How to Oil a PC Fan
By Josh Fredman
The weak link in a computer fan is its bearing -- the part that allows movement between the fixed components and the rotating blades. As time goes on, the bearing wears down from heat and use, eventually depleting its lubricant until the fan begins to seize. When this happens, you may hear a buzzing or whining sound, and if you leave it untreated, the fan will gradually slow down until it stops completely, in which case that area of your computer will begin to overheat. You can prolong your fan's life by giving it a bit of oil.
Turn off your computer and completely unplug all cords and cables from it. This includes the power cord, data cables, and I/O devices like your mouse and speakers.
Open up the computer case and remove components as necessary to get to the seizing fan. You will need an appropriate screwdriver in most cases to remove any intervening panels and covers. Discharge excess voltage from yourself by touching the computer case each time before you touch an electronic component inside the computer.
Peel back the sticker at the center of the fan. Some fans have a cap below the sticker or in lieu of a sticker; remove that as well.
Dribble or spray a tiny amount of light, electronics-grade mineral oil onto the bearing. You can use a narrow straw or syringe for a more precise delivery. Fans use one of two bearing types. In a sleeve bearing system, you will see two metal rings, one inside the other, that rotate to the touch. There should be a little gap at one point; oil that and rotate the sleeve to spread it around. In a ballrace bearing system you will see a series of ball bearings. Put the oil onto the ball bearings. In both cases, use no more than a few drops, and don't fill the reservoir with oil. If you put in too much, remove the excess with a cloth by placing the cloth upon the oil surface and letting capillary force slowly soak it up.
Let the oil percolate for a few minutes, then close up your machine and start it up. The whining should be completely gone.
Items you will need
Light mineral oil, electronics grade
Straw or syringe (optional)
Some types of ball bearing fans use a sealed-for-life configuration that you can't open without damaging the equipment. For these fans you have no choice but to replace them.
Josh Fredman is a freelance pen-for-hire and Web developer living in Seattle. He attended the University of Washington, studying engineering, and worked in logistics, health care and newspapers before deciding to go to work for himself.