I have a 94 Lumina APV with 3.1L engine. It has a loud whirrre noise in front. I thought the tires were the problem but I replaced and it still is making the same noise. Any ideas would be appreciated.

MOst probably a worn out bearing (hub) assembly. Check these out on same subject in the Transport forum : same car, same issues.
http://www.automotiveforums.com/vbulletin/showthread.php?t=648414
http://www.automotiveforums.com/vbulletin/showthread.php?t=451870
http://www.automotiveforums.com/vbulletin/showthread.php?t=639220