What actually causes a whine to occur?

Alternator died, and car went into limp mode. Had to jump it and crawl back home. Steering was fine. Next day after nee alternator installed, the steering was stifffffff. Could not move it. May have been from me disconnecting one of the PS hoses to make space.

im guessing the damage happened during limp mode, where the lack of belt movement but using the steering did something. Now I get a whine that rises with RPMs. Almost like a supercharger whine.

-replaced the pump o-rings 3 months ago.

-replaced the fluid yesterday, whine still occurs

-no bubbling in the reservoir (so no air leak)

anyone know what exactly causes whine, and if it can be fixed diy like so https://acurazine.com/forums/3g-tl-2004-2008-93/why-you-should-rebuild-your-power-steering-pump-938470/

 

I had a similar super charger like whine and it turned out to be my serpentine belt tensioner.

 

Perhaps, as a result of disconnecting one of the P/S hoses, air was introduced into the system?

Did you bleed the P/S system of air when everything was put back together & topping off the fluid?
Refer to step #8 below:

 

What did you do fix this? Just change the belt or?

And as for potential air in the system, I did bleed it yesterday when i changed the fluid. But still a little stiff when stopped and still have the whiny sound, but only prevalent at 3k and higher RPM

 

whenever it whine, it would be wise to rebuilt the pump with fresh seals and bearing. As soon mine whine, I rebuilt it and boom the whine goes quite.

 

https://acurazine.com/forums/2g-tl-1...-whine-968753/