If you’re noticing your computer fan is being louder than usual, it might be time to take a look at the fan itself. Checking the fan’s condition can help you determine if it needs to be replaced or if there is another issue causing the noise. To check the fan, first turn off your computer and unplug all of its cables. Next, remove the cover of your computer’s case by removing either screws or clips on the sides. Once the cover is off, you’ll be able to see your computer’s internal components. Next, locate your computer’s fan and look for signs of wear or damage. If the fan appears to be in good condition, you can skip this step and move on to checking your computer’s cables and connectors. If the fan is damaged or worn out, however, it will likely make noise when it spins due to inadequate airflow. In this case, it might be necessary to replace the fan altogether. ..

What do you do when a fan on your computer is loud enough to be disruptive to your work-flow, or is ruining the fun when doing other things? Today’s SuperUser Q&A post looks at the best way to catch the ‘guilty culprit’.

Today’s Question & Answer session comes to us courtesy of SuperUser—a subdivision of Stack Exchange, a community-driven grouping of Q&A web sites.

Photo courtesy of el_finco (Flickr).

The Question

SuperUser reader ‘Annonomus Person’ wants to know how to find out which computer fan is being so loud:

What is the best method for finding out which fan is being loud?

The fan doesn’t sound unbalanced, and it isn’t making sounds in a rhythm (not the usual rrrrrrrRRRRRR… rrrrrrrRRRRRR… rrrrrrrRRRRRR… rrrrrrrRRRRRR), it just runs constantly. I am thinking about oiling the fans, but I can’t decide if it is the PSU fan, a case fan, or the CPU fan. If it’s the CPU fan, I will most likely just replace it with a quiet fan. How can I tell which fan is making the noise (if not multiple ones)?

One thing that I think may be the problem is my CPU fan isn’t PWM, so would swapping that out help? There is no “linear voltage” or etc. thing in BIOS, so I think it may be running at full speed. Also, there could be too much airflow because it is also making a whistling noise that you can hear when close to it, and sounds like when I accidentally put part of the side cover over my floor vent to get it out of the way.

The Answer

SuperUser contributors Hefewe1zen, Darrel Hoffman, and Ross Aiken have the answer for us. First up, Hefewe1zen:

Followed by the answer from Darrel Hoffman:

And finally, the answer from Ross Aiken:

A fan-by-fan approach, with a good measure of caution to avoid a nasty shock or injury, is definitely a good way to learn which fan is being loud.

Unplug each fan, one-by-one from the motherboard (or from the PSU, depending on the fan), and when you stop hearing the noise, plug them back in one-by-one until you hear it again (to verify that the one you thought was making the noise actually was). I’d do the CPU fan last; everything else will be fine with ambient cooling for an extended period of time. The CPU fan is the one most likely to have issues.

Granted, if you have a GPU with fans on it, you’ll probably need to use @Hefewe1zen’s method for those.

I just don’t like telling people to put hard objects and/or fingers near fast-moving objects. Too high of a chance of someone hurting themselves (especially if they’re un-coordinated).

Have something to add to the explanation? Sound off in the comments. Want to read more answers from other tech-savvy Stack Exchange users? Check out the full discussion thread here.