abayacal

There is a sound, best described as a humming, not loud but loud enough to notice when at a stop light or stop sign. Sound is not there when car is in idle, only when revving in park or in gear.
When I turn the steering wheel to the right or left the sound is also there so assumption is the source is coming from power steering unit.

Is it related to the PS pump/belt? If so, I have read in other postings online that's pump or belt needs to be changed. Or simpler yet, there's air in the unit and needs to be bled. My PS fluid level is at normal and there is no PS leak.

Any help would be appreciated.

Oro

I have an Acura that did just this precisely 20k miles ago. Here's what I did

1) add a few ounces of SeaFoam to PS reservoir, drive a day or two.
2) get a quart of good synthetic ATF, like maxLife, Mag1, etc.
3) Do this:

http://www.toyotanation.com/forum/10...ce-needed.html

If your fluid is staying level and not dropping, this will likely take care of it.

This also implies the car has had hard use and I'd consider changing the ATF if that has not been done recently, and other things attended to like PCV, ISV, etc.

The rest of the can of seafoam can go into the AT before flushing it, and some through a vacuum line to clear the intake. Nothing wasted here.