My late '08 unibody mbp 2.53 was really really irritating me cos it was constantly running about mid to high 80's F, and the fans would always be spinning between 3500 and 4500 rpm. This even when I shut *everything* down, and only had the Finder running. Then I found some posting from someone here about resetting the SMC. Tried it and it worked! (Thanks, "someone"!)
It now idles in the mid to high 60's F, and the fans spend much more time closer to the minimum 2000rpm. Sure, when I'm doing builds in Eclipse or visit Flash sites (sorry, just had to get this one in...), the temps do spike into the 80's/90's and fans kick into high gear, but the temps now actually do come down, and the fans do settle back down. The casing also doesn't get quite as hot to the touch.
Thought I'd pass it along...
To reset SMC... http://support.apple.com/kb/HT3964
It now idles in the mid to high 60's F, and the fans spend much more time closer to the minimum 2000rpm. Sure, when I'm doing builds in Eclipse or visit Flash sites (sorry, just had to get this one in...), the temps do spike into the 80's/90's and fans kick into high gear, but the temps now actually do come down, and the fans do settle back down. The casing also doesn't get quite as hot to the touch.
Thought I'd pass it along...
To reset SMC... http://support.apple.com/kb/HT3964