[Roman Martynenko]

It is minus 8 Celsius outside and my Ascent is making a continuous squeaking / whistling sound coming from engine compartment after cold start.
hard to find out exact source...
RPM is about 1700.
Is it a Turbo or the engine starts falling apart?
Here is the video:

New video by Roman Martynenko

photos.app.goo.gl

 

[Robert.Mauro]

Sounds kinda like an air leak through a valve or tiny opening, which could be the variable wastegate partially open (though ours generally sighs instead of whistles), or a pulley bearing, or an accessory. The other thing that can do this are the high pressure fuel injectors, meaning, they should quiet down when the engine warms up.

Alas, not the type of sound I'd think can be diagnosed with a video. If it's simply cold injectors being noisy, or the wastegate being set slightly open by the computer, nothing to worry about. If it's a bearing or air leak, then, of course, something needs fixing. Regardless, I wouldn't assume it's benign because it goes away when the engine warms up. If you can replicate it, I'd bring it in.