Greg5OH

As someone said, weird things happen when the temps start falling.
Recently I noticed my PS pump is getting loud at idle. Theyre no jitteryness in the wheel but you can hear it whitrring while idling and the noise gets ever so slightly louder when you jiggle the wheel.

Admitedly..I dont know the last time the fluid was changed. So first thing-change the fluid. But lets talk hypothetically, could it be the pump going out? Is the fluid just cold and very viscous so the pump is working harder? I forgot to listen for it after it was warm.
But I dont recall it making this noise last winter.

Neomoogle

In my experience, when a PS pump starts to whine it usually means it's starting to die. Does the noise get worse or louder when turning the steering wheel?

oldskewel

iTrader: (1)

I don't know if it's the same for a 2000, but for the earlier ones (including my '91), the first thing to check when you have any sort of PS problem is the steering rack solenoid filter. The solenoid is accessible on the steering rack, easily seen after removing the left front wheel. When you remove the solenoid, you'll see a non-replaceable mesh screen (you can remove it, clean it, and put it back, but as far as I know it cannot be bought separately unless you buy the solenoid for $1000, and outside of ClubLexus nobody seems to know about it as a maintenance item), which is probably clogged with (in your case) 14 years of PS system debris. Clean that out, replace it, and see if there is a change.

In my '91, when I did it at ~160k miles, it was severely clogged, and cleaning it made a dramatic improvement. A clog at that point in the system raises the pressure throughout everything upstream, causing leaks, component failures, and reducing PS power assist.

The whine could be caused by the increased back-pressure resulting from the clogged screen.

I'd first try to see if your 2000 has such a screen, and if so, do that job at the same time you change the PS fluid.