heat sink fan

[Michael Mcpherson]

The fan on the video card of my cube started making an ungodly (and loud)
noise.  when I remove the fan, it stops making the noise, but when it is screwed
in...the noise is terrible.  I'm guessing that the plastic has warped or somethihg
so that the pressure is making the blades of the fan rub up against the heatsink.
loosening the screws helps (or at least changes the pitch of the whine).

I don't want to replace the whole fan if I can avoid it.  does anyone know of a source
of heatsink fans that will fit and do the cooling job?

alternatively is there something I can try to reduce the noise?  tape or something to damp the vibrations?

Thanks much :)