iMac Intel Fan Noise

Discussion in 'iMac' started by vaimea, Oct 17, 2007.

  1. vaimea macrumors newbie

    Oct 17, 2007
    I get some fan noise occassionally on new Intel iMac .. is this normal ? Sometimes their is no noise .. apart from this everything is working fine ... look forward to some replies in regards to fan noise.

  2. GSMiller macrumors 68000


    Dec 2, 2006
    Is it a white or aluminum one?

    I've got a white one and when the fan turns on it sounds like an airplane about to take off. But it very rarely turns on (seriously it's not turned on 5 times and I've had it a year). Plus when I take it off of stand by it kinda makes a strange noise, sounds slightly like a cow. I thought cows were Gateway's thing :p
  3. vaimea thread starter macrumors newbie

    Oct 17, 2007
    Aluminum iMac Intel 20"

    It's seemed to have stopped .. all I've done is restore to default on Energy Saver and put it on sleep mode instead of shut down after usage .. (strange) :confused:
  4. richard.mac macrumors 603


    Feb 2, 2007
    51.50024, -0.12662
    OS X causes the fans to speed up when a cpu process takes up the whole two cores of the intel proc in your imac. sometimes a stuck or "frozen" process will take up the whole cpu load causing the cpu to overheat which in turn causes the fans to rev up.
    i suggest looking into activity monitor in the utilities folder to see if any apps are taking up all the cpu load when your fans rev up. kill the process and the fan speeds should go back to normal. hold on to activity monitor... its a VERY useful app. put it in your dock! post haste!
  5. wackymacky macrumors 68000


    Sep 20, 2007
    38°39′20″N 27°13′10″W
    There seems to be a growing number of posts on this and other apple sites regarding 'fan noise' in the new Alum iMacs.

    Most are saying that after a few days of first turning on there new machine the fan begins to speed up often then stay on until the computer goes to sleep.

    Myself and a couple of other people when run the Apple hard-ware test (by booting up holding the D key) get an error code, that, after talking to 3 different people at tech support from Apple was identified as a problem with a temperature sensor switching the fan correctly.

    (I think I could have told them that as the istat widget shows that the CPU fan is running at 3500 rpm, with a CPU temp of only 20 deg C. and 97% of system resources being idle)

    I need to take in it to be fixed. I might see if they will just replace the whole thing, as it is only 3 weeks old. (might even get Leopard pre-instaled ;-)
  6. katmcg macrumors newbie

    Nov 15, 2007
    fan noise

    I am getting a replacement of my aluminium 20" (this is my replacement of the first which I bought on sun - was diagnosed DOA) - this one has loud fan noise when the screen brightness is anything below three notches from full and above 2 notches from low.
    Was on phone with tech support for 2 days, everything we tried fixed it...until the mac went to sleep and woke up (noise again) or shut down then started up (more noise).
    Eventually rang store and they are replacing.
    Shouldnt be any noise at all, get it replaced if you can..
  7. tanzania2 macrumors newbie

    Nov 24, 2007
    Same problem

    I have a new iMac 24. Despite running all the corrective procedures suggested by AppleCare, it makes a large fan noise which runs continuously, and worsens significantly if I tilt the screen somewhat. I am going to seek a replacement.
  8. Tommy Tallarico macrumors member

    Tommy Tallarico

    Jul 20, 2007
    I've never heard a single fan sound of out of my 24" aluminum in the three months I've had it. This includes running things like VisualHub and VMWare Fusion all the time so my cores are often maxed out in Activity Monitor. If you hear it so much that it bugs you, you really need to get it replaced.
  9. jimbama macrumors newbie

    Oct 5, 2006
    I have a white 2.16 20" imac and the fans have been noticable ever since I got it. They run at normal speeds, but they are just not silent like everyone else seems to have. Kind of a constant humming/whirring, but a bit high pitched. It bugged me at first (and still does sometimes) but the computer works fine, and it never seemed worth sending in for repair/replacement.

    As for the super loud jet plane noise, that has happened to me once, and it is defintiely a bit scary- if your computer sounds like that you should absolutely take it in...
  10. boris.jones macrumors newbie


    Jan 8, 2008
    disaster has struck - Fan constantly on from start up!!

