General

The fact that the sound changes (stops) makes it sound like it's not a permanent failure, like the bearings going out.. if it was, the sound would be pretty constant.

It does sound more like the computer is getting hot when you play a game and speeding up the fan to compensate. If this situation is a change from the "normal" operation, then yes, dust in the heatsinks is a very good possibility as the cause.

Well the thing is.. that it STOPS after a game, and usually it starts when my computer starts up, but i will check for dust in betweene the fins and see if that fixes it

Tie long hair back too ._.

That almost sounds like the fan is a PWM (speed controlled) fan that's being run at maximum RPM to cool the CPU when it's being pushed hard- like during a game.

Dust buildup can cause noise from fans too, and that you can usually fix with a soft brush like a fine water color paint brush and a can of compressed air. Use a flashlight to shine down through the fan blades of both fans and see if you can see a gray blanket of dust in the aluminum fins below the fan. Depending on how the fan is mounted it's usually a simple matter to take the fan off and brush the dust out of the fins and off the blades and the back of the fan.

And- Spring is usually the time overheating problems due to dust buildup tend to make themselves known as the ambient air temps gradually warm up.

And seriously, like djp said, the easiest way to determine which fan it is would be to lay the computer on its side with the side open and the top of the computer to your right, and put your nose down into the space between the video card and the CPU cooler. That puts one fan on each side of your head and gives each one a separate ear. If it only does it after you've played a game, or if that makes the sound more prominent, then play a game with the computer laying on its side like that and THEN stick your nose into it. (Be careful not to touch anything hot with your nose, of course.)

[quote=djpinc19]Open up the case, stick your head inside, and listen carefully.

There are some guides hanging out in cyberspace that have instructions on how to lubricate fan bearings although none of them are particularly easy.

If the bad fan is on the CPU cooler, then you can either replace the 80mm fan or replace the whole darn cooler.[/quote]

its odd becuase it some times does it, im pretty sure its the CPU fan.. after playing a game that demands CPU power the wirring kind of goes away after the game is stopped

When have you last cleaned your computer

Open up the case, stick your head inside, and listen carefully.

There are some guides hanging out in cyberspace that have instructions on how to lubricate fan bearings although none of them are particularly easy.

If the bad fan is on the CPU cooler, then you can either replace the 80mm fan or replace the whole darn cooler.