I call bs, on how they sound. Just bad engineering! It doesn't have to become a problem for it to be bad, it's bad by design.
For example, my has been coming on pretty loudly - NOT ON COLD days, but on warm days or during longer drivers, it doesn't come on right away after the vehicle has been started so you know it has something to do with the engine being warm/hot etc.
On a 90 degree day you can hear it pretty loudly when putting foot on the accelerator. I'm sure if you go into a dealership and test drove a brand new one it will not sound like that. If this is true that they just sound like this then it would be making the noise every time, why would it only come on during certain times/condition?
I know there is no FIX for this, GM's BS regarding it being normal is a cop out way of saying we don't give a rats about it cause it's not going to kill anyone.