MacBook Pro 17" Unibody, rattling Fan, how to solve

Discussion in 'MacBook Pro' started by guru10at, Apr 18, 2009.

  1. guru10at macrumors newbie

    Mar 9, 2009
    My MacBook Pro 17", which I purchased a couple of weeks ago made some rattling noise from the area where the left fan is located.

    The rattling was not too loud but disturbing and noticeable from distances as 5 meters. It occured at any fan speed (which I tested with SMC fan control) but was most annoying at low fan speeds when the notebook was supposed to be quiet.

    I had no time to turn it in and had some difficulties ordering a spare fan from or other Mac spare part dealers.

    So I opened the MBP and had a look at the fan myself. I compared the left (noisy) fan with the right (quiet) one and did not spot any visual differences. None of the fans was clogged up or mechanically damaged.

    So I disassembled the noisy fan. Again I could not spot anything that could cause the rattling. However, when driving the impeller with my finger I could feel some increased resistance at a certain angle of impeller rotation. That probably was the source of the fan rattling. Now I removed the impeller (including the shaft) from the motor.

    Now I looked for anything I could mechanically adjust. As the fan is very simplistic, there is not too much. The only thing I spotted was the fitting of the impeller shaft into the plastic impeller, which is a tightfit design.

    So I tried axially dislocating the impeller along the shaft by approximately 0.2mm. That worked.

    I reasembled the fan and tested driving the impeller with my finger again. Constant resistance/friction at any angle of rotation (as far as that can accurately measured by my finger...).

    My MBP runs absolutely quiet since then.

    Btw.: I know, I shouldn't do that at home, while my MBP is still under warranty and of course any slipping off with a screwdriver could result in a few thousend $ damage. But my time is limited; taking it in for a repair had easily consumed a couple of hours. Doing it at home cost me roughly 15 minutes (including protecting the MBP mainboard with electrical tape before starting surgery on the internal organs of my machine).

    Conclusion of this post: axially dislocating the impeller along its shaft can eliminate annoying fan rattling issues.

    Hope, this post helps anybody, who needs a quick fix for a rattling fan.
  2. toebs macrumors member

    Oct 22, 2008
  3. dudeitsjay macrumors regular

    Mar 26, 2009
    after about 3 weeks of owning my 17'' umbp, the left fan has started to rattle and make noise =[. i think ima take it into the shop and see if they can fix it within a day. if not then i'll give this a shot =]

    It started to rattle after using smcfancontrol to crank up the speed to 4000rpm constant while i was in windows xp to play games and such and keep the 9600gt cooler. I guess the higher rpms on at longer periods of time may cause the fan to start rattling. Of course, we can all be buttsecks for apple and say windows caused my fan to start rattling :D.
  4. Renegade777 macrumors newbie

    May 12, 2009
    Worked for me, thanks...

    I have had the same fan rattle for over a year but it didn't really bother me due to the noise level in the office. I just moved into a new and very quiet office yesterday and the fan rattle was driving me crazy. I found this post while searching for a replacement fan and it only took about 15 minutes to fix it. I should have done this a year ago.


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