# My Fan Makes a Grinding Noise



## Endrakx (Jan 21, 2013)

One of my fans makes an annoying grinding noise. For some reason, it doesn't happen right away when I turn on the computer, and is often silent for around half an hour before it starts. But when it starts, it doesn't stop until I restart the computer.

This has happened before, and after trying a variety of self fixes, I brought it into a computer repair shop where I had all the fans replaced. The technician there said that my rear fan had seized up, but that it wasn't the source of the grinding noise and he couldn't tell what was. Replacing the fans seemed to fix the problem, though.

However, the problem is back again. It's not as loud as before, but still very annoying. I've already gone into my case and systematically unplugged all my fans to try and see which one is causing the problem, but the grinding keeps happening anyway.

I regularly clean my computer, and I've checked to make sure that there are no cords near my fans. I know it is a fan, however, because I can hear it start to rattle as the noise begins.

Does anyone know anything else I could try? I really want to nip this problem in the bud instead of buying a new set of fans just for it to happen a third time.


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## Basementgeek (Feb 7, 2005)

Hi and welcome to TSF

Are you sure it is not the hard drive that is making the noise ?

BG


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## Endrakx (Jan 21, 2013)

Yes, I'm positive. My harddrive is located in the front of my computer. The grinding noise is coming from the back.


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## WereBo (Apr 5, 2008)

Hi Endrakx and welcome to TSF :wave:

It's possible that a replacement fan is faulty, depending if they used a cheap fan. Alternatively, it might be the fan on your graphics-card (if using a 3rd-party card), your CPU or the PSU.

When the noise starts again, gently rest a finger-tip (best 'digital probe' available :wink on the centre-hub of each fan, not hard enough to stop it or slow it down a lot, just to sense any vibration or change of noise - That should indicate which, if any, fans are faulty.

*NOTE:* - You can't test the PSU-fan using a finger-tip, the fixed grille keeps you safe from the high voltages inside, but with care and a slender non-conductive rod (something like an old plastic knitting-needle will be ideal), you can use the same technique.


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## Endrakx (Jan 21, 2013)

WereBo, I did what you said and found out that it is in fact the fan in my processor's heat sink (it was vibrating so much that I had to only touch my heat sink to feel it). I have a free-standing heat sink, so I was able to easily pull out my fan and take a look.

Everything looked clean, but there is a wire that COULD be rubbing against the fan. I have no way to tell if this wire is what's making the noise, though, and even if it is I can't exactly move it out of the way. It threads in under the heat sink and connects to my fan.


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## Tyree (May 10, 2009)

What are we working on?
PC Specs?
Pre- Built Brand & Model Number
Custom Built- Brand & Model of Mobo-CPU-RAM-Graphics-PSU.


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## Fjandr (Sep 26, 2012)

Either way it would likely be best to replace the fan. If the wire is rubbing, the wear from the fan will quickly work through the insulation creating a shorting hazard. If it's not rubbing, it means that the bearings in the fan either have flat spots wearing onto them or have contaminants inside them. While high quality fans have removable bearings which can be cleaned or replaced with only a bit of trouble, it's usually easier and cheaper to just replace it.

You'll need a fan with the same exterior dimensions (usually 80mm or 92mm square). Depending on how it is mounted to the heatsink, the thickness may or may not matter. 25mm and 38mm are typical depths for CPU fans. The second consideration is the power connector. Fans with a 3-pin connector are fixed-speed fans, while a 4-pin connector is a variable speed (PWM) fan. 3-pin connectors can attach to 4-pin headers and vice versa, but in most cases it's best to stick with the same pin count.


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