MacBook Air (MacBookAir5,2) running slow

Try resetting the SMC:

http://support.apple.com/en-ca/HT201295

Yes... tried resetting SMC to no avail.

I was going to create a new account to see if the issue is account specific and noticed that the fan runs high before I even log onto the original account.  

Creating new account, shutting down the computer and then starting the computer and using the new account did not help.

The computer was off all night and the fan races immediately.

I assume that I reset the SMC... didn't see any indication that it actually reset.

Exactly what OS are you using? You can check by pulling down the Apple Menu to About this Mac.

Also try resetting the PRAM by cold booting while holding down command-option-p-r until you hear the boot chime a third time.

Try safe booting while holding down the shift key.

Is the Mac still under warranty?

Not sure about the warranty.  Using 10.8.5.  PRAM had no affect either.

Safe Boot made no difference?


http://maccrazy.com/macbook-air-heat-fan-noise
You can check your MacBook Air’s fan speed with the free iStat Pro dashboard widget. iStat Pro will also measure the internal temperatures of your MacBook Air.
http://www.islayer.com/apps/istatpro/

If you have constant fan noise, and your MacBook Air is not doing heavier activities, your Mac’s System Management Controller (SMC) may be confused. You can fix this with a SMC reset.
SMC reset instructions for a MacBook Air are:
    Shutdown your MacBook Air (go to the Apple menu and choose “Shut Down…”).
    Make sure your MacBook Air has external power. Connect the power adaptor, if it isn’t already.
    Using the Air’s built-in keyboard (not a plug in keyboard or bluetooth keyboard), of the left hand side of the keyboard press Control-Shift-Option and on the top right of the keyboard, the power key at the same time.
    Release all the keys at the same time.
    Press the power key to start the computer.

Have already done an SMC reset.

Safe Boot makes no difference.  In fact, while holding down command-option-p-r and waiting for the beeps I could hear the fans ramping up.

You can check your warranty status by typing your serial number in here: https://selfsolve.apple.com/agreementWarrantyDynamic.do

Thanks for all your efforts Strung...

It's some kind of hardware issue:

4SNS/1/C0000008:Th1h--124

Thanks again.

That's the code for a failed temperature sensor. Were you able to determine if you were still under warranty?

NOT under warranty  :-/

Nuts!