I recently got a hold of a, yes old, but still fairly capable GeForce 8800GTX (I always wanted one of these!). It's the Asus version with the GRAW 2 skinned fan
The thing is, it's really loud! Like even when it's not doing anything, the fan is like running full speed! I don't know what the issue is! I heard it was common for 8800GTX's to be hot, but many of the reports I've seen didn't say anything about the 8800GTX being so loud.
Another thing is, the GPU runs at like 70-degrees celcius, that sounds kind of hot to me, my HD 4890 doesn't even get that hot!
Intel Core 2 Duo E6300 @ 2.3GHz
6.0GB DDR2-667 RAM (1x 2GB DDR2-800, 1x 2GB DDR2-667, and 2x 1GB DDR2-667)
500W Antec PSU (2x 12V rails at 22 amps)
eVGA 750i SLi motherboard
Asus GeForce 8800GTX 768MB GDDR3
Keep in mind, this is just another computer I have, and I managed to get a hold of an 8800GTX, it's not something I plan to upgrade lol, already have my own system for that
btw, My friend has an 8800GTS 640MB version (yes, the old G80-based graphics card) and his runs a lot quieter than mines, yet the difference in performance (according to online reviews at least, I haven't tested it yet) is not even that big?
I am assuming that this card is in used condition? If it is then you could try to blow out the inside and try to clean it out to see igf there is any built up dust inside. You could then download a copy of MAI's Afterburner to try and control the fan speeds but if it is heating up even with the fan going fast then there could be something wrong to make it heat up like that. You may need to replace the thermal compound between the gpu and the heatsink.