New To Mac-Forums?

Welcome to our community! Join the discussion today by registering your FREE account. If you have any problems with the registration process, please contact us!

Get your questions answered by community gurus Advice and insight from world-class Apple enthusiasts Exclusive access to members-only contests, giveaways and deals

Join today!

Start a Discussion

Mac-Forums Brief

Subscribe to Mac-Forums Brief to receive special offers from Mac-Forums partners and sponsors

Join the conversation RSS
Apple Desktops Discussion of Apple's desktop machines including Mac Pro, iMac, Power Mac, and mini

Imac CPU Fan speed issue.

Post Reply New Thread Subscribe

Thread Tools

Member Since: Jan 12, 2010
Posts: 1
Pmeth is on a distinguished road

Pmeth is offline

I have a late 2008 Imac 24" - 2.8 GHz Intel Core 2 Duo / 2GB 800MHz DDR2 SDRAM. I am currently running OSX - 10.5.8.

The problem i seem to be having is with my CPU fan. It seems to be running at full capacity whenever i run more than one application. The response time of the desktop doesn't seem to suffer at all its simply the buzz and whir of the fan that is annoying.

I've have SMC fan control running on the system and the fan usually runs at a constant 3000 - 3500 RPM.

I've done some research online and from what i've found is it could potentially be the heat sensor connected with the actual fan that is making the fan run at a higher rate of speed?

At first i thought it might be SMC and maybe a corrupted file, but i've since removed and re-installed the program. I've tried resetting the fans (removing the power cable) and turning the system back on, this is a short fix that doesn't really solve any problems long term.

My question to you is, apart from playing my music loudly to drown out the noise, what if anything can i do? Has anyone had this issue before? If so how did you fix it?

I do not have an extended warranty with Apple.

Any advice feedback or places to look for answers would be greatly appreciated.

QUOTE Thanks

chscag's Avatar
Member Since: Jan 23, 2008
Location: Fort Worth, Texas
Posts: 44,748
chscag has a reputation beyond reputechscag has a reputation beyond reputechscag has a reputation beyond reputechscag has a reputation beyond reputechscag has a reputation beyond reputechscag has a reputation beyond reputechscag has a reputation beyond reputechscag has a reputation beyond reputechscag has a reputation beyond reputechscag has a reputation beyond reputechscag has a reputation beyond repute
Mac Specs: 27" iMac i5, 3.2 GHz, iPad 3, iPhone 5c, 3 iPods, Yosemite

chscag is offline
It does sound like a wayward heat sensor. The normal operating fan speed (RPM) for your machine should be in the vicinity of around 1800 to 2000 RPM at idle. Of course as the load increases on the CPU or from HDD access, the fan speed will increase to keep the temperatures from rising.

Your iMac is not easy to do any self work on as the entire display assembly must be removed in order to get at the inside of the machine. An iMac is actually built as a vertically standing notebook computer.

You might want to visit iFixit: Apple Mac, MacBook, iPod, and iPhone Repair Parts and look at the step by step instructions for opening up your iMac and replacing components. There's no guaranty that it's the heat sensor, so keep that in mind.

QUOTE Thanks

Post Reply New Thread Subscribe

« logit 7.2 for G4 | G5 iMac stuck in sleep »
Thread Tools

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts
BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are Off
Forum Jump

Similar Threads
Thread Starter
Last Post
Need to know how much RAM your Mac can hold? iLaugh Other Hardware and Peripherals 6 12-13-2009 01:49 PM
imac 20" core duo CPU upgrade? grillbiller Other Hardware and Peripherals 0 10-16-2007 04:35 PM
iMac: Ejecting Devices & Network Speed muraii OS X - Operating System 0 10-13-2007 02:30 PM
imac macos 9.2 issue....... tgg Apple Desktops 2 05-01-2006 11:52 AM
Upgrading iMac CPU imstillatwork Apple Desktops 3 02-12-2004 06:22 PM

All times are GMT -4. The time now is 10:38 AM.

Powered by vBulletin
Copyright ©2000 - 2015, Jelsoft Enterprises Ltd.

Welcome to

Create your username to jump into the discussion!

New members like you have made this community the ultimate source for your Mac since 2003!

(4 digit year)

Already a member?