Pulsating Fans on G5

Discussion in 'PowerPC Macs' started by gary513r, Mar 16, 2009.

  1. macrumors newbie

    Mar 16, 2009
    Recently upgraded from my trusty old G4 Mirror Door to a G5 Dual 2.7.
    Immediately noticed that the fans constantly pulsate when I do anything that requires any muscle InDesign, PhotoShop, etc.
    Web surfing she's as quiet as a mouse.
    Is this common or do I have a problem that can easily be fixed?
    Running 10.4.11 with 4 gig of ram and two brand new WD 640 gig hard drives.
  2. macrumors 6502

    Feb 13, 2009
    System Preference ----> Energy Saver ----> Options ----> Highest
  3. thread starter macrumors newbie

    Mar 16, 2009
    Did the settings as you indicated and restarted but still pulsates - not quite as bad as before but still pulsates.
  4. macrumors regular

    Feb 28, 2009
  5. macrumors 65816


    May 20, 2008
    Make sure the thing isn't dumping its coolant into its powersupply...
  6. thread starter macrumors newbie

    Mar 16, 2009
    Hadn't thought about coolant leaks.

    Will check it out tonite.

    Thanks everyone!
  7. macrumors newbie

    Mar 5, 2009
    Toronto, Canada
    I had the exact problem with my Dual 2.5 G5. I had it tested for everything regarding the temps, fans, processors, etc.

    Nothing came up in those tests and the tech's impression was it had to do with the OS. Whether that helps you or not, you might be able to look into a different version of OS to try a fix.

    Incidentally, I traded the machine in for a 2.8 iMac and I'm glad I did.
  8. thread starter macrumors newbie

    Mar 16, 2009
    Checked for leaks. Found no trace where it would normally show.
    Downloaded some freeware that shows temp readings and all seems to be in good order so I'll just have to ignore the pulsating fans. After reading some articles it appears that this is common with 2.5 and 2.7 G5s since they run hotter than the 2.3s which are not liquid cooled. Thanks all for the input.
    She's still a fast beast.
  9. macrumors regular

    Jul 11, 2004
    If you can get it to an Apple Store, there's a utility they have that can perform something known as a thermal calibration; it recalibrates the thermal sensors that control the fans; perhaps in this case this is what you need.
  10. thread starter macrumors newbie

    Mar 16, 2009
    Thanks Earl,
    We have a store here in KC. I call them and check it out.
  11. macrumors 6502

    Feb 13, 2009
    You should also make sure it's not too dusty. If the heatsinks are covered in dust they wont cool as well. The temp will rise quickly and the fans will cool it off, but then it will rise again.
  12. macrumors 68040


    Aug 21, 2004
    ditto on this and ditto on temp gauge re calibration and ditto on highest settings for performance. I know that pulsating thing it is very annoying.
  13. macrumors 65816


    Feb 10, 2003
    Buckeye Country, O-H
    I would think that the pulsating fans would have something to do with either the sensors, or the Firmware. I remember back when i was in school, one of our Video Labs have twenty five G5's, and in that lab there were 5 PowerMacs that had this issue.

    I could swear that Apple released a Firmware update for the Fans. I think it had to do with them revving up to the highest speed during some tasks, during operation.
  14. thread starter macrumors newbie

    Mar 16, 2009
    Thanks all.
    Checked for dust last night. Very clean. Could barely see any when blowing it out with compressed air.
    Will look for firmware update but was told that the last 10.4.11 complete update had those included.
    Probably next move is to run it to the Apple store here in KC and have it checked out.
  15. macrumors 6502

    Mar 23, 2009
    In my experience with the 2.7s, most of them just do this.

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