from your description it looks like you have a leak in the system, or the compressor is bad.
charge up the system with new Freon and oil. the AC should work for some time, if you have a leak. if the compressor is bad, it will not blow cold air at all.
i recommend going to a shop that can charge the system with the correct stuff and help you diagnose the problem (that's what i did). they can add the "glowing" liquid to help locate the source of the leak.
once the problem is located (leak or compressor), you will have to evacuate the system, and replace the defected parts.
if its a leak, it will probably coming from one of the o-rings/lines.
in my case it was from the evaporator. not an easy fix, but doable.
look at my previous post on that matter.
http://986forum.com/forums/performance-technical-chat/36713-ac-question.html
boxster S
Threaded Mode
