1 2 3 Previous Next 60 Replies Latest reply: Jan 5, 2014 3:36 AM by mkirke
René Bijloo Level 1 Level 1 (120 points)

Hi, today my cpu fan starts running at 44 ºC cpu temperature, and does not stop.  is this normal? it has never started before in 4 years... should i be worried about my mac dying or so?... thank you.


iPhoto '11, Mac OS X (10.7.3), 4 GB RAM 1TB
  • 1. Re: Fan starts running at 3600RPM with 44 ºC
    René Bijloo Level 1 Level 1 (120 points)

    ah, the machine is an intel  iMac 2008  core duo, 3,6 ghz, 4GB RAM.

  • 2. Re: Fan starts running at 3600RPM with 44 ºC
    René Bijloo Level 1 Level 1 (120 points)

    actually the fan starts now directly after some seconds of starting my computer form stanby, at 38 ºC...what is it, some error with the temp. sensor or the fan itself?  thank you.

  • 3. Re: Fan starts running at 3600RPM with 44 ºC
    René Bijloo Level 1 Level 1 (120 points)

    if it helps to understand the issue, some more infor about the status:  average temp: 40 ºC, ODD at 690 rpm HDD at 1400 rpm,  cpu at 3600 constant rpm  i am using Temperature Gauge 3.2.4 . 

  • 4. Re: Fan starts running at 3600RPM with 44 ºC
    Mike Sombrio Level 6 Level 6 (9,540 points)

    Try resetting the SMC

     

    To reset the SMC

    Shut down the computer.

    Unplug the computer's power cord.

    Wait fifteen seconds.

    Attach the computer's power cord.

    Wait five seconds, then press the power button to turn on the computer.

  • 5. Re: Fan starts running at 3600RPM with 44 ºC
    René Bijloo Level 1 Level 1 (120 points)

    Thank you, today, after 24 hours of being off, without unplugging because i did not see your reply, after starting the machine it does not have the problem, fan runs at 1037 rpm, by now. By the way, what is the SMC?

  • 6. Re: Fan starts running at 3600RPM with 44 ºC
    René Bijloo Level 1 Level 1 (120 points)

    Hi, the fan started again, at 32 ºC, directly after starting the computer from standby. I did what you suggested, but no way, still the same issue, and the fan dose not stop.

  • 7. Re: Fan starts running at 3600RPM with 44 ºC
    LexSchellings Level 5 Level 5 (5,675 points)

    Do the SMC reset as Mike said. System Management Controller (low level hardware controller, zit in je hardware).

  • 8. Re: Fan starts running at 3600RPM with 44 ºC
    René Bijloo Level 1 Level 1 (120 points)

    thank you, i will try again today. the fan is driving me mad...hehe.

  • 9. Re: Fan starts running at 3600RPM with 44 ºC
    LostAccount Level 1 Level 1 (80 points)

    If an SMC reset does not resolve the issue then start up from the recovery partition.http://support.apple.com/kb/HT4718

     

    If the issue does persist but not in the recovery partition it may be software that is "running away" — aka consuming a lot of CPU bandwidth and therefore triggering the fans. http://support.apple.com/kb/TS1473

     

    Although TS1473 appears to deal with battery life, on desktops it can just mean more power consumption, which means more heat, which can in some cases, if CPU usage is high, slow down your mac, heat it up and trigger fans.

     

    I hope this helps…

     

    One more thing, it won't hurt to run the AHT (Apple hardware test)…http://support.apple.com/kb/HT1509

  • 10. Re: Fan starts running at 3600RPM with 44 ºC
    René Bijloo Level 1 Level 1 (120 points)

    Hi, thank you for your message, but by now i do not see the need of doing this, as the fan starts at low temperatures, so ther is some sort of malfunction. I suppose now there might be a sensor problem, if there is such a thing inside like a temp. sensor. I have to remark that my machine is 4 years old and never started the fans in this way before. Today the behaviour is a bit different, as the fan is now slowing down, which makes me feel some better...i will observe and maybe contact Apple technical support in case it is a hardware issue. 

  • 11. Re: Fan starts running at 3600RPM with 44 ºC
    LostAccount Level 1 Level 1 (80 points)

    Hi Rene

     

    You will notice that an SMC reset can help with fan issues, see http://support.apple.com/kb/HT3964

    Fans

    The computer's fans run at high speed although the computer is not experiencing heavy usage and is properly ventilated.

     

    -

     

    Have you ever installed software, if you remember that might affect fans or increase their speed etc.?

     

    -

     

    Remove the following file, com.apple.PowerManagement.plist from /Library/Preferences/SystemConfiguration

    -you will need to enter your admin password to remove it and you will need to restart the mac.

