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SRLMJ23

macrumors 68020
Original poster
Jul 11, 2008
2,323
1,423
Central New York
This is has happened twice before, and tonight was the third time. It has also only happened running macOS Mojave. Anyway, all the sudden out of the blue my fans will just spin up to full blast. Tonight I only had Safari open with two tabs, both tabs were on MacRumors. The only thing I can do to stop it is turn my computer off. I ran Apple Diagnostics and it said everything was fine. I am a little baffled by this as it seems to be a completely random issue. It never happened under Sierra/High Sierra, so I wondering if this a bug in macOS Mojave? Anyone else with this same MacBook Pro (or even a different MacBook Pro) ever had this issue?

I greatly appreciate in advance any help you can give, and thank you in advance for your help!

Full Mac Specs: i5 2.7GHz, 8GB RAM, 256GB, Intel Iris Graphics 6100.

:apple:
 
Were you monitoring the CPU at the time?

You could do an SMC reset etc. Some activity monitor screenshots would be great if you got them though.
 
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Were you monitoring the CPU at the time?

You could do an SMC reset etc. Some activity monitor screenshots would be great if you got them though.

Unfortunately I did not get any Activity Monitor screenshots because I was in my other bedroom, and came out and my MBP was doing this, so I had no idea how long it was doing it, so I just shut it down because I do not want to burn out the fans. For all I know, they could have been spinning at full blast for 10-15 minutes, that is about how long I was in the other bedroom.

I think I will try an SMC Reset, cannot hurt any. Next time this happens (I hope it doesn't) I will go into Activity Monitor and see what is going on.

I mean the only 3rd party apps I have are: 1Password, Beats Updater, Speedtest, Wipr (for Safari, hmm...maybe this?), Intel Power Gadget, Coconut Battery, and Firefox (which I honestly use super rarely!). None of these 3rd party apps run in the background, for example, 1Password in Safari is turned off. The only one that runs in the background is Wipr which runs when Safari is open and possibly even when it is closed? Can anyone recommend a better Safari ad-blocker?

Edit: I also use Ghostery, which gives me that warning in the Safari Preferences/Extensions tab that says "This extension will slow down your web browsing." Ghostery obviously runs in the background when Safari is open, but I am almost positive it does not run at all if Safari is closed.

Would there be anything in Console under System Reports etc...that would help?

Once again, thank you in advance!

:apple:
 
I wouldn't be too concerned. I would do the SMC reset and I would also keep Activity Monitor open. I always have it open on and minimized so I can easily see if I have any run away processes running. Safari is certainly capable of having them, and I'd bet that a dodgy Macrumors ad could potentially do that too. I don't recall seeing it happen on Macrumors but I couldn't say for sure that I've never seen it either. I haven't had things get out of hand that my fans are going haywire, I've usually caught it straight away because I can always see how hard the system is working.

Ripping DVDs will max out the CPU for extended periods and the 2015 13" is very capable in that regard.

Certainly worth looking into but I wouldn't be too concerned just yet, at least until you have more info.

If you hear the fans going nuts and Activity Monitor shows that the CPU is relatively idle, then that's another issue. If the fans go nuts and the CPU is getting hammered, then the next step is to see what's hammering the CPU.
 
I wouldn't be too concerned. I would do the SMC reset and I would also keep Activity Monitor open. I always have it open on and minimized so I can easily see if I have any run away processes running. Safari is certainly capable of having them, and I'd bet that a dodgy Macrumors ad could potentially do that too. I don't recall seeing it happen on Macrumors but I couldn't say for sure that I've never seen it either. I haven't had things get out of hand that my fans are going haywire, I've usually caught it straight away because I can always see how hard the system is working.

Ripping DVDs will max out the CPU for extended periods and the 2015 13" is very capable in that regard.

Certainly worth looking into but I wouldn't be too concerned just yet, at least until you have more info.

If you hear the fans going nuts and Activity Monitor shows that the CPU is relatively idle, then that's another issue. If the fans go nuts and the CPU is getting hammered, then the next step is to see what's hammering the CPU.

I appreciate your help and advice. I am not super worried yet, however, I just find it odd that literally the only thing open was Safari with two tabs open, the machine was cool to the touch, yet the fans were going crazy. Like I said, this is the third time it has happened, but these "events" happen very far from each other. It is not like it happens once a week, more like once a month or even a little bit more.

:apple:
 
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