Your fan needs more discipline!
It could be as simple as debris caught in the fan or condensor.
Here's a DIY on replacing / inspecting the fans:
http://pedrosgarage.com/Site_3/Replace_Radiator_Fan.html
I'm not sure if the bearings are servicable, but you can find a replacement fan here:
Pelican Parts - Product Information: 996-624-135-00-M14