I put in new power steering pump and serpentine belt to see if that was causing the steering wheel pulsation problem, still have the pulsating on the steering wheel. It doesn't do it all the time, more noticeable when it is colder out and when the car is first driven. after about a minute of driving, it usually goes away. When I make a sharp turn it gets worse momentarily and then gets less noticeable. My thought now is that there is a restriction in the return line or something that is restricting the fluid flow. My car is a 2001 PT Cruiser. I did see an article on the reservoir having a filter on the bottom that can get plugged with goo. Also, I put in power steering fluid but did find a site that said to use ATF+4 tranny fluid. Any suggestions would be appreciated. It is definitely something in the power steering, not brakes. I will repost once I get the problem solved.
Lon Johnston

 

Could be a tire has a flat spot from sitting. As the tire warms up a bit from driving, the flat spot tends to go away. Not all tires react the same. Check your tire pressure to make sure it's up to spec. Try rotating the tires front to back and see if that affects the problem.

 

I had a problem similar to yours. Went on for awhile then one day as I was putting air in my driver's side front tire it exploded! Put the spare donut tire on and noticed that I no longer had the steering wheel pulsation. Bought new front tires and problem solved. Mine is a 2002 limited edition. So check your tires