallyloud.

 

From all my other cars I know the turbo makes a light whistling sound.

So the Volvo turbo is really silent then? I also guess that when the turbo is broken or not working some warning light will be illuminated, right?

 

You might get a check engine light if the turbo seizes, and have no power - but Turbo's rarely fail. Be happy it's quiet - a noisy turbo usually indicates lack of oil changes!

Pull the top cover of the engine off - (it just pulls straight up) note it's almost like a giant piece of sound absorbing soft styrofoam.