    I was enjoying my quiet new mac until today -- disaster has struck!!

    I have a new problem my Imac is only a few weeks old . Turned it on today after being completely off over night (with power supply off also) and the moment I touch the on button the fan kicks in full blast and never NEVER goes off - its a problem!

    Will get my apple care on it on Monday but is this a common problem?

    The fan has never come on before what ever I do!


    I'm Pretty sure its a hardware problem because I have my system externally
    backed on a bootable external HD - guess what the same happens - and it is in fact kicking in instantly on the on button touch way before the system even says hello.

    I'm unhappy about this. - cause It takes so long to set up a new machine -
    for me days - this might mean many days of lost work ahead!

    I was hoping to hear somewhere that this is an easy fix!
  11. freebooter macrumors 65816


    Feb 24, 2005
    Daegu, South Korea
    I have a white 24 iMc that just this week has started to over-rev the fans.
    i have monitoring software that shows CPU usage/temp. and fan speeds, and though my CPU usage is very low (2-8%) and the CPU is room temp (20 degrees C) the fan is still running above 3000 rpm. For a year this thing has been whisper quiet. I think it must have something to do with a recent software update, but ????
  12. boris.jones macrumors newbie


    Jan 8, 2008
    This fixes it on the new alu imac - but only temporarily gets you out of trouble it just switches the fan off - I the reason the fan switches on in the first place = who knows - mine has happened only once so far from a cold start in the morning and so noisy like a turbo fan quite alarming - like those who have posted above - I suspect a hardware temperature sensor /switch !
  13. freebooter macrumors 65816


    Feb 24, 2005
    Daegu, South Korea
    Well, after posting yesterday I went into repair mode, such as i can muster.

    First I repaired permissions. Hey, macromedia permissions needed fixing--odd.
    Next, a restart and a DiskWarrior treatment and another restart.
    Fans back to normal and after a day of use which included some moments of 100% CPU usage by CS3, still normal (i.e. CPU fan spinning at a whisper-quiet 1000 rpm, down from a hoovering 3000+).
  14. JohnnyMac76 macrumors newbie


    Jan 25, 2008
    Ontario Canada
    Intel C2D (White) iMac 24 - fan noise

    I just thought I would post a comment and commiserate about the iMac fan noise. Mine has been whisper quiet for about 11 months, but in the last few weeks the fan seems to be louder than normal. It is not "loud" by PC standards but there is a hum which also has a high pitch depending on how close I sit to the machine. istat says my fans speeds are 600, 1000, and 1300 rpm and termperatures range from 35 to 65°C, pretty normal I think. I've done a SMU and NVRAM / PRAM reset with no effect. I've also modified the power management plist to stop the hard drive after 1 minute to see it it was the drive motor rather than a fan, but its not. Also, and much less frequently, there is the odd "chirping" sound coming from the fans. At first I thought it was the birds outside, but then I woke up and realized its winter and the windows are all shut! :) Anywho, I'm not sure if I should bother with getting it serviced since the whole computer has to be completely dissassembled to get at the fans. However, when the room is quiet, its very audible...and annoying.
  15. bluedoggiant macrumors 68030


    Jul 13, 2007
    MD & ATL,GA
    Well, I'm on the same problem, but i have a hum, and I'm pretty sure its from my HD, I have a Seagate.
  16. lofight macrumors 68000


    Jun 16, 2007
    How loud is this? Does this mean that you can't listen to music properly?
  17. bluedoggiant macrumors 68030


    Jul 13, 2007
    MD & ATL,GA
    Can listen, on that, im actually listening to music. Well, right now i cant hear it since its somewhat loud, but (right now), when the guy lowers his voice, i can hear the hum, I think the Seagate's in Apple's new iMacs are faster than the WD's (and maybe hitachi's) for a FACT, but I think at the same time the Seagate's are the utmost noisiest, my friends WD is DEAD DROP SILENT, but mine is 10x faster:p

    I used to ignore the sound i love how fast the HD is, but now, I'm no fan of this anymore, this hum is ANNOYING.
  18. JohnnyMac76 macrumors newbie


    Jan 25, 2008
    Ontario Canada
    Listening to music

    Its not so loud that I can't listen to music or a DVD. Except when it gets quiet then it can draw your attention. I figure unless it gets even louder or the temps begin to creep up, I'm not going to have the shop tear it apart. Its amazing how sensitive we become to noise from our Macs! My PC at work buzzes away and I could care less, but then again I didn't pay for it :).
  19. harcosparky macrumors 68020

    Jan 14, 2008
    My 24" Aluminum iMac has been on from day one, and it's works fairly continuos as we are trying to rip over 300 DVD's.

