When I first got my Mac way back in September of last year it was very quiet. So I played some games and got the thing real hot. After several months of this abuse the fans slowly became louder and louder until I couldn’t sleep anymore. Literally! So I brought the 17 inch slab of aluminum back to West-Edmonton mall and had the Apple store install new fans. All was quiet again… For a few months.
Now being a perfectionist I refuse to put up with any defect. This fan issue came back with a vengeance! I was pissed. Now the 90 day warranty is waaay long gone and I didn’t trust Apple to fix the fans even if I paid for it. No, I think they would probably charge the $100 for new fans that have the exact same defect – not being perfectly engineered for continuous flawless operation. Nothing is engineered properly these days.
So I took matters into my own hands. I dismantled the laptop, then the fans. First note, no dust. I blew them out recently so I know it’s not dust collecting unevenly causing harmonic imbalance in two fans. Upon inspection of the shafts and bearings, I noticed that they were too dry. So a big drop of full synthetic 5W-30 motor oil in each axle was delivered and then I closed the fans back up. I spun them with compressed air and noticed that I couldn’t hear or feel them spinning at 10 thousand RPM. Marvelous!
If your MacBook Pro sounds like a lawnmower, use a set of jewelers screw drivers to take the thing apart and oil the fans. It will sound like you broke the fans because you won’t hear anything. Not even acceptable levels of humming or whirring at 5000 RPM. Totally quiet, but the rush of air is proof that they are in fact spinning.