auto 160sri noise

[Unilateral]

Sounds like it's the noise a dodgy boost solenoid makes. It's the valve attached to the back of the slam panel under the bonnet

[Unilateral]

Nope, they show no fault. It's a common thing. 99.9% sure that's what it will be

[DeaniFLHT]

The solenoid valve gets gummed up and tends to stick.

The humming occurs when the valve is trying to release pressure from the turbo variable vane actuator, which is usually when off-throttle

Because the valve tends to be slow to move, the escaping air makes it vibrate like a reed. It might throw up an error, if the solenoid burns out.

If the valve sticks completely, you are more likely to see overboost warnings, or DPF regen failure.

[Lance]

It's a simple swap. Takes 2 mins tops.