iMac Suddenly the internal fan is very loud

We did have a lightning storm last night. Prior to that I unplugged the computer and there were no lightning strikes nearby. This morning the internal fan is much louder, pretty obnoxious in fact.
Nothing else seems wrong.

Any ideas? This is a relatively new iMac 27inch so I might lug it up to the apple store.

Mookiedog

Welcome to Mac-Forums mookiedog
Have you tried restarting the iMac since the problem occurred? Also does the fan keep spinning fast and loud or does it slow after a while?

Also if you could post your mac specs (year/model) and OS version (at a guess 10.6 but you never know )

Cheers

- Simon

nooisy fan

I unplugged the computer, waited and replugged it back in.

All is well. I think i will call applecare to find out what happened though.
Who knows.

Glad it is sorted now though!

- Simon

Install a fan speed monitoring app, there's one that sits on the top menu bar, iStat menus gives you all three fans (3 on my iMac)!
or widget iStat, you should see the speed increase when the noise increases.
Plus lots of other info.

v1.3
http://www.brothersoft.com/istat-menus-275403.html
or v 2.0
http://mac.brothersoft.com/istat-menus-2.0-download.html


Usually the fan(s) speed up when the iMac needs a bit of extra cooling, quite scary the first time you hear it.

Normal speed is around 1,000 rpm for all fans.

When you unplugged and waited, the iMac cooled down.