Fan is running constantly on my MBP

Question

Fan is running constantly on my MBP

I hope someone can help, this beats me. The fan is almost constantly running, it should't be.

The Activity monitor at the moment is showing that 45% of CPU is idle.

About a third of my drive is free.

I have 500 Gb of SSD, so there are no moving disk heads.

The screen is turned up to a level I want to work with.

I am running the regular stuff -- Word, Firefox, Mail and oter Apple apps, all usual stuff.

The MBP sits on a clear glass desk so heat can disburse through the glass, but the fan is still running.

The MBP is about two years old.

Lion.

I have reset that master thing (sorry I forget the initials) but it's recommeded for this problem.

Please, someone come to my rescue and tell me what I can do to make it possible for the fan to stop.

James

MacBook Pro, Mac OS X (10.6.4), 500Gb SSD

Posted on Mar 23, 2012 4:47 AM

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Answer 1

Best reply

wjosten

Level 10

95,321 points

Mar 23, 2012 4:51 AM in response to James Roberston

Ah...your fans are supposed to run all the time...mostly at 2000 RPM's...that's normal.

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Answer 2

thomas_r.

Level 7

31,989 points

Mar 23, 2012 4:54 AM in response to James Roberston

Mine, at the moment, with a number of apps running in the background, is at 96-98% idle. If yours is only 45% idle, that means something is using a lot of processor time. What process is that?

Also, note that glass is not a good conductor of heat. Not that it should matter unless you're doing something that should generate a lot of heat, like playing a graphically-complex 3D game.

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Answer 3

Mar 23, 2012 6:22 AM in response to wjosten

I don't know the RPM of the fan, but it's loud. I sunds like it is working hard.

James

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Answer 4

Mar 23, 2012 6:27 AM in response to thomas_r.

Thomas, thanks for taking the time to respond. Activity monitor is curently showing 98% idle, and the fan has stopped running. So now I have to track down the process that is using all the processor time. None of the apps shows much activity, and I am not running any games.

I guess I have to monitor the apps and see what is using all the CPU. Are there any likely suspects? Is MS Office a candidate? Are there any apps that are notorious for using CPU?

Thanks for your help.

James

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Answer 5

thomas_r.

Level 7

31,989 points

Mar 23, 2012 6:40 AM in response to James Roberston

It's very hard to say what the culprit might be. It may be some "crapware" that you've got installed and forgot to mention (probably unaware that it's even a problem), or it could be some normal process that is not functioning properly. The only way to be sure is to keep an eye on Activity Monitor and see what that says.

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Answer 6

Linc Davis

Level 10

209,547 points

Mar 23, 2012 6:44 AM in response to James Roberston

Click the heading of the % CPU column in the Activity Monitor process table to sort the entries by CPU usage. You may have to click it twice to get the highest value at the top.

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Answer 7

Mar 23, 2012 7:11 AM in response to thomas_r.

Thomas, I am careful to avoid crapware, as long as you don't count Microsoft products. Thanks for your help.

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Answer 8

Mar 23, 2012 7:12 AM in response to Linc Davis

Linc, I have it like that and at the moment, all is quiet the the fan has stopped. I wil progressively boot up apps and see what happens.

Thanks for the top.

James

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Answer 9

thomas_r.

Level 7

31,989 points

Mar 23, 2012 7:17 AM in response to James Roberston

Thomas, I am careful to avoid crapware, as long as you don't count Microsoft products.

LOL, I suppose I wouldn't count MS Office as crapware, though I prefer to avoid it myself. 🙂

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Answer 10

ds store

Level 7

30,725 points

Mar 23, 2012 7:21 AM in response to James Roberston

Perform a SMC Reset,

The computer's fans run at high speed although the computer is not experiencing heavy usage and is properly ventilated

https://support.apple.com/kb/HT3964

Check your Avitiy Monitor> CPU > All Processed and click it to sort so you can see what's taking your CPU processor cycles and thus making your fans come on.

If your problem went away upon a reboot, it's possible a program you were running had a runaway process.

Monitor the problem and try to localize/narrow down when it and how it occurs

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Answer 11

Mar 23, 2012 7:42 AM in response to ds store

Thanks, I habve already done the SMC reset, and will do it again. I have the activity monitor running sorted so that the highest users are at the top. At the moment all is quiet. I will wait for the fan to come on and see what Activity Monitor says.

Yes, it did stop after a reboot. Interesting about runaway processes. I will keep an eye on it.

Thanks for your help and interest.

James

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