11

My MacBook (non-pro) Aluminum is a few years old. Lately I experience the problem that my fans are running high even with moderate usage and the body really heatens up.
It did this before, but only under heavy load (videos, flash or compiling of source files). Now it seems like a regular thing.
I also have the comparison to another MacBook Pro, which is definitely not showing this behaviour, so I am quite sure that I am not imagining things.

Also one night when I closed the lid of my macbook, fans would not stop running (it seems it did not go to sleep mode).

Any Ideas what might be the reason?

The only thing I can imagine is actually to open up the body and remove the dust from there with a spray duster.

  • 1
    O yes, it can definately be dust inside the device. You can screw it open, remove the bottom plate and clean it with air. Do not use sprays, as your device can start to get rusty by that. Just cleaning it with air should be fine, and also try to take out the fan, and clean it completely. – Rob Feb 7 '14 at 7:20
  • So I would need a compressor to have air without a spray-can? – wirrbel Feb 7 '14 at 7:54
  • You should be able to use canned air to remove the dust. Do not use a compressor to blow out computer internals! Compressors usually have high pressure and can break fans and other delicate internals. Just use some canned-air to clean the machine. Use the canned air in short bursts. – James Manes Feb 7 '14 at 15:14
  • Related: apple.stackexchange.com/q/211094/3810 – ThomasW Jul 6 '16 at 8:04
  • I had this problem on my 2011 15" Macbook Pro for the past couple of months. Because I had taken up a new technology, I always assumed it was the new server/compiler/packager putting a lot of stress on the system. But looking closely at the activity monitor, CPU use was rarely above 10%! It turned out that the fans were clogged with balls of lint that had accumulated over the years: i.stack.imgur.com/KS1bC.jpg (Credit card for size) – Pekka Jan 20 '17 at 17:03

14 Answers 14

7

You should first determine if your computer is actually working harder due to some process(es) using a lot of CPU when they historically have not. Open the Activity Monitor app and check your CPU idle percentage.

If your system is using a lot of CPU, the higher fan speed is likely justified.

If you are consistently showing >90% idle, while your fans are racing, you likely have a 'mechanical' heat issue (such as dust/grime on heat sinks or some air blockage.)

If it IS a dust issue, I'd expect you would have noticed the fan gradually increasing its 'unloaded system' speed over time.

There are also products that will let you monitor various sensors in your computer. Some will also let you control your minimum fan speed. My favorite is iStat Menus which has lots of options for what you want to watch and how you want to see it.

|improve this answer|||||
3

It looks you have to clean the dust inside. This was the problem I had some time ago.

Can recommend using free Macs Fan Control app to monitor fans speed, temperature sensors and to adjust fans speed.

|improve this answer|||||
3

An SMC reboot will do the trick. I had the same problem after upgrading to Mavericks with my 2012 MBA.....here is a link to how to do it.

|improve this answer|||||
  • Answers should be more than just a link. Can you please explain the contents of your link so that your answer can stand alone in the event that your link becomes invalid? – sameetandpotatoes Mar 24 '14 at 2:36
3

So I have been having this problem for the last couple of weeks . I finally fixed the problem and it was so weird I just had to post how I did it for you guys.

I tried all the regular things every forum tells you to do such as: Reset SMC, Reset PRAM, Ran Diagnostics, Cleaned the fans and heat sinks, Changed power cords ... nothing worked.

  1. I downloaded iStat Menus
  2. I saw that CPU PECI Die was running at 300 degrees
  3. Then I noticed my CPU usage bar would just to 101% and every time that happened a process called CUPSD was activating. So I googled CUPSD and found out that its a wireless printing protocol.
  4. So I went into System Preferences / Printers and deleted all the printers I added the printer I use regularly again And VOILA, The temp on the PECI die went down to 91 degrees and the process stopped happening.

Weird but it worked! Had to share.

|improve this answer|||||
2

Same problem - my finding was a small cotton ball of fiber stuck at the vent of the fan. I obviously had to open the back of the laptop, but it was pretty easy if you have the right screwdriver heads.

I tried Activity Monitor and couldn't find a culprit there. I didn't think my fan was getting dirty, but only did it in the end because I ran out of other options. And... found the problem :)

|improve this answer|||||
1

I had a similar problem with the fan running at high speed all the time. I opened up Activity Monitor and discovered that the "Dashboard" app was taking up some 60%+ of CPU. I deleted all the windows in the Dashboard and the problem was solved.

