My car is an 07 Grand Caravan (sexy, huh?) that I took in for an oil change the other day. While there I mentioned it was making a loud whirring noise, especially after going down the interstate for awhile and then when I turned the wheel. My mechanic changes the oil and gives me two estimates because from where the sound is coming from he couldn't definitively say which the problem was. $1100 for new rack and pinion, or $600 for a power steering pump. Over half the cost of the pump was labor. I've replaced power steering pumps before, and I couldn't recall them ever being this big of a pain in the butt, so I googled the bejeezus out of this when I got home. For starters, yeah, apparently changing the power steering pump in my caravan is a pain in the butt and can be time consuming (though one youtuber shortened the process substantially by finding a way to take the thing out from the top and passing it along the back of the engine). I also stumbled on a lot of posts of people having similar problems, and fixing it by replacing the power steering reservoir. There is a little screen in the bottom of the reservoir that gums up and impedes flow enough to starve the steering pump of fluid. Leading to the whirring sound. Or as one person call it, a moaning. I couldn't honestly say my car was moaning at my touch. $30 and some scraped knuckles later I got the reservoir changed and the whirring sound has disappeared. The steering is also more responsive. Just thought I'd report on my little adventure and give a heads up to anyone who might find themselves with a similar problem. Also, it just doesn't hurt to google these things before committing to any sort of repair that sounds the least bit iffy.