Can you identify the whine?

[postwick]

2007 Expedition Eddie Bauer. Whine is new. Follows engine RPM. Doesn't change hot vs cold. Doesn't change in gear vs in park. Doesn't change AC on or off. Doesn't change when turning steering wheel. Most noticeable at lower RPMs under 1500.

2007 Expedition whine

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[Greyeagle]

Power steering

 

[Trainmaster]

It's a hassle, but take the belt off and see what happens. If it goes away, check each pulley for roughness. If it doesn't go away, you have bigger problems.

 

[OldSchoolMec]

Is your cooling fan stuck on?

 

[Fastcar]

Sounds louder as you move to the rear of the engine. Get under it and listen at the dust guard on the bell housing.

 

[iowacarpenter]

See if it changes when you rock the wheel back and forth stopped and idling. If it does, then it’s likely PS pump or something in that system. You can also look for bubbles/aeration in the reservoir.

x2 on taking the belt off. That will eliminate a lot of the front end rotating parts. You’ll also be able to spin each pulley and feel for looseness or grinding. If you still have the noise, it could be a vacuum leak or trans pump.

Could also be a PCV valve whining. I had that on my 2016 3.5l. You could feel the buzzing when you touched the valve.