Help from fellow M2 14 Inch Mac users .... fan issues.

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Level 1

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Help from fellow M2 14 Inch Mac users .... fan issues.

Hi,

I am having a very odd problem in that my M2 MAX Macbook pro 14 Inch fans are coming on at full speed randomly without any obvious link to the CPU temp as reported by iStats menu - temps are always in the 40C region. Also the fan RPM does not show on the Macs Fan Control app when this happens , yet when they cycle up normally under load they do show up there.

It is quite irritating when the machine just randomly becomes a hair dryer for no reason , it is happening as i type this and the CPU temp is showing as 39C. Do i have a faulty unit i wonder ?

Mark

Posted on Sep 14, 2023 4:11 AM

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Answer 1

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John Galt

Level 10

155,240 points

Sep 14, 2023 6:02 AM in response to markfrombuck

Please read About fans and fan noise in your Apple product - Apple Support. If you dig down through the links in it you will eventually find this passage from Keep your Mac laptop within acceptable operating temperatures - Apple Support:

"If your Mac laptop gets warm even when it isn’t doing tasks that require intensive calculations, or if it has fans that run for a long time, use Activity Monitor to check CPU activity. Look for malfunctioning processes that can put a significant load on the CPU and check for unexpected fan use. If issues persist, close and open the lid on your laptop, or restart your computer. ..."

Post a screenshot of Activity Monitor if you wish. Use the Energy pane, or CPU sorted by %CPU in descending order to see which apps or processes are using the most energy or placing the greatest demands on your Mac's CPU, respectively. To show the most relevant information I suggest selecting "Active Processes" from Activity Monitor's View menu.

Other thoughts addressed in the above Apple Support documents but are not emphasized enough IMO: never use cases, covers, or "skins" on a Mac.

If nothing helps please write back for additional suggestions.

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Answer 2

Sep 17, 2023 8:17 AM in response to markfrombuck

having this web site open:

notebookcheck.net

is consuming 30 percent of a CPU. This is likely due to heavy Ads on that site. Close that window (and every Browser window) when you are not actively using its data.

Bookmark the sites you need to return to later instead of leaving them open.

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Answer 3

John Galt

Level 10

155,240 points

Sep 17, 2023 11:21 AM in response to markfrombuck

Apple Diagnostics will exercise the fans and measure their speeds to confirm they're doing what they are being commanded to do.

Use Apple Diagnostics to test your Mac - Apple Support

You don't need an app to tell you a fan is objectionably loud. Uninstall all that stuff.

Take a screenshot on your Mac - Apple Support explains how to take a screenshot.

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Answer 4

markfrombuck Author

Level 1

9 points

Sep 18, 2023 3:15 AM in response to John Galt

Hmm that is interesting - the act of running the diagnostics seems to have stopped the problem. So far it has been a few hours and no fan noise at all under the same load conditions.

As far as I understand these machines do not have an option to reset the SMC other than a reboot which I completed a few times. Yet the behaviour is totally different since running the diagnostics with no other changes.

Mark

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Answer 5

markfrombuck Author

Level 1

9 points

Sep 16, 2023 11:26 PM in response to John Galt

The fan is spinning up to max around 20 times an hour , here are two screen shots of the cpu and temp at this point - there is nothing obvious that triggers it. On this occasion the fan was running full pelt.

One thing that is very odd - is that when the machine does this the RPM of the fan shows 0. Yet when I play a game and the fan spins up normally the RPM does show on the app ....

Mark

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Answer 6

markfrombuck Author

Level 1

9 points

Sep 17, 2023 8:27 AM in response to Grant Bennet-Alder

Not in this case no , I have done a bit more sleuthing. When the fans come in like this they come on at the max speed that you would normally hear when the machine is updating , I cannot explain this other than they come on at a different tone and speed than the normal whoosh of the max fans that are present under system load. I can test this with TG PRO and max out the fans , it is a completely different sound than when the fans are running at 6500 RPM normally. When this problem occurs TG PRO shows the fan RPM(s) as 0 yet the fans are running unpleasantly loud. The example i showed did have the website showing as 30% , but this problem happens randomly with no load. I am pretty technical - a developer so I know my way around a machine and what is normal and what is not - and this is deffo not normal.

I have deleted iStatsMenu and some other apps that were running helpers in the background and will keep an eye and see if this helps. I also have TGPro logging fan and temps in the background so I can use the data to show what is going on.

Mark

Thank you for your help and all other ideas welcome :)

Mark

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Help from fellow M2 14 Inch Mac users .... fan issues.

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