CPU Fan. (by 4 users)

Some times a fan will tilt just slightly off its axis. Even a small difference can cause the plasdes of the fan to touch againts the casing and be the source of increased noice.

Try setting the PC on its side. Does the noise level change?

Fans are a part of a PC that are almost always in constant motion, and thus are subject to faster degradation than other PC components. You should be able to easily replace the fan with a new one to eliminate the noise.

You cleaned the dust off, therefore it will run faster, and louder.
Also, you probably didn't place it in right or tight enough and so it vibrates against something.

Don't worry, but make sure that if you notice that it gets very quiet all of a sudden your fan may have failed and u should save all work and shut down immediately. Not very likely.
But fans are usually easy to replace; you could buy fans for 15$ and all you have to do is place them on the case and plug them in. There are instructions all over the internet.

Hello,
Check the fan power cable is correctly fixed
check the wires are touching the surface of the cpu fan
if the problems continues replace the fan and fix it correctly.

Let me know if your problem is solved and rate me as FIXYA!

MBA Runner has a Gateway 500GR whose fan ran too loud and constantly. I simply removed the cpu fan and heatsync then cleaned out excessive dust. That solved the problem. Heatsync is bolted to the mother board by a bracket. Should the bracket shift, you will need to take out the mother board to reattach the heatsync.

Ok, what I did to fix this was removed the fan and heatsink. Put some fresh thermal paste on the heatsink and then replaced just the actual fan and now it runs much quieter than before.

I am monitoring the fan speed and CPU temp and all is fine ;-)

I could have replaced the heatsink and fan I guess but I wanted to know what was causing the problem.

New fan and some thermal paste and it's all good again.

Thanks to all for your help and I hope this may help others too.

DONT EVER PUT A COMPUTER ON ITS SIDE UNLESS IT IS NOT RUNNING!!!!!!!!!

If the fan was a thermal sensing fan then the sensor might have got bent. If both wires on the thermal sensor are touching, It will run at full speed. This will make it quite a bit louder.

Well a fan that is 4.5 years old can really be dry. You might check to see if it can be lubricated by pulling up the sticker on the fan. Sometimes you can add a drop of oil on the bearing and stop the noise and increase the life of the fan.

Did you make sure the clamps were on tightly and lock into place.