Hi Lee and thanks for using Just Answer.com
When the fans starting going are you doing anything in particular or is it just running loud all the time
Alright can you tell me the version of MAC OSx you are using on the machine and the model of the IMAC you have?
Thanks for that one second please
Also can you tell me how recently this mac was purchased?
Thanks for that and this problem just started recently?
Have you unplugged your mac since then?
This may sound simply but sometimes a power surge can get into the power supply and unplugging the actual power cable from the back of the computer for say about 20 - 25 seconds and plugging it back it can clear it out
ah ok one second please
Have you tried running a hardware test?
Ill provide the steps but could you tell me the version of OSX that came installed on your machine 10.4.x 10.5.x 10.6.x and let me know what the x number is
you can find out your current version by clicking the apple in the upper right hand corner and selecting about this mac
Alright do you have your OSX installation disc?
ok we will need that does it say a version number on the mac osx disc
I ask because the hard ware test tool is on one or the other depending on the version of software
Ok with 10.5.5 or later Apple Hardware Test is located on the Applications Install Disc 2 Please place that in your cd drive for right now
Then if you can please disconnect anything from the MAC like a printing or scanner just leave the monitor keyboard and mouse connected
Alright now please book mark this chat as the next steps will involve you restarting and going into the hardware tests so we wont be able to chat while its running you can book mark it or use this link http://www.justanswer.com/questions/461i8-fans-have-started-going-crazy-on-my-imac-have-tried-all-resets
Oh thats good
When you get to step 4 it should ask if you want to run the basic diagnostic or the advance i would run the advance as its more thorough
Lee I have to step away from my computer for a quick minute be right back please let me know how the test is going once its started be back in just a minute
while running the hardware scan?
Alright one second
Alright essentially that code is a sensor error, usually relating to the temperature sensor
Which in your case would case your fans to spin like crazy if the computer thinks its hotter than it is
Begin that its a hardware issue at this point there isnt much other trouble shooting we can do,One thing you can try is to get a can of compressed air and clean out the inside of the mac while a long shot sometimes it can be a simple matter of too much dust in the machine if that doesnt work however, I would suggest you should take this to an Apple repair center for checkout.
Yes they are a piece that can be replaced/fixed.
You are more than welcome is there anything else I can help you with
Alright well thanks for using Just Answer.com, If you feel we have solved your issue please click accept answer so we may close the question
Thanks again and have a great day
You are welcome thanks