Fan running at max rpm during sleep.

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Level 1

4 points

Fan running at max rpm during sleep.

I have an early 2011 Macbook Pro running High Sierra. The computer was recently reformatted and worked well for over a month. Last week I noticed the fan running at the max rpm as soon as it enters sleep mode. This is happening every time it enters sleep (right when the SIL starts blinking). It doesn't matter how the computer enters sleep mode or if the lid is open or closed. The fan stays running at the max rpm's the entire time it's in sleep but stops immediately when awoke. The computer isn't overheating. It runs perfectly when awake and I have no issue waking it from sleep.

I've checked the energy saver settings, turned off notifications during sleep, turned off bluetooth, reset the SMC and PRAM several times and run the apple hardware test with no errors found. I even installed Macs fan control and limited the fan rpms to 2000. Even with that the fan still would run at 6000rpms while in sleep mode.

I'm not sure what else to check. Any help would be appreciated.

MacBook Pro 13", macOS 10.13

Posted on Jun 7, 2019 9:55 PM

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Answer 1

rcosta887

Level 4

3,604 points

Jun 8, 2019 4:39 PM in response to will_duds

There are a couple of things you can try doing at this point:

Make a Time Machine backup to an external USB drive (which is always a good idea anyway if you don't do that) and then restore from that Time Machine backup by going into Recovery Mode (COMMAND-R). Doing so will actually erase your hard drive/partition entirely + restore all of your data / apps / settings but on a fresh, unfragmented file system with garbage temporary files (cache, etc.) cleared out. There's a very good chance this will work, because if it still doesn't work I would be greatly considering it is a hardware issue at that point.

If the above does not cure the problem then the next step you can do is to then take that Time Machine restored partition, shrink it down 25 gb in Disk Utilities (if you have that much free space even available) and then go back into Recovery Mode and Reinstall macOS to that new, empty, 25gb partition (and not touch your main Macintosh HD partition). By installing a fresh macOS High Sierra to that empty partition you can test to see if the problem persists with a completely fresh/clean/default install of the OS. If this works then it's definitely not hardware and it's some manner of software corruption which you can deal with. If this doesn't work then 100% sure it's hardware.

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Answer 2

will_duds Author

Level 1

4 points

Jun 11, 2019 7:06 PM in response to rcosta887

So I noticed the other night that the Mac would in fact go to sleep without the fan running IF I didn't close the lid and just let it sleep via power saving.

The next night I restored a Time Machine backup from an external USB and that has seemed to fix this issue completely. Hopefully it"s a permanent fix.

Thanks so much for all of the suggestions everyone!

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Answer 3

rcosta887

Level 4

3,604 points

Jun 7, 2019 10:14 PM in response to will_duds

Does your MacBook Pro Early-2011 wake up properly from sleep mode? As in, can you start using it again and then the fan drops down to normal at that point?

Have you tried as a test to go into sleep mode but closing / quitting everything you have open first such that you are essentially going to sleep with no apps open, other than Finder?

Try making a new test-user account, and log into there, and again with nothing open try going to sleep. Does it do the same thing?

How to test an issue in another user account on your Mac - Apple Support

You can open a terminal window and manually delete your sleep image file using the following command:

sudo rm /private/var/vm/sleepimage

Thats: sudo␣rm␣/private/var/vm/sleepimage

Where ␣ = space

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Answer 4

kaz-k

Level 9

51,168 points

Jun 7, 2019 10:31 PM in response to will_duds

Hi,

Boot in Safe Mode if it's still fan running while sleeping.

https://support.apple.com/en-us/HT201262

Also run Etrecheck and paste the result here.

https://etrecheck.com

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Answer 5

will_duds Author

Level 1

4 points

Jun 7, 2019 10:46 PM in response to rcosta887

It does wake up properly and the fan immediately returns to normal. I've tried quitting all apps before sleep. I tried logging out before sleep. I tried logging into another account before sleep. I tried booting in safe mode.

What would deleting the sleep image file do?

I see I need to disable SIP before I can delete the sleep image file so I will try that next.

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Answer 6

will_duds Author

Level 1

4 points

Jun 15, 2019 10:01 AM in response to rcosta887

So after two days I the noticed the fan was doing the same thing as before. I reinstalled from the Time Machine backup and it was good for another day. After that I tried doing the backup 2 more times and it stopped fixing the issue.

Can you explain the second option in a little more detail? I'm trying to wrap my head around it but I'm just unclear on exactly what your saying. Thanks!

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Answer 7

will_duds Author

Level 1

4 points

Jun 15, 2019 6:17 PM in response to rcosta887

I made a 27GB partition of the hard drive and did a fresh install of High Sierra on that. After the install was done i put the mac to sleep. The fan turned on after about 10-15 minutes. I let it run for about 30 minutes to see if it might shut off, woke the mac up and put it back to sleep and it kicked on immediately.

So it appears that this is a hardware issue. What do I do now? Replace the fan?

Thanks.

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Answer 8

will_duds Author

Level 1

4 points

Jun 7, 2019 11:31 PM in response to kaz-k

I tried safe mode and unfortunately that had no effect.

Here is the etrecheck report.

etrecheck report

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Answer 9

rcosta887

Level 4

3,604 points

Jun 8, 2019 1:04 AM in response to will_duds

If the file is corrupted that could easily cause this type of problem. By deleting it, it would be created from scratch the next time you go to sleep.

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