CPU Fan sounds like a lawnmower/leafblower

Jan 7, 2019
Hello. I have been browsing through this site and others for a couple of days now attempting to find a fix to this problem, with no topic really explaining a similar problem unless I misunderstood something.

I am not a computer buff by any means, but over these past couple of days I've acquired some information which may provide some insight. Ultimately, the fan is rather scary sounding and I am concerned. It is also very loud and I live within a dorm.

The sound seems to originate from the CPU fan and, even after I cleaned it out, it continued to make such a noise.

When in the BIOS, the CPU temp remained between 13-33C when the noise was occuring. The fan's RPM dropped from approximately 3100 to 2100.

The specs on my computer says it has an am3+ socket.

The purpose of this question is to possibly gain a more directed solution since there's far too many that I've been seeing on others. Some range from reapplying heat glue, messing with the BIOS, replacing the fan, to modifying the motherboard, etc. Some seem rather extreme, and I am unsure if they are even viable.

I personally think it is simply the CPU fan hitting a wire or having a loose bearing but want a second opinion. I can also post other specs.

Video of the problem: https://youtu.be/elLrUPTMLWU

EDIT: I've seen some of the responses already and will select an answer this weekend when I get the new fan (I live in the dorms as stated so delivery will take time). I'm unsure what "posting an answer" will do, but I thank those who replied for taking the time to do such.




On behalf of Tom's Moderator Team, welcome aboard!

Your suspicions are correct. What you've described is classic "bearing chatter".

This occurs when bearings become old and worn / dirty / corroded / sticky / dry, or otherwise out of mechanical tolerance. The motor's shaft is no longer properly supported between the bearing surfaces as it rotates, so the shaft is instead free to oscillate or wobble ... or "chatter". Sometimes the chatter will stop if the plane of rotation is changed, such as repositioning the case on it's side.

Unfortunately, bearings are not replaceable in devices with very small motors such as PC fans. However, with respect to tight expenses, for a potential $0.00 fix, a clever and patient craftsman with an eye for attention to detail could remove the fan from the cooler, then place a very small drop of thin machine oil in at least the front bearing, which is somewhat accessible. That may be enough to temporarily eliminate the bearing chatter ... but it's not a permanent solution.

The next best economical solution is to replace just the fan only. If a proper replacement can't be sourced, then the only other alternative is to replace the entire cooler. Although stock coolers are relatively inexpensive, keep in mind that whenever a CPU cooler is removed or otherwise disturbed, it's necessary to clean both the CPU and cooler surfaces with alcohol and a coffee filter (or another lint-free material), then apply a small pea-sized drop of fresh thermal compound (also inexpensive) on the CPU before installing the cooler.

Once again, welcome aboard!

CT :sol:


Visually inspect ALL the fans in the system.
Ensure no wire is touching the spinning blades.

Just last week I had to replace my CPU radiator fans for exactly this.
To absolutely isolate the offending fan, immobilize it for a few seconds.

Power off
Use a toothpick and carefully hold the suspect fan from moving.
Power up.
If the sound is gone...thats the one. Repeat as necessary.
Replace it. Fans are cheap. I bought 2 high quality Noctua fans for $15 each.
Silence reigns again.

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