MacBook Pro Late 2008 108 Degrees CELSIUS! (UPDATE)

Discussion in 'MacBook Pro' started by darrenscerri, Dec 9, 2008.

  1. darrenscerri macrumors regular


    Nov 15, 2007
    Hi guys, my MacBook Pro seemed to go hay wire! I recently decided to try and max out the CPU (2.53Ghz) and see the resulting temperature. After reading a bit in forums, many people said that there maximum temperature achieved was 85 degrees celsius. I downloaded CPUtest and ran it. I slowly saw the temperature on SMCFanControl climbing from 47 degrees celsius up to 55, then 60, then 70, then 80, then 90..... hey what the hell, fans are still only running at 2000rpm, 95, 99, 100, 102... 105... 108! The fans are still at 2000rpm! These values are in celsius, yes CELCIUS! I stopped CPUtest and shutdown the MBP and reset the SMC. Done the test again same results. Resetted the PRAM. Same Results! I don't know what's happening! I ran two instances of /dev/null and again the temperature rose to 105-108 degrees celsius, with the fans staying at 2000rpm! Should I return my MBP? I know the answer would by yes but can someone tell me what is happening? Am I getting false readings?

    UPDATE: This seems to be a widespread issue, follow these steps to see if your MBP suffer from this issue:

    1) Reset the SMC (

    2) Install a temperature monitor software (iStat Pro Widget, iStat Menu, SMCFanControl, but not Fan Control)

    3) a) Download CPUTest, and run the test with these settings:
    - Test Type - small
    - Repetitions - Unlimited
    - Instances - 2


    b) i) Open Terminal (Applications -> Utilities)
    ii) Type without quotes: "yes > /dev/null"
    iii) Open another terminal window
    iv) Retype "yes > /dev/null"
    (This should load your CPU to 100%)

    4) Observe the temperatures and fan speeds. (Typically, after an SMC reset, the fans start speeding up at about 70 degrees celcius, and stabilising the temperature at about 83-85)

    5) Now, close CPUTest or Terminal (depends on what you used), sleep, restart, shutdown, logoff or change your GPU, and after your system is on, rerun the same test you did before.

    Post your results.

    Attached Files:

    • 105.jpg
      File size:
      142.5 KB
    • 108.jpg
      File size:
      146.7 KB
  2. nonick macrumors member

    Sep 4, 2008
    i also made this test, using /dev/null, just to find out how the fans are reacting on rising temperature. on my mbp, the temperature went up to 80, the fans speed increased to 2100-2200, then 85 and 3000 and then it went to 68-70 and stayed at this level.
    however, i have the 2.4ghz version, not sure if there is any difference...
    it's definitely not normal if the fans stay at 2000 and the cpu goes up above 100°C, so i'd say you should call apple.
  3. daneoni macrumors G4


    Mar 24, 2006
    Something isn't right there. Have it looked at
  4. dukebound85 macrumors P6


    Jul 17, 2005
    5045 feet above sea level
    thats quite hot

    mine tops out at like 90 under full load
  5. Michael CM1 macrumors 603

    Feb 4, 2008
    What's that temperature in American? :D

    JK. I know that's way past water's boiling point. I'd take it to a Genius. My early 2007 MBP has maybe hit 184 Fahrenheit when it's been fully processing for a bit, and the fans are at 6,000rpm.
  6. lscangus macrumors 6502

    Jul 29, 2003
    Newcastle, UK
    my first unit does that as well, is a defective product. You need to get it repaired or exchanged.
  7. dudemac333 macrumors newbie


    Oct 21, 2007
    I have the same problem to darrenscerri, my temp got up to 99 Celsius and still the fans stayed at 2000 rpm... i have 2.53MBP late 2008...
  8. six.four macrumors 6502

    Oct 24, 2008
    ^ mine does the same thing in Mac OS.

    The fans are a bit slower to rev up at higher temps in windows though.

