You gotta replace your ps pump if you take drain the fluid into a clear bottle you can see little black flecks in it that's the ps pump coming apart/disintegrating slowly. I would replace the ps pump and clean out the rwsveoir with gasoline and then use a air wand to blow the crap out .ca rinse again air wand again repeat one more time then rinse out the resevoir with new fluid. Install the new ps pump fill with dexron/merc 3 and call it a day.

 

The car I just let go had a bad power steering pump as told to me by the dealer. I experienced the same noise as you described...a light, dry whirring noise. The pitch would heighten upon acceleration however I did not have the normal noise of a bad power steering pump when turning or difficulty when turning.

 

In regards to maintenance, I acquired an '04 LS430 with 119k. The power steering fluid looked dark and had a burnt smell. After reading the various posts on servicing and talking to my independent Lexus mechanic I did the following. I used a fluid extractor which would pull approximately 1/4-quart of fluid out of the reservoir. After each drive where the fluid would get hot, I would extract and then refill again with universal Castrol synthetic ATF (2 for $10). After 1 1/4-quarts the "whining" stopped but the reservoir "staining" hasn't completely been cleaned and the fluid still doesn't smell fresh. I plan to continue this method and finish the 2 quarts and then put it up on a lift and use a 17mm and 22mm wrench to disconnect the fittings on the steering rack. Any residual dirt or debris should gravitate toward this low point. Hopefully by then the detergent properties will have eliminated the staining in the reservoir and I can then fill it with Amsoil Universal ATF (DexII/DexIII). Since the total fluid capacity is so small (I think its about 3/4-quart?) it looks like the only way to get everything out of the system is by disconnecting the steering rack line set.I haven't seen any "O-Ring" residual in the fluid that's been extracted but then again the fluid was so nasty that the "black dirt/slime" could be O-rings. After I get the fluid cleaned I plan to extract each time an oil change is done and then disconnect at the steering rack at around the 30,000 mile mark.

 

Put the car up on jack stands disconect the return line to the resevoir, have that go into a jug put a funnel that fits snuggly in the ps resevoir hole put some fluid so it sits in the resevoir in the funnel waiting to go in the ps resevoir, with the car in the on position (do not turn the car on) turn the wheel back and fourth to full lock 2-3 times check fluid in funnel if it needs to be filled again repeat this until the fluid comes out of your detached ps line clear red, put everything back together and smoke a j, drink a beer, read a book do whatever you do to celebrate because you just flushed your power steering system.

There is not going to be debris in your ps by the rack the resevoir has a mesh screen that catches all particles, if there is debris its from your power steering pump coming apart and changing your fluid is a band aid fix.

 

Had this same issue with the gf's 06 Accord V6. I replaced the rubber o-ring also and that stopped her whine too, but didn't stop her wine.

 

The intention was to disconnect the return line at the reservoir and follow those procedures to flush (and also clean the reservoir) but upon trying to remove the line(s) it required significant pressure and I decided that "breaking the nipple" off the return on the reservoir wasn't something I wanted to chance after reviewing what reservoirs cost. The independent Lexus mechanic said that his normal procedure to flush is by using the 17 & 22mm wrenches at the line set. If I insert my fluid extractor into the reservoir (I have a smaller hose attached to it so I can bottom out in the reservoir) will this extract what's caught on the screen? Where is the screen located? If you have any advice on how to get the two lines off of the reservoir that lessen the chance of breaking the nipples, please elaborate as my first choice was to clean the reservoir so there wouldn't be any doubt as to whether the PS fluid was breaking down the "black ring" in the reseroir or the O-Ring on the pump itself was slowly dissolving.

 

Someone please correct me if I'm wrong but I'm fairly certain the screen isn't actually part of the reservoir. In the pic you see the tube that mounts on top of the pump. On LS400's the reservoir is mounted directly on top of this part so when they are together the screen is at the bottom. On LS430's the parts are separated by a hose.

I've found using the EVO solenoid on the rack to be much easier than disconnecting the high pressure line if all you want to do is drain fluid,,,

 

yupp the screens in the reservoir i saw it first hand when i was cleaning mine out

 

I had the exact same problem when doing mine use plumbing pliers to move those clips that hold the hose onto the nipple all the way to the middle so you can twist the hose with your hands use a small flathead screw driver to push down the top of the hose on the resevoir then slowly twist the hose with your hand and pull down on the hose keep pushing the hose down with the screw driver and twisting it.

Its a tedious process take your time and it will work though.

 

Mine whined from day one when it was cold outside. If I were to guess, many owners have experienced the same regardless if they have noticed or not. Inherent to the brand?

 

I am beginning to think so i wonder if the oem fluid Toyota/lexus uses is to thick

 

I have an 04. No PS noise when I bought (101). Then started hearing the whine. Had the PS totally drained and refilled (107). Once again, no noise. Couldn't tell the engine was running. Now the whine is back and getting worse (111). Bought a $10 stethoscope (great tool). No problem w/ the alternator pulley bearing. No noise from serpentine belt (done at 90). Idler pulley seems to be quiet. It's the PS pump. Using the stethoscope, can hear a high pitch whine at idle. Sounds like someone using a high speed grinder on metal. Get worse when the engine is rev'd. Changes when the steering wheel is moved L/R. New PS time.

 

 

You should have seen the look on my girl's face when I had a 4' length of 1" PVC plastic pipe up to my ear and the other end touching the alternator, the PS pump, etc, when trying to figure out where her whine was coming from! The look on her face was priceless when I placed it on a ROTATING pulley, lol!

Your post inspired me to buy a automotive stethoscope made by Lisle from Amazon for about $15. When it arrives, guaranteed she'll open it up without asking me, and then ask me what the heck it's for!? That's my cue to proclaim we're going to 'play doctor', LOL.

 

When I drive my 04 (110k), there's some kind of very high pitched "whine" at freeway speeds (70-80) when tach is roughly 1,700 - 2,500. Not super loud but just enough to be really irritating. Kind of like a dentist's drill. Michelin tires are in excellent condition. Other the "dentist drill whine", the car looks and drives well. I tried coasting in neutral. No noise. It's not the stereo. No wind noise. There's a slight vibration at idle which is probably engine/trans mounts.

So to compare, I drove an 06 in perfect condition. Elderly woman owner, full service. Didn't make any noise at idle or any speed. No whine. Just like the 01 I sold.

Can hear the PS pump on mine at idle (loud when cold, can hear slightly when the car's warmed up). Could this be the source? I've heard about 04's having a "mystery whine". Mine didn't need a trans replacement. I did a couple of D/F's. Dealer did the second. Shifts are super smooth. Other than the noise, the car is a perfect low mileage car. Any suggests on ways to solve the whine? Am ready to sell my 04 and buy the 06 (10.5). Perfect one owner but not a Sport.

Side note: the 06 isn't a Sport (mine is) but doesn't feel much different. Not much body roll. There is some road feedback. My 01 was soft. Noticeable body roll and totally insulated from the road.