Fans constantly running, and run during "sleep"

Discussion in 'MacBook Pro' started by DrDomVonDoom, Jun 17, 2013.

  1. DrDomVonDoom macrumors 6502


    May 30, 2010
    Fairbanks, Ak
    I have a 2011 MBP 13" and recently its starting doing this thing were the fans are constantly running. I will put it to sleep and at night the fans will kick on.

    I check cpu usage, it says user cpu usage at 25% but nothing is running.

    When I unplug my battery from it in this 'state' it says I have about 2 hours in battery life. What could be pushing the CPU like this?
  2. case2001 macrumors 6502

    Sep 9, 2010
    If you have not disabled Power Nap, it could be the issue. Power Nap will run tasks in the background even when the machine is "Sleeping". It will shut the machine down when it reaches a low battery level or the CPU reaches a predefined temperature. This can happen while the machine is on battery or plugged in to the charger. You have to disable it in both modes. I had the same issue on my new Retina MacBook Pro. There is also a wake on WiFi that can contribute as well.

    Do a search with my handle and you will find the threads.

    Good Luck.
  3. Yahooligan macrumors 6502a


    Aug 7, 2011
    Power Nap isn't available on the non-Retina MBPs so it can't be that.

    25% user CPU and "nothing" running isn't possible, the OP just isn't seeing what's running. Open up Terminal and run "top -o cpu" and find out what processes are sitting at the top, other than top. :)

    The fans coming on and there being CPU usage means something is running, just need to know where to look to find out what it is.

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