    I was concerned because I have never heard my fans turn on, even when I was doing the following at the same time ....

    Ripping a DVD
    Watching a ripped DVD in Quick Time
    Playing a game
    Editing some photo's

    I thought the fans were broken, so I downloaded a program that allows you to manually run them. At least I know the fans work, now if I could only test the sensor circuit!

    Here's a solution - Buy a cheap PC and set it up next to your iMac, you'll never be bothered by noise from the iMac again! :D :D :D
  20. boris.jones macrumors newbie


    Jan 8, 2008
    fan noise very loud indeed

    The fan noise some of us are talking about has nothing to do with sensitivity
    of the ear or relativity of the silence of the otherwise noisless new macs or in comparison to noisy PCs -

    My noise problem was somewhere between a noisy hair dryer and a vacuum cleaner!
    VERY LOUD INDEED !!! - like someone posted earlier "like an aeroplane taking off!" and quite shocking.

    I have had only one bout of this trouble over a 3 month period! It stopped when I pulled the power supply out of the back of the imac.

    if what I am talking about happens o your mac - you will know! with out doubt and you will be highly alarmed!

    It happened to mine randomly nothing to do with workload - and for a short while was stuck on at every startup! - even after an overnight rest and cold start.
    LOUDER THAN A LOUD HAIR DRYER!. the noise of a fan being driven like a turbo charger! WHOOOOOOOOOOO! sounding like its going to possibly wear itself out and seize unless it can be turned off within a few miutes oe so

    Any way, since that one and only spell of trouble, now about a month ago
    I have had no trouble with it at all!
  21. the roach macrumors newbie

    May 19, 2008
    this solved the issue

  22. boris.jones macrumors newbie


    Jan 8, 2008
    problem solved?

    A fair few months on and no reoccurence of my loud fan problem! Though sometimes I now wonder now if its working at all - the machine gets very hot at the top - but no noticeable problems to report.
  23. AlexisV macrumors 68000


    Mar 12, 2007
    Manchester, UK
    The hairdryer-loud fan speed kicks in when things get too hot, but only for a few minutes. Things usually have to be pretty toasty for it to start and it might not need to go into this mode for years. So when it does, it can be startling!

    People worry about temperatures and are scared their Macs getting too hot for no reason at all. When things get too hot, the fans will kick in and they are quite loud.

    If it won't turn off though, even after powering down and restarting, it might indicate a problem.
  24. st9046 macrumors newbie

    May 8, 2008
    I got my new iMac last week and today the dreaded 'hairdryer' fan noise began. It kicks in as soon as the Mac is booted up and is continuous. Just did the 'pull the power' trick and it's gone away thank heavens. Bit of a worry though...
  25. phalewhale macrumors 6502a


    Jun 10, 2007
    Constant fan noise...

    My 3.06GHz iMac is making more noise than my previous 2.8 Extreme...
    The Fans never kicked in at all with the last one, and (i presume) they haven't on this iMac neither.

    However, the overall noise is noticeably louder. When I say loud, it is not massively so, but loud enough to be annoying in my silent office. I can hear it now just droning away...

    I have the iStat widget and it reckons:

    CPU A: 37
    CPU B: 37
    GPU: 46
    GPU Diode: 51
    GPU Heatsink: 44
    HD Bay: 53
    Power Supply: 68
    Ambient: 18
    CPU Fan: 1200
    HD Fan: 1200

    Do these figures sound about right? I'm still not convinced this iMac sounds right. Definitely noticeably louder than my last one. It's not as noticeable through the day because of surrounding noise but I do a lot of work during the night and this hum is doing my head in... Now who's droining on :confused:

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