Here's the noise when I turn the wheel. Takes a minute to get there Louder when it's cold.

 

Had the fluid completely redone. Full drain and replace w/ correct synthetic. No noise for a week. Now it's back again.

 

Your gonna have to replace your pump or rebuild it I have to do the same and will do a write after I get my exhaust made, new tires installed, window tint and alignment so it may be a bit.

 

This is a bit of a long shot, and I'm not trying to insult your intelligence, but have you checked the fluid level? The noise is exactly consistent with a reservoir that's low on fluid AND the plastic reservoir becomes stained and doesn't show an accurate level from the outside. You mentioned the fluid was flushed and replaced with synthetic which should have put the system at the correct level. After this was done the noise was gone. A week later it comes back...? Could there be a leak somewhere which lowered the level enough to cause the noise??? Pull the cap off and double check by looking into the fill hole. Also the noise should be noticeably louder when the cap is removed...

K7q also provides a very good point re the tiny filter.

 

No offense taken. I appreciate the suggests. After the flush, zero noise (at idle or driving) even when the steering wheel was turned. The local mechanic has always done a good job. I'll take a look tomorrow. Recently the whine completely disappeared for 30 miles then started up again. If the pump is failing, the noise shouldn't stop then reappear. Thanks again.

 

A leak depletes the fluid level creating a whine. The whine prompts you to flush the fluid. Problem solved...

A week goes by and the same leak depletes new fluid are you're back where you started. Your mechanic did his job. It doesn't matter if the pump is brand new or failing a low fluid level will cause it to make noise. A pump starved of fluid will sound like a sheet metal grinder through a stethoscope...

 

I found a video about what I'm talking about.

https://m.youtube.com/watch?v=lCG2TFnXxa8

Happens all the time to me when I'm working on Toyotas / Lexus power steering system.

 

I checked the fluid level at the reservoir. Cold start and car was level. Clean, slightly red fluid. Using a q-tip dipped into reservoir, level was roughly a 1/4" above the max line. The colder the outside temp, the louder the noise. Not as bad today (at 70). I don't know if mechanic cleaned filters. In the video, I cranked the steering all the way to the right and then left. Feedback appreciated.

 

Its either air trapped inside the system, the bearings in the pump are starting to go or the pump itself is disitagrating slowly due to age and brake down of the seals and such.

 

Here is a possible solution;

https://www.clublexus.com/forums/ls-1st-and-2nd-gen-1990-2000/845789-low-temperature-power-steering-fluid-options.html

Perhaps the administrator would facilitate a cut and paste of linked information onto this forum

 

The problem keeps changing. This morning, steering didn't make any noise until all the way to the right or left. This afternoon, I started the car. When I moved the wheel at all, it made noise. The "whine" has been there for weeks. Except one day (driving on the freeway) suddenly nothing. Completely quiet.

It doesn't look like the shop removed the reservoir. Necessary to clean the filter right? That's the next step. If the problem was just a little noise in the morning, not a big deal. However, I do want to get rid of the steady high pitch whine at 70-80 and get back to enjoying Lexus comfort. Thanks to everyone for the suggests.

 

You might try asking a Lexus dealer. At least get a diagnosis and quote for a fix. Even if you deny the suggested repair you might eventually save some money instead of just swapping out parts that are not the cause.

 

I'm all out of advice on this one...

The last thing I'd try before springing for a new pump is cleaning the filter(s). Take it back to the mechanic who flushed the fluid and ask him to remove the reservoir and clean the filter. Check post #37 above as I believe there's also a filter in the hose union that mounts on top of the pump. Once you know the filters are clean and the noise returns it may be time for a new pump...

 

Thanks for the good suggests. Local doesn't know Lexus. I'm going to see my indy (Lex) which is a long drive but worth it. I'll have him clean both filters, check the current fluid for crude and look for leaks. After that, decide on what to do. Hearing the "dentist drill" sound w/ the stethoscope makes me think it may be mechanical at some point. Much louder than my neighbor's Tundra (pretty much the same engine). Sent my indy the video. His first suggest was air. We'll see. Thanks again.

 

Good idea. Agree it's time to get an expert opinion. My indy is a Lex master tech. It's a long drive which is the only reason I didn't do this sooner. Thanks for the suggest.