Cleaning out fans = Major decrease in temp (late 2008 macbook pro)


macrumors member
Original poster
Nov 10, 2008
After about 6 months of my computer running hotter than normal and causing odd things to happen when I put switched to the 9600m gt (random game black screen freezes), i decided yesterday to dust out the inside thanks to many articles found online. After taking off both fans, I was shocked to see an insane amount of buildup of dust - like a huge chunk - covering both fans completely.

Needless to say my computer is now running much cooler - a drop from average 70-80C to 40C.

If your computer is hot, i would definitely recommend doing this. It was a very easy process (8 screws for the backside and 3 for each fan).


Staff member
May 3, 2009
That makes sense, I have to do this for my desktop regularly. For my desktop (a hackinstosh) I have a Silverstone FT02 case where the fan and filters are at the bottom of it, and they collect all sorts of stuff. If I let it go too long, the temps creep up.

Good find :)


macrumors 604
Well I finally ripped out the old fans on my Early 2008 MBP (4.1 2.4 C2D) cleaned up all the heat-sync `s, installed the new fans and I am only seeing about 5C difference in CPU temp than when the MBP was limping along on one fan, however it does cool down faster and the general sound level is greatly reduced.

GPU temps see the greatest reduction, which is no bad thing given it`s potentially one of the stricken Nvidia chips and well out of any warrantee surport. Anyway the 4.1 one will shortly be passed to my daughter, the 8.2 MBP will finally take over fully as primary, and with any luck Apple will be releasing the new MBP 9.1 soon which may be worth a look, after all it`s always wise to have a back up ;)

I use Temperature Monitor from Marcel Bresink which gives a very comprehensive picture of a Mac`s thermal performance. Replacing the fans was well worth and relatively simple thank`s to iFixit`s excellent guide. I have more than had my money`s worth out of this Mac, and it deserves to continue to be a useful system having survived the sub tropics, western desserts of China, Middle East, and now the tropics so all in all I am not complaining :apple:


macrumors 604
Just blow them out with compressed air?
Yes and no, you have to be very careful as the fan blades are fragile, and you have to be mindful of the direction of the air flow, blowing from the outside in will only force more dust into the fans, bearing assemblies etc further reducing lifecycle. Best bet is to carefully remove the fans and blast out the heat-sync with the compressed air.

With the unibody it`s just as easy to replace the fans every 4-5 years, blast out the heat-sync and be done with it. My own 4.1 MBP has run virtually non stop since I bought it in 08, only sleeping to travel literally 24-7-365
Last edited:


macrumors 68000
Apr 28, 2005
An octopus's garden
Yes, I also recently discovered what a difference this can make on an old iMac and macbook.The dust buildup is not usually in the fan itself, but the heatsink. You need to carefully remove the fan and somehow suck out the offending dust. I used a vacuum cleaner, but I doubt that's a preferred method. Whatever you do, don't blow it out with compressed air! You'll get dust in places it shouldn't be if you do that! And don't blow into the fan!

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