Quick summary: check the screws attaching the fan to the heatsink. They may be loose, or – as in my case – have fallen out altogether, causing the fan to vibrate and strike the shroud.

I’ve had a BFG 8800GT (OC) for 2 or 3 years now, and it’s always been fine: the stock cooler isn’t the quietest when heavy 3d use causes the fan to hit maximum speed, but that’s kind of to be expected. And on ‘phones, or speakers with a fair bit of volume, you don’t really notice it too much.

And then, a few days ago, mine started making an awful sort of “fan clipping wires/hitting something” screechy noise while playing Alien Swarm. On boot up, and during heavy 3d use (ie, when the fan hit 100%) it’d make the same awful noise. Uh-oh time.

It had been a while since I’d given the card a good hoovering, and in fact I realised I’d never dismantled it and cleaned it out properly. So naturally I assumed it was just crud in the fan.

What I realised next is that I have no idea how to get the shroud off the card. Most 8800s have the shroud screwed on: this one has it clipped on, but even with the clips undone there’s a bit of the shroud (around the fan) that refuses to budge, even if you apply a worrying amount of force. I guess there’s a screw under the sticker but it’s the kind of sticker that won’t peel off easily.

So I gave up on that and simply took the whole heatsink off, got rid of as much dust and fluff as possible, did what I could to make sure the fan wasn’t actually touching the shroud, sprayed the inside of the fan with some wd40, and put it back together.

No difference.

Then I took the card out again and had another look. I’d kinda wondered whether the fan noise – given that it only happened at max speed – was the result of some kind of imbalance, so that only at maximum speed would it hit something (and I presumed it was clipping the shroud, as there was nothing else there for it to hit).

And lo! On closer examination, what did I see but an empty screw hole where there ought to have been a screw holding the fan to the heatsink. A quick poke around the innards of my PC later, and I’d found the missing screw, which has clearly fallen out at about the time I noticed the noise.

Bad screw design. Bad something design, anyway. Easy gfx card fix. No need (yet) to replace the card or cooler. I replaced the screw, tightened up the others, and bingo! No more noise.