My 5850 was at the brink of death, the fan was buzzing,scratching and basically the sound was horrible.
I opened the card with the intent to remove the fan and re-oil it. Sadly, some screws were stripped, so...I resorted to the hardcore method of forcibly opening it, melting the plastic where the screws were.
So, in the end I was able to open it, making holes in some visible places, but it got the job done. Now, I am well aware of the risks involved in using vegetable oil, either way, I had no choice but to use one
since I had no machine oil and was a Sunday.
Same RPM of the fan, no buzzing, HOWEVER! Temps, were reduced drastically.
Before: 75-81C core, 110VRMs at 600mhz mem,725 core, 1.075mV, 58-60% fan speed.
After: 60C core,83C VRMs, 600mhz mem,725 core,1.075 mV, 45% fan speed.
So basically, temps were reduced with me just re-oiling the fan which just fixed the horrible buzzing sound. It is extremely odd that the temps are now much lower than before.
Of course, since new furniture was purchased, I had to move the computer in a different position, which might have helped about this.