After resetting the SMC on my iMac, then taking it to the Apple Store for diagnosis (they found nothing wrong, the fan on my iMac still intermittently runs loudly for 2-3 minutes for no apparent reason
You need to reset the SMC several times back to back with all peripherals disconnected and then re-test. Please do this and let us know if this helps.
Also, when posting at the very least we need to know the iMac you have (year & size) and the version of Mac OS installed.
Seems to be working. No fan noise for an hour! Thanks!
Your welcome.
fan on iMac runs loudly much of the time with no reason
