sounds like it needs a clean and new TIM
"Thermal interface material" for between the heatsink and contact with the chip.

He he he.
Its easy taking the gpu apart. Its just about 10 12 screws. If you can build a computer its nono harder.
That card is old now. (still good tho) so the Tim will be dry. You could clean the inside better while doing that. I think you could get 5c off that easy. Will make it quieter as well.