So clearly I and perhaps others need to be judicious in their use of Dashboard Apps.

May solve other people's problems also.

|improve this answer|||||
1

I had the same problem where my fan was running on high virtually the entire time I was using my Macbook Pro (mid-2014), and found this site.

After looking at the posts here I decided to check the Activity Monitor, and for me, it wound up being Google Chrome. The Chrome Helper processes were many, and multiple instances running at the same time.

After trying (unsuccessfully) to stop each process (they would come right back each closure), I closed Google Chrome completely and the fan stopped running.

Using Safari only, I am not experiencing this problem (so far), and the computer is running much cooler. It looks as if I'll stick with Safari exclusively as my browser.

I can't thank you enough for the info here. I hope this contribution helps others also.

|improve this answer|||||
1

On My MacBook Air, my fan was running like hair dryer. Checked up Activity Monitor window and saw that a HP printer process was running with 300% CPU utilisation.

Realised that, half an hour back, i sent a print command to a HP Inket Jet printer (but had not connected the printer yet on USB). Instead of killing the process, I connected the Printer. After the printout was over, I could see on the Activity monitor, that in around 30 seconds, the CPU was back to normal.

Not sure, it is HP Driver issue or not?

If there is something spooled for printout and the printer is not connected, it must be the bad driver that still tries to use CPU to find out the PRINTER for end less time.

|improve this answer|||||
1

Ok, I had the same issue suddenly and I was going crazy. What fixed it for me. 1. Opened the back case while MBP was running. 2. Blew on my high speed fan (due to my blow it stopped and started again) ha, then within milliseconds to seconds it came back to life - normal fan speed. So my verdict, the fan controller app might have "stuck" so it needs a "manual" reset.

Once again, just blow the fan while powered on.

|improve this answer|||||
0

I would definitely open activity monitor (Cmd+Space then search Activity Monitor) and go to CPU, then look at what is using the most.

Mine was Microsoft Outlook using approximately 250% of CPU. Closed it, fan immediately turned off. If it is a program you use all the time, try finding an alternative and see if it works better.

|improve this answer|||||
0

I wanted to say that this discussion saved my life. I've already tried to do PRAM and SMC reset with no success. After reading the postings I identified my HP printer was taking 388% of my CPU. Then I've searched on how to shut it down (it was not working on the activity monitor) and found this post: https://discussions.apple.com/message/28453132#28453132 After doing that my CPU went back to normal.

|improve this answer|||||
  • 1
    Can you please summarize the content of the link directly in your answer? – nohillside Sep 23 '15 at 14:07
0

My Apple MacBook Pro, my fan would not stop running and the battery was running out very quick. I spoke to the Apple Technicians who could not sort out the problem.

Checked up Activity Monitor window and saw that a HP printer process was running with 340% CPU utilisation.

I went to System Preferences - Printers and Scanners and realised that there were 3 printers connected to it. Once I deleted the redundant printers, the process stopped running and the fans stopped running.

Thank you to this Google search! It's sorted.

|improve this answer|||||
0

Same problem here, on a 2009 MacBook Pro 17" - fans running insanely fast and the underside was too hot to have on my lap. The battery is 7 years old and ready for a replacement soon, so I thought it might be related. Otherwise the machine is still fantastic.

Checked Activity Monitor and the Finder CPU usage was always maxed out, never below 98% whenever I had a window open. More windows just crippled the running speed of the machine.

It turns out that I had the Finder View Options set to show the Size of all files and also Calculate Size for all sub-folders, after inspecting some folder sizes a few weeks earlier. This was forcing the CPU to do loads more work than necessary. I switched these both off and instantly the Finder CPU dropped to less than 2%. The fans calmed, the machine sped up dramatically and was soon cool enough to handle.

Phew! Nothing wrong at all, no need to reset Finder or SMC, replace fans etc, just an overworked Finder. Well worth remembering stuff like this, even if it common sense.

Hope this helps!

|improve this answer|||||
0

I had the same problem. After a while I realized that the fans only ran high when I had Safari open. I turned of the Norton extension, and it resolved the issue. Hope this helps someone out there!

|improve this answer|||||

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .