I had a problem with my 17" (2009) MacBookPro. Kept freezing, losing Wi-Fi etc.
I ended up pulling the back cover off and removing the fans. There was quite a bit of dust etc. built up.
A drop of oil on the spindle, and then put them back in (checking they span properly by blowing on them).
So far, so good - but its been less than 24 hours.
If you go this route, DON'T use WD-40 (as suggested elsewhere on the interweb) and make sure you have a good set of screwdrivers to deal with the tiny screw heads.
If this works for you (or not), please post. As usual, YMMV and caveat emptor! If you muck up your computer, that's your problem, not mine.
PS I also did an SMC reset and zapped PRAM as part of rebooting.
iStat menu now reporting fans ~ 2,000 rpm (silent - was spinning at around 6,000 rpm prior to this). CPU temp is Ok too.
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