I think CPU fan might be failing?

[Samhradh]

For about a month, when I turn on my desktop, I will hear a loud grinding noise. I usually turn it off right away and leave it off for a while. When I turn it back on, it won't make that noise. However, today I notice it's making the same noise no matter how long I keep the computer off.

I believe it's the CPU fan, but I'm not 100% sure. The reason I think it's that fan is because when I put my ear to that fan, it sounds like it's coming from that one, which is the middle fan.

I turned the computer on about 10-15 minutes ago and even though the grinding was happening, I kept the computer on so I can make this post... after I make it, I will turn it off again, but will check back often to see if anyone replies via phone.

While the computer booted up, the sound continued for a while longer, but once I get to the desktop, the grinding stops.

and before anyone says it, there are no wires touching it at all, and the fan isn't coming off, or tipping to one side ect.

 

[USAFRet]

An empty paper towel tube, or piece of rolled up paper...held up to your ear can help localize exactly where it is coming from.

Or possibly stop the fan (gently, with toothpick or finger) and see if the noise stops.

 

[royalcrown]

Touch the cpu fan for just 1 second to see if it stops (the noise). They shouldn't make a grinding noise, ever. The 4 pin type (PWM) do make a weird buzzing that drives me nuts.

 

[Eximo]

Sounds like bearing failure. Fan will have trouble starting and make noise, then settle down and spin normally, for a while at least, at some point it will just stop. If it is the CPU fan, it will give a CPU fan error and not boot up.

I find it happens more often with CPU and rear exhaust case fans then anything else. (Logically these would be handling heat more directly) Contemporary PSU fans are usually pretty good about avoiding failure.

For brief periods it is okay to stop a fan to see if it was the source of the noise. In which case you will need to provide a little more detail to get a replacement fan or replacement heatsink recommendation.