Why does the fan on my macbook pro keep running at a high rate for long periods?

Question

Why does the fan on my macbook pro keep running at a high rate for long periods?

MacBook Pro, mid 2010

OS X El Capitan, version 10.11.3

Processor: 2.4 GHz Intel Core 2 duo

Memory: 4 GB 1067 MHz DDR3

Graphics: NVIDIA GeForce 320M 256 MB

163 GB Available

iWorks '09 has has been upgrades to latest versions

No new upgrades are available for the system.

My Question: Why does the fan on my macbook pro keep running at a high rate for long periods?

I assume the fan is running constantly because the CPU is working at a high rate. I have rebooted the systems several times but without any resolution. The bottom of the computer feels very warm at times so I place the laptop on an object that allows good airflow. This problem occurs intermittently every few weeks or so. I wonder if it is downloading a large upgrade, doing a virus scan, or working as a bot. It goes on for hours. Currently, I estimate it has been running at a high rate for for possible 6 hours. Thanks.

MacBook Pro (13-inch Mid 2010), OS X El Capitan (10.11.3)

Posted on Feb 7, 2016 10:11 AM

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Answer 1

Best reply

OGELTHORPE

Level 9

57,305 points

Feb 7, 2016 10:32 AM in response to John (Silver Spring)

It usually will be to dissipate internal heat as a result of running resource intensive applications.

Download and install a temperature/fan speed monitoring application.

Open Activity Monitor to ALL PROCESSES and set CPU to display values from high to low.

When the fan speeds up, post images of both for review.

Also run an Apple Hardware Test:

https://support.apple.com/en-us/HT201257

Note that an error free AHT is not conclusive.

Ciao.

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Answer 2

Feb 7, 2016 11:01 AM in response to OGELTHORPE

Ogelthorpe,

Thanks. I opened Activity Monitor and it showed that an HP device was at the top of CPU usage. I plugged my HP printer into my laptop and it printed a page without me giving any command and the fan slowed almost instantly to an inaudible level. Yesterday I printed the same page and apparently unplugged the printer from the laptop too soon for the printer to signal to the laptop that it was finished. I've had this happen in the past but never connected it to the computer CPU running at a high rate to unplugging the printer. Thanks greatly for the help!

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Answer 3

OGELTHORPE

Level 9

57,305 points

Feb 7, 2016 11:08 AM in response to John (Silver Spring)

The printer symptoms that you describe are not that unusual, especially with HPs. I am pleased to hear the your MBP is back to normal. 🙂

Ciao.

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