1998 steering wheel groaning sound when turned left or right

[rhkwon]

The sound is a low groan sound kind of like when your skin rubs on a leather couch and occurs when the steering wheel is turned to the left or right. Very noticeable when the car is first started and less so when warmed up but can hear it occasionally. Mostly when the car is still. It feels slightly stiff and feels like maybe there's air in the system?  The noise is coming from the steering wheel area and almost seems like it's inside the column.

I have checked the power steering reservoir and it's still full sans a minor weepage of the hose where the air control valve is.  I have not had to top off the fluid. Pump has never been replaced but fluids flushed with correct auto trans fluid regularly.  And no smoke at startup so I don't think it's the ACV. And no issues with fluctuating idle.  Idle is stable and does not cause any problems when wheel is turned or ac is turned on.

The steering rack doesn't leak but the driver side rubber boot has some weepage. Rack has never been replaced. 

Car has 140,000 miles. Any ideas?

This thread describes my symptoms exactly. http://www.clublexus.com/forums/rx-3rd-gen-2010-2015/597580-groan-from-steering-wheel.html

[Exhaustgases]

Likely the pump, and can be caused by air in the system. Any leaks around the pump? Like the o ring for the reservoir ?

(the above was before seeing the link)

I looked at the link. If it only does it when the wheel is turned why not just say that, all the other info makes it confusing.

I would get the front wheels off the ground, and turn off the engine, and see if it makes the noise then by turning the steering wheel, if its a grommet squeaking then you should hear it, it could be things like bearings and or u joints as well.