    My experience here:

    As for the OP - if your fans never budge from 2000 rpms.. that is definitely something that needs fixing.
  9. hari-bhari macrumors regular

    Jul 4, 2007
    i cant get my fans to ramp up if im purposely stressing the cpu. but when i play games on the 9600, they do ramp up to full blast. seems like the management is different
  10. hishat macrumors regular


    Oct 14, 2007
    United Kingdom
    Try running some high end graphics games, get the fans to rev up without purposly doing so, if they do rev up, you havnt got a problem. however if they dont, then just call apple your good.

    nothing to lose sleep over..

    and by running games i mean at FULL RES, whilst running youtube videos, jus kinda stress ur mac out.
  11. Nipz macrumors 65816


    Nov 1, 2006
    Whist converting a DVD with HandBrake i got mine up to 101 with the fans at around 3000. The laptop become untouchably hot.

    Think i should take mine to a Apple store too?
  12. milk242 macrumors 6502a

    Jun 28, 2007
    unfortunately, I seem to have the same problem. I ran cputest and it ran my cpu to 90 C but my fans stayed at 2000rpm
  13. milk242 macrumors 6502a

    Jun 28, 2007
    I don't know if this might be related but every time I reset my SMC, the fans go to about 4500-5000 rpm and then return back to its normal state. I really think this issue is a SMC firmware issue and hope Apple issues a fix for it soon.

    One more thing, if someone doesn't have this issue with the new Macbook Pro can you post your SMC version? Mine is 1.33f6
  14. clarksonknight macrumors regular

    Aug 15, 2008
    Washington, DC
    I don't know if I'm having the same issues as you all are, but my late 08 MBP will heat up for no apparent reason, sitting idly and then cool down. I tried downloading smcFanControl, but it says that I'm on an unsupported machine so I can't really tell what my machine is doing. What is this /dev/null everyone is talking about? I'd like to figure out what's going on here before I call Apple Care.
  15. Chris F macrumors regular

    Jul 27, 2007
    Fans not spinning up under load is bad juju. Install smcfancontrol there is no reason you should hit 105C that's just ridiculous.

    I notice the same issue on my UB MBP, OSX is EXTREMELY slow to ramp up the fan speeds. Pretty crappy software IMO.

    There used to be a program that would let you remap the entire temp->fan speed curve, does anyone remember the name? It's worth giving a shot, in the meantime though get smcfancontrol and jump the fans to 4K if you are going to be doing CPU or GPU intensive work.
  16. bengtc macrumors regular

    Oct 29, 2008
    i think smc fan control locks the fans at the speed that is set in the preferences. When i tried it the fans would not increase speeds with an increase in temperature. Try using FAN CONTROL
  17. six.four macrumors 6502

    Oct 24, 2008
    that sounds normal to me... mine fans don't go past 2000rpms unless it reaches about 93-95 C
  18. bolleee macrumors newbie

    Dec 13, 2008
    I have the same problem 2, just tried Cod4 and the CPU and GPU went up to 80° and the fans were still at 2000rpm. Is the only way to get the machine run cooler by downloading smcfancontrol ? o_O
  19. puma1552 macrumors 603

    Nov 20, 2008
    can anyone confirm this?
  20. milk242 macrumors 6502a

    Jun 28, 2007
    I don't think smc locks the fan speed because on my SR mbp, it just sets the minimum fan speed and still allows the fans to ramp up
  21. jsbarone macrumors regular

    May 8, 2007

    I ran CPUtest after looking at your thread. The fans just started to ramp up after hitting 102c. This is done on my 2.8ghz unibody macbook pro. A replacement is on it's way. I guess I'll do this test when it gets here!
  22. jsbarone macrumors regular

    May 8, 2007
    this is probably because of disk indexing. open up activity monitor while it's doing it and you'll see a process called mdworker using up a bunch of cpu cycles.
  23. tom.leman macrumors newbie

    Nov 17, 2008
    My late '08 MBP has got to 108 deg c playing WoW before but I just installed the new SMC firmware released today (v1.2) and my fans are now speeding up much sooner than they were before.
  24. jsbarone macrumors regular

    May 8, 2007
    I ran the EFI update and after installing it ran the CPUtest again, this time with 2 instances running. I think I got you beat OP!

  25. bolleee macrumors newbie

    Dec 13, 2008
    i still wonder if the CPU really likes temps over 80°C, iv'e heard from somewhere that they shouldn't go over 72,5° or is there a difference to the desktop computer processors ?

Share This Page