"Whirring" fan noises.

My seccondary computer Power Supply fan makes a really loud sort of grumbling whiring noise whenever I start it up after leaving it off for more than 10 minuites or so. At first I cleaned it and that worked for a while. (Breaking a sticker saying do not open power supply : No serviceable parts inside) [No serviceable Parts My ass]

Now the only way I can get rid of this noise by blowing into the back of my computer soon after starting it. There is never a problem once it is balanced and running. I leave this computer on 24/7 anyway as it acts as a server for my dialup internet connection.

Dust in the bearings may be the problem. You can probably quite easily open the fan and clean these with a little machine oil. (Be careful - not too much, and clean all excess off - You don't want oil dripping in your case, or getting flicked arround by the fan) - This will void your warranty if there is any.

Also, is there anything stopping the air flowing freely through the fans, such as a mesh of drilled holes in the side of the case(with just as much case blocking the airflow as free space). Some types of fan openings can induce excess pressure on the fans causing their life to be greatly diminished. To test for this take the fans out of their mountings and then just hold them with air on both sides and try turning them on. If the whirring noise is gone, Then it may be worth cutting out the impeding mesh and maunting the fan back. Remember to get something to cover the fan to stop you getting your fingers stuck. You can buy special wire mesh things from your local computer shop, or on the net.

Im not sure about the cold. It could be. How Cold?

Last of all you might try blowing sharply into the fan once it starts, you never know, it might work like it did for me.
Oh, and after that, you chuck them and get some more.

Just interested, but which way do the fans blow?, (I'm assuming into the case at the bottom front and out of the case at the top back?)

Hope this helps
-Chris

One last thought, have you thought buying some dust filters for all places air enters your case. This could stop most of the dust getting into your computer, but you would need to clean them quite often.

Thanks. I had considered this, but wasn't really sure if I should attempt it.

That might be worth trying.

Oh, I couldn't give you a numerical figure I'm afraid. But I leave my windows open during the night, and occasionally won't even turn my computer on until after midnight. (The noises seem to occur more frequently, after a period of inactivity, when it's cold. So I thought it worth mentioning.)

Yes.

No, I hadn't. Thanks.

Well, I greatly appreciate the thoughts. If the problem persists, I'll try each suggested step (with the purchase of new fans left until last, as there's no decent computer stores in my area).

Thanks again.

I had a similar problem, dunno exactly what causes it perhaps its gettin old..

All you need to do is take out the fan remove the rubber motor cap and put in a few drops of oil (I used my hair clipper oil). Worked great