Macbook Pro Overheating/Fan Problem

Question

Here's a thread I posted on my World of Warcraft guild's forums. I'm reposting it here for additional suggestions. Please ignore the WoW jargon if you're not familiar with the game, but be aware that a "raid" is a situation where graphic intensity is at a high within the game, and can be particularly taxing on a system. Also note that WoW is 4.5 years old, and should not be all that taxing overall on a Macbook Pro compared to newer games.
My Macbook Pro runs hot. In fact, almost all MBPs run hot, hotter than your average notebook computer. The norm seems to be 150-160 degrees during high activity situations (games, compressing video, etc.) However, mine is running even hotter. Last night during the raid, it was peeking at around 174 degrees. Bear in mind that I was playing with all settings minimized, but at full resolution 1400 x 900 or whatever it is.
Now the real problem. Two nights ago, after extended WoWing, a fan on the right side of my computer (or what sounded like a fan) started to sound like it was making contact with something else in the computer, creating a light buzzing noise. After a few minutes, this noise had escalated to a full-blown, really-annoying buzz. I exited WoW, shut down the computer, and started it again after about 10 seconds. Buzzing sound was gone, fans back to normal. Decided to watch Lost on ABC.com, which got the fans going a bit, but not nearly to WoW levels (WoW levels being 4500-6000 RPMs, it's idling at 2000 RPMs right now.)
Last night, during the raid, it happened again. If you were in my 20-man raid, you heard it for yourself over my vent mic. I restarted WoW twice during the raid, but after only a few minutes the sound came back. Had to use a frozen pizza in a plastic bag as a cooling pad. Computer was running much cooler (163-165 degrees, normal for WoW on my computer) but the sound persisted. Turned off some addons, capped the frame rate at 20 fps, sound persisted. After the raid, restarted my computer, buzzing was gone, decided to watch more Lost and the buzzing hasn't been back since. I suspect it will be back during Sarth 3D tonight.
Comp specs:
Model Name: MacBook Pro
Model Identifier: MacBookPro3,1
Processor Name: Intel Core 2 Duo
Processor Speed: 2.2 GHz
Number Of Processors: 1
Total Number Of Cores: 2
L2 Cache: 4 MB
Memory: 4 GB
Bus Speed: 800 MHz
Boot ROM Version: MBP31.0070.B07
SMC Version: 1.16f10
GPU:
Chipset Model: GeForce 8600M GT
Type: Display
Bus: PCIe
PCIe Lane Width: x16
VRAM (Total): 128 MB
Vendor: NVIDIA (0x10de)
Computer was purchased in June 2007. Upgraded to 4 gigs of RAM around Xmas. In the Fall, the computer was sent in to have the logic board replaced, because the video card died. They replaced it with another 8600M GT, a card notorious for overheating and dying. Both Apple and Dell provided free extended warranties for computers using the 8600M.
Any suggestions?

Answer 1

Welcome to Apple Discussions!
You might want to run the extended version of the Apple Hardware Test, just to rule out any physical problem with the fan, such as a dying bearing or something like that.
That said, it sounds more like there is a physical interference of some sort. It may be when the Mac gets hot, the geometry changes just enough that a fan blade could start rubbing on the housing. Or possibly there is something caught in the fan blade, like the leaf in my Dodge truck's AC fan that makes noise whenever it is turned up high.
I don't play WOW myself, but I understand that it will make the Mac run hot, and at 6000 RPM, the fans will get a lot of use. There's always the possibility that they might wear out sooner because of that. It's probably a good idea to run the AHT every so often to check for signs of premature failure.
Good luck!