Anyone have an idea what might be wrong. My power steering stiffens up intermittently. I could be driving in a straight line and then a bend will come in the road and it will feel like my power steering doesnt work, but will a little more effort, it will loosen and feel normal. I also feel it turning corners. It will be smooth, get t little tight and then smooth again. I had it in the shop and they couldnt find anything wrong.,