     

    -

     

    I would investigate your computer's performance with Activity Monitor. It is possible that you have an application that is consuming a lot of CPU and therefore increasing fan speed.

     

    -

     

    You could even try the following test(s)

    1) If you are on Lion, start up the mac with command-R to enter the recovery partition. The nice thing with this is that it's just a stock basic OS that starts up the mac, if there is no fan noise, well we could argue that your mac is probably ok from a hardware perspective because the software running is very basic, just the basic OS.

     

    2) You could go farther and install a clean OS on an external drive. Granted, this would not be your software setup but it would help rule things out further in terms of a hardware or software problem.

     

    3) Step 2 above is probably the most effective but none of your software would be there but it's nice test bed. Same Apple hardware and software that shipped out of the box.

     

    4) Listen for any noise, might it be your hard drive that is dying and starting to cause heat, thereby increasing fan speed, Disk Utility can show you the SMART status of your internal drive – open Disk Utilty, select Macintosh HD and you will find SMART status, if it reads anything other than passed, the HD is reporting some issue to Disk Utility. If this is the case, backup (which you should always be doing anyway) and replace the drive.

     

    Are there other symptoms along with fan noise? Is there a noticeable heat increase somewhere specific on the machine?

     

    When troubelshooting, reduce complexity. Connect as few devices as possible, load as little software as possible.

     

    Maybe your software is not uptodate?

     

    Isolate the issue, install OSX on an extrenal drive and update it. Does the issue persist?

     

     

    If you do decide to get it looked at, consider contacting AppleCare instead, they will diagnose over the phone, your call to them is not very expensive, they will charge for the phone call but it's for one issue for 30 days. It might be cheaper than taking it in for service.

     

    The nice thing about AppleCare is you can ask related questions along the way, they can be very helpful. Let them know if you don't understand something, they are very patient.

     

    I can help you further if you wish, just let me know.

  • 12. Re: Fan starts running at 3600RPM with 44 ºC
    WZZZ Level 6 Level 6 (12,195 points)

    Remove the following file, com.apple.PowerManagement.plist from /Library/Preferences/SystemConfiguration

     

    -you will need to enter your admin password to remove it and you will need to restart the mac.

    No, that has nothing to do with it. That's for the Energy Saver Prefs.

     

    If it's a hardware issue, reinstalling the OS will make no difference.

     

    4) Listen for any noise, might it be your hard drive that is dying and starting to cause heat, thereby increasing fan speed, Disk Utility can show you the SMART status of your internal drive – open Disk Utilty, select Macintosh HD and you will find SMART status, if it reads anything other than passed, the HD is reporting some issue to Disk Utility. If this is the case, backup (which you should always be doing anyway) and replace the drive.

    Isolate the issue, install OSX on an extrenal drive and update it. Does the issue persist?

    Maybe your software is not uptodate?

    This is all nonsense. As in makes no sense.

     

    I would investigate your computer's performance with Activity Monitor. It is possible that you have an application that is consuming a lot of CPU and therefore increasing fan speed.

    Rene already stated that this happens with the CPU at only 44C. So this is pointless.

     

    Rene: FWIW, I would run the Hardware Test in extended. It might pick up a faulty CPU fan/temp sensor. You might also try several more SMC Resets. Sometimes several are needed. This time, after disconnecting the power and waiting ten or so minutes, hold in the power button for around five seconds, then continue with the procedure.

     

    http://support.apple.com/kb/ht1509

     

    Might also try a PRAM Reset (Not ususally related to this issue, but can't hurt to try.)

     

    Hold in Cmd-Option(alt)-P-R together at the startup chime, wait for two more chimes, total three, then let go to finish booting.

     

    Message was edited by: WZZZ

  • 13. Re: Fan starts running at 3600RPM with 44 ºC
    LexSchellings Level 5 Level 5 (5,675 points)

    René, the fans normally run at 1000-2000 rpm and will increase in speed when the temperature comes up (eg higher than 60C). I believe the max speed is about 6000rpm. When the Mac overheats the system will shut down to avoid damage. A good info widget is the iStatPro widget (free).

    Forget about what Lostaccount posted. Reread WZZ's post.

  • 14. Re: Fan starts running at 3600RPM with 44 ºC
    Mike Sombrio Level 6 Level 6 (9,540 points)

    WZZZ, now I'm curious. I've seen other posters refrence holding the power button while doing an SMC reset, but what does that do for an iMac? I know with Mac laptops where you can remove the battery that's one of the SMC steps, but on an iMac? I'm not aware of an reference from Apple telling you to do that.

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