PC making weird noise, probably CPU fan

Hey guys, for a while now I kept hearing this grinding noise coming from my pc. I thought it was my IDE harddrive at first but I now think it might be the CPU fan. I turned it off to stop the noise (this sometimes works) but when I restarted it gave me a bios error saying CPU fan speed was too low (Threshold is 1200RPM and usually runs around 3150). The weird thing is it's sporadic, It's working fine just now.

System Specs are:

asus a8n-sli se (socket 939)
x2 4600 with stock cooler
2 gig (4x512) corsair value 400 mhz
gigabyte 8800gt oc
Jeantech arctic 600W PSU, (not the best but it scored ok on a review Toms hardware did)

Is the CPU fan the likely culprit and can you recommend a decent replacement fan, preferably one that I can then use on my next upgrade to either Intel or more likely AM2+.

Cheers

A much better way to see if it is the fan is to take your finger and press it against the center of the fan to stop it from spinning, when it is making the noise. If the noise stops then it is the fan. Pretty simple aye?

Fans cost $5-$10, stop trying to find one that can be reused, just go get another fan. Make sure you get one with sufficient RPM. Don't get one with too much wattage draw like the Vantec Tornado, they draw too much current from the mobo. Just get a regular CPU fan with enough RPM. Needless to say check your existing fan mounting for compatibility.

Oh, don't stick your finger in the blades, in case you didn't already know that.

5000 rpm seems really high for a PSU fan.

Found it for cheaper on ebuyer.com, was craftily hidden under graphics cooling. Also ordered some arctic silver and the scythe mine revision B as I may as well overclock this to gain some speed. I have accidental damage insurance anyway lol. Love the concept that it rewards you for being a fool.

Hello