Fan makes loud noise on startup and only on startup

[moutaindew101]

So, about a week ago, every time I started up my computer (Which is only once a day), one of the fans in it would make a very loud noise. Back then, I just jiggled my case a little and it stopped, making me think something got caught in the fan and I got it out. It persisted for about 4 days, and still only happened on startup. Regardless of any games I played, it never started up again until I shutdown and started up my computer. So, on the 5th day, I took my case and cleaned it out. Considering I cleaned it out a few weeks earlier, there wasn't really anything in there. However, after that, it didn't make the noise again. Until today. The noise is the same, but quieter than the previous times. And instead of jiggling my case around, it just stopped on its own after a minute. Nothing seems to be wrong because I'm not getting any fatal errors, but I'm still worried since the noise is back. My case is 2 years old, so I'm guessing one of the fans is dying, but I don't know for sure since I still don't know which fan is making the noise.

 

[das_stig]

Sounds like a fan bearing dying.

 

[zenx]

When you start up your computer the fan controllers aren't yet 'controlling' anything.. They just start up on full rev and slow down afterwards as your OS boots.
With that in mind and the things you have said, there could be plenty of stuff causing it...
First you're saying that when you cleaned your pc the noise stopped. This could either be because in fact it was dirty and you got rid of some dust or because some cable is getting in the way and as your fan speed increases the fan actually sucks the cable towards it and is hitting it with the blades (that would explain why jiggling the case would stop it and also why the cleaning stopped it since you were moving the cables around).

Open up your case and inspect if there are any cables hanging loose near fans. Normally you would want to make some proper cable management which also increases airflow and helps a LOT with cooling (that means using the features of your case to try and weave the cables through to the other side if you have room then back at the point where you need to connect them... depending on your case). If your case doesn't allow for some fancy cable-management then the least you could do is try to neatly secure the cables together so they occupy the least amount of space and don't get in the way of any fans.

Regarding the fan dying. Fans are small electric motors with blades attached.. so dying isn't really an option for them unless the motor burns out in which case it stops dead and doesn't tend to make noises... What CAN happen however is dust entering near the axle from where it spins and slowing it down / stopping it and even forcing it to come loose which allows for sideways motion which does produce a terrible noise and makes the fan spin at a crawl.

So as a solution, just open up your case and power up your computer while the case is open.. and try to identify the source of the noise...
If you see a cable hanging loose and touching the blades, secure it somewhere so it can't happen.. if one of your fans is making the noise on its own, power down and further inspect it.. if it's a bit hard to turn by hand, your can try to properly clean it, by completely removing just the fan.. holding it above the sink and pouring rubbing alcohol near the axle while spinning it by hand until it spins fine (be sure it's completely dry before putting it back).
Hope this helps,
Cheers!

 

[LoveHatemyPC]

So, about a week ago, every time I started up my computer (Which is only once a day), one of the fans in it would make a very loud noise. Back then, I just jiggled my case a little and it stopped, making me think something got caught in the fan and I got it out. It persisted for about 4 days, and still only happened on startup. Regardless of any games I played, it never started up again until I shutdown and started up my computer. So, on the 5th day, I took my case and cleaned it out. Considering I cleaned it out a few weeks earlier, there wasn't really anything in there. However, after that, it didn't make the noise again. Until today. The noise is the same, but quieter than the previous times. And instead of jiggling my case around, it just stopped on its own after a minute. Nothing seems to be wrong because I'm not getting any fatal errors, but I'm still worried since the noise is back. My case is 2 years old, so I'm guessing one of the fans is dying, but I don't know for sure since I still don't know which fan is making the noise.

I have the same problem, I think Zenx is on to somthing with the rig booting the fans up to full speed, cuase as soon as the pc is on and everything is fully loaded ready to go the whole pc seems to just calm down and the fans become a gental hum