From the time the engine turns over, I hear a humming noise from within the cabin. It is barely audible from under the hood. It gets worse when I turn the steering wheel. However, the faster I drive the quieter it gets. And it is also responsive to adjusting my seat, or turning lights on and off.

I always assumed a power steering issue since it got worse with a turn of the wheel. I also observed that the noise disappears if the power steering fluid reservoir is empty. I have had a new alternator installed and a new power steering pump installed, and the issue is still the same. What else could it possibly be? The pressure hose?

 

Pressure hose could be to blame but I will check simple stuff first since it isn't cheap by any means...


Check Belt wear > Check tensioner > Pressure Hose.

 

Welcome Cortez Hadley !!!
So, it appears as though ya had the PS Pump and Alternator replaced......were the other associated components such as belts and tensioners checked at the time ? May be a good place to start, IMO. Hummm !!!!

 

I know for sure that the belts are new, the tensioners i doubt, and i definitely appreciate the suggestions.

 

I would remove the belt and see it the nosie goes aways. That way you can rule out things taht are driven by the belt. Give each pulley a spin with your hand and listen for ANY noise when the belst off. Even a slight noise by hand will be a big noise when spinning with the engine running. Good luck!

 

Are you sure the humming changes when adjusting your seat, or turning on lights? (As that would suggest an electrical problem)

But your other symptoms combined with a new PS pump and new alternator suggest PS rack ($$$)...

 

it may be the air filter housing