PC makes grinding noise when turning on

[Tomtom111]

Hi,
Recently a grinding noise can be heard when I turn on my PC, but not always. So far it has happened twice, the first time I looked inside my PC but found nothing, and the second time it stop after about 5 minutes once the computer had been turned on. I have literally no idea what it is as nothing is touch any of the fans and both HDD's in my build feel fine when I rest my hand on them.
I've made a video of the noise, for which the link is below. You may have to turn your volume up slightly to hear it, but it is much louder in reality.
YouTube Video
Any help will be appreciated,
Tom

 

[Computer0304]

The CPU cooler is most likely loose because I've had a similar issue where when the CPU fan spins fast, it makes a similar noise.

 

[Tomtom111]

But the cooler is clamped down to themotherboard... I'll check it but it seems unlikely, and also if the cooler was loose the noise would continue whenever the computer is switched on.

 

[Computer0304]

Well it depends on how loose it is. The cooler mounting could be getting loose. Sometimes it will go back in place and stop, and it can stop when the fan slows down.

 

[ignatzatsonic]

Disconnect your case fans one at a time and see if the noise disappears.

I listened to the noise. It's got a strong "rotational" component to it. Highly likely it's a fan of some type. It's not an electrical "humming" noise. The noise doesn't become audible immediately--it gets loud only after the PC has been on a few seconds.

Could even be a power supply fan or video card fan.

Could be a fan loose in its mounts, rattling as it speeds up.



Don't know what type of CPU cooler you have, but check the mounting of that fan too.

Less likely it's a hard drive issue.

 

[Ranger4]

Tomtom11. Grinding noises are mostly always caused by some rotating part, usually a fan. Dry bearing are frequently the cause & getting any oil into them is almost impossible.
Fans are found in the Power Supply Unit, the CPU & often under the graphics card, which can sometimes be hard to see. Listen carefully close to each one. Sometimes you can disconnect the fan or momentarily stop it & see if the noise stops. The best solution is to replace the offending fan.
If you have additional case fans just disconnect each one in turn & see if they are the cause.

 

[Tomtom111]

Upon close inspection, it appears that it is the front intake fan that is causing the noise. It was difficult to reproduce once I had removed the fan, but when it was still installed I was 95% sure that it was the fan. So I cleaned the blades and the casing and screwed it back into the case, just to see if that somehow would make a difference, and so far it hasn't made the noise. Before a final judgement is passed, I'm going to see if the noises returns in the near future.
Thanks for your help.