Those fans are attached to a propietary cpu cooler with heatpipes, and you have to get the original part from the manufacturer. Damned laptops!. I have a noisy beast, an HP omnibook XE4500 that has an anoying fan that drives me mad, and seems there is no fix.
Of course there's a fix, a fix that's bloody trivial if you have
a window in which to remove your HSF, eye protection, some air tools with hardened metal drills, a few suitable replacement fans, and perhaps a spare Zalman VGA heatpipe cooler.
There are probably alternate prime trivial methods, from testing the fan electrical performance and responding with the appropriate ultrasonic cleaning (in distilled water, machining detergent optional,) line filtering (2 uF at the laptop end mayhap), go-lucky electronics countermigration treatment, aerosol-drop oiling (as not to kill it with a whole drop of oil on first try), and adapting new and promising spares to your old cooling solution's profile.
Myself, I'd love to just replace the stepping of the CPU with a better one, but I don't know how (and electronics modules are past my casual dentistry.) Less heat in the first place, that way.