I have a 2003 Discovery SE7. When in park and in gear, when I accelerate I get a whining noise that increases as I accelerate. Any thoughts on what this may be?

 

possible power steering pump or a clogged power steering reservoir

 

Power steering pump. But more likely one of your 3 Serp belt pulley's. If you can take off the Serp belt and spin each of them by hand...if there is one that feels rough, that may be your culprit. Put a solid bar to your ear on the bolt that holds the pulley. A old mechanics trick.

Also spin your A/C pulley it should spin very free.