Power Steering groan on 99' Lexus LS400


#1

Help! Have a lovely 1999 Lexus LS400 with a groaning steering wheel. Had the mechanic diagnose it, power steering pump. They replaced the pump ($545 later) and I still have the same issue. When I picked up the car, they showed me it was still making the noise and thought perhaps there was still air in the system that needed a couple hundred miles of driving to work it out.
Well a couple hundred miles later, I still have the issue.
Any ideas folks? Please help a little old lady out with your wisdom


#2

More than likely the power steering rack. You can ask them since they did not fix your car to forgo the labor on the replacing the rack. Bleeding the pump only takes a few turns of the wheel.


#3

Is there a way to test the car and determine if it is indeed the rack? versus the power steering pump? I am taking it back to the mechanics shop tomorrow. Knowledge is power.


#4

A mechanics stethoscope or a hose to the ear can help narrow where the sound is coming from. My mom took here car to the dealer and to them the wheel squeaked. They replaced the power steering pump and charged her $800. She took it back after talking to me and explained that the “steering wheel” still squeaks. They lubed the brushes for the horn and cruise buttons and all was well. I hate being 800 miles away when someone takes advantage of her.


#5

I do think there was something wrong with the power steering as it started getting very hard to turn when pulling into or out of a parking spot. I am not convinced it is from a bad power steering pump. I suppose it is possible the one they put in is also bad. They said they would “take care of me”, so I hope they honor their word.
BUT I still would very much like them to determine the problem while they have the car in the shop tomorrow so I can be done with this issue. The groaning sound comes all the way up through the steering column/wheel–you can hear it and feel it. I will mention to them the brushes you spoke about. I appreciate your input! Anything else you can think of? They did mention there is a small leak on the passenger side on the rack–could that be bringing a lot of air into the system?


#6

The brushes were a squeaky noise, no groaning vibration. More the likely the internal seal in the rack are bypassing and causing the groaning and stiff steering.


#7

Any chance this groan may not be the power steering at all and may be related to an aged sway bushing? Maybe try to push down firmly several times on each front fender and note if there’s any of that noise present.

The car chances its stance when the steering is turned and the sway bar bushings are probably the originals. With age the rubber hardens and it doesn’t take much movement at all for the sway bar to creak or groan with movement. Think of fingernails on a chalkboard as an analogy.
There are other components that can do the same thing but the sway bar bushings are a common culprit with suspension noises.

As to the leak on the right side of the rack, then yes that would mean a rack replacement is necessary even if there was no noise at all; assuming the leak is a rack seal and not a hose seal leak.


#8

Hard to say via the internet. In my DIY experience, PS fluid leaks are most likely to come from the hoses, where they connect to the rack. It can appear when that happens the leak is from the rack itself. Sometimes you have to clean everything up, they watch over the course of the next week to see if the leak is from the rack or the hose. But since themost common place for a leak to occur is the hose connection, and that is pretty inexpensive to fix compared to a rack job, make sure the shop verifies the leak isn’t just a hose connector leak.

I expect this will turn out to be a problematic rack. But there are various suspension bushings that could cause this too, as mentioned above. And it is entirely possible the problem is the rubber belt that drives the power steering pump. You might try, if you want to try a cheapo experiment, just replacing that belt.


#9

It is back at the mechanics now. I will relay the suggestions and update everyone when I find the answer. thanks for all the input!


#10

Hi Everyone-the car is in the same shop and they are replacing the power steering pump again.
They are afraid it is the rack.
I have 3 questions:#1 is there a specific test to determine if it is the rack versus anything else?
#2 will a bad rack burn out the power steering pump?
#3 is there a test to find out if the hoses going to the pump are somehow clogged with debris?
Your knowledge is appreciated! :slight_smile:


#11

The groaning noise might be coming from the upper strut bearings.

To find out, place your hand on the strut tower while someone turns the steering wheel. If the bearings are shot you’ll feel it on the strut tower.

Worn strut bearings can also cause difficult steering.

Tester