shortly after I purchased the car after it sat in cold damp snowy outside weather for several weeks, the steering wheel would make a whining noise like zipping a zipper or rubbing two pieces of jeans together when I wheeled it around. I had the intermediate shaft repaired (which fixed the clunking) and it seems to have cured the noise problem about 90%. I still notice it sometimes. It is alot better though. I also think as the car dried out in my heated garage and got some use on it the problem may have resolved.

Sounds like you may some unresolved issues. Did you look through this thread https://www.gmforum.com/t223290/?

I had the same problem but it was just my power steering pump seizing up