Faint Turbo Whistle

Hey guys,

A while back I put a new Darkside cartridge in my (Darkside) turbo and since then I can hear a very faint whistle from the engine when accelerating. It’s not loud at all and sounds very similar to the alternator noise you’d hear on an AM station. Doesn’t sound like a boost leak though I suppose that is possible. When I replaced the cartridge I replaced all o-rings in the intake system.

Should a turbo be completely silent or is a faint whistle expected? I don’t remember hearing one with the factory turbo.

Thanks!

Some claim to be able to hear it all the time, I only hear mine when I'm next to a barrier like a bridge parapet.
If it's a nice smooth whistle, I'd say you're good to go.

I didn't hear mine when I first installed it, however, I definitely hear it whirr. My transmission is louder, and to loud until third then I hear it.
I don't like the idea of a whistle, unless it's a tweet, like the little whistles you put water in, or the Jetsons mobile.
A whistle in a single high or low pitch tone is a boost leak.
Could have damaged an o-ring, or maybe double check the torque on the housing.

It might be my imagination but I think this has gotten louder with this cold weather. It seems to get fainter as the engine warms up.

Here it is after just starting the cold-soaked engine.

https://youtu.be/Z_lduHaGXBw

Three mechanics, one at a dealership, have expressed no concern over it.