MacBook makes whirring noise very frequently

Discussion in 'Mac Basics and Help' started by music4888, Oct 9, 2009.

  1. music4888 macrumors newbie

    Oct 9, 2009
    My MacBook is a little more than three years old, and I just recently had to replace the hard drive. My new problem is that the computer makes a whirring noise all the time. It rarely happens when I am using the computer. But if it is on and just sitting there, it makes a starting up, whirring noise every 30 seconds or so. Also, if I put my computer to sleep, if will frequently "wake" back up. The screen goes black like it's asleep, and then two minutes later, it's awake again. The only way to get it to stop making noise is to turn it off. Is something wrong? Is there some way I can fix this?
  2. Makosuke macrumors 603

    Aug 15, 2001
    The Cool Part of CA, USA
    The two possible sources are the hard drive or the fan. Can you tell by listening which one it is? The fan would sound sort of low and steady, while the hard drive would be relatively high pitched and increase in pitch (if the drive were spinning down then back up) and/or be a sort of "grinding" sound if it's writing data.

    The fact that it's only when you're NOT using the computer kind of makes me think it's the hard drive going to sleep then waking back up because something accesses it. If it were the fans, you'd notice it more while the computer was in use. (An easy way to test is to go find a Flash game and play it for a minute or two--the fans should ramp up noticeably in that case. If the sound is different, it's probably not the fans.)

    As for the "won't sleep" problem, it could well be related. The cause of that is almost always a peripheral waking the computer up. For example, I have a Logitech wireless mouse. If I put my computer to sleep but don't turn off the mouse, the computer will stay asleep as long as I continue to not touch it (the mouse sort of "sleeps" on its own). If, however, I bump the mouse and it wakes up, the computer will wake up as well.

    Similarly, if you've got something attached to the computer via USB it could be waking the machine up--try unhooking everything but the power cable and see if it wakes itself up.

    Edit: Almost forgot; one other thing that can make a noise is the optical drive. You don't happen to have a disc in the drive, do you? Either that, or is the sound a sort of "vree-chunk" like when a disc gets ejected? I've seen slot-load optical drives go funky and make eject noises randomly.
  3. Cloudance macrumors newbie

    Oct 9, 2009
    Don't know about the wakeup, but the whirring sound is most likely a fan in response to the new (and maybe slightly hotter-running) hard disk. I'd bet the disk is running *just* warm enough to hit the threshold to bump the fan speed over time, then a few seconds of extra airflow is taking care of that.

    Easy way to check is run something like iStatPro and watch the various temperatures and fan speeds as it happens. If temps and fan speeds stay even... it'll indicate a different issue (maybe the Disk.) and either iStat or Activity Monitor can help isolate it.

    If it is the fan, I'd first take the system down to your local Genius Bar (if there's one close) and have them blow out the ducts and inside of the case. Dust and crap can get in there and affect cooling, especially if the case has been opened and jostled around. You can blow it out yourself, but even if you're comfortable I'd let APPLE do it if you can to retain warranty.

    If it's still doing it after that, you can grab smcFanControl and use that to set a base fan speed. Default lowest fan speed on a 2009 Unibody MBP is 2000rpm. if I saw, for example the hard disk temp slowly rise with a corresponding increase to the fan (particularly to the left fan, which cools the HD) to the "middle" speed of 4000 rpm,then drop back to 2000 after a few seconds, I set the minimum speed for the left fan to maybe 2250 and see if that little extra speed dissipates the little extra heat. If not, experiment up and down on the minimum till the fan ceases to speed up and slow back down from time to time, and that's the trick.... for the lowest fan speed, *just* enough RPM to keep things below the happy threshold (where It bumps up the fan speed from time to time).

    Hope this helps.
  4. music4888 thread starter macrumors newbie

    Oct 9, 2009
    Thank you for your help.

    I am almost positive that it is not the fan and is instead the hard drive. No accessories are attached to the computer via USB and no CD or DVD is in the drive. It sounds like it keeps powering up and then down again.

    Do you think this is a problem with the new hard drive that was recently installed? Could it have been installed incorrectly? Thank you.
  5. Makosuke macrumors 603

    Aug 15, 2001
    The Cool Part of CA, USA
    Assuming you're right, and it is the hard drive, the most obvious thing to try is unchecking "Put the hard disk(s) to sleep when possible" in the energy saver preference pane, and see if that makes any difference. (Or, if it's already unchecked, try turning it on.)

    Assuming that doesn't make any difference, my guess is that the drive is doing some sort of power management that doesn't mesh well with OSX's power management, so it keeps trying to put itself to sleep only to be re-awakened by the OS a moment later. Pretty sure the recent "performance update" for new machines was intended to address just such a situation. That doesn't help you and your older computer, though.

    I've personally seen a very similar thing happen to the external WD Green drive connected to my server--the damn thing keeps trying to go to sleep even when it's in active use, and I can't figure out how to bypass that.

    If this is the case, nothing you could do but live with it (if it's not affecting the computer while you're using it, it's not likely to hurt anything), or replace it with another brand of drive.

    What maker/model, out of curiosity?

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