I have a new 2019 Silverado LTZ with 6.2L 10 speed transmission. I have a whining/supercharger noise that occurs at all times. It amplifies as the RPM'* go up. I thought it was the alternator but the dealership said it isn't the alternator. I only have 3k miles on my truck. Anyone have any idea as to what this noise is? I have driven other 2019'* and they don't do it.

Probably just turbine whine. The dealer couldn't tell you?

GM power steering pumps tend to whine.

The dealership said it was something coming from the transmission. Maybe some kind of pump

If it was the power steering, wouldn't it do it as you turn the wheel? Mine doesn't do it when you turn the wheel.

No.

If the dealer is 'having difficulty" trying to figure out where the noise is coming from, I suggest maybe taking it to another dealer.

If you can, disconnect the serpentine belt to isolate the power steering/alternator.

I agree. Take it elsewhere if the dealership can't figure it out. They should have taken the belt off to isolate the noise . . .

. . . and perhaps they already did.

So they said the noise is coming from the transmission? Then what? They gave it back to you and said "Mystery solved, now you know where that noise is coming from!" . . . ? Are they going to fix the noise?