Help!!! Macbook fan not turning on!

Hello there!

I have a problem with my macbook fans. The fans do not turn on until the computer has been running at 80°C for 5 minutes and only then my macbook only runs at 3000 revolutions. The fans idle is 2000... I know this because I have an application from the mac app store called temp. guage and that tells me temperatures and fan speeds.

The fans to both of my brothers macbooks turn on once the computer is about 60-75°C and it turns onto 6000 revolutions and their idle is 2000 revolutions . Could it be that I have a macbook and not a macbook pro? Or could there be something wrong with my fans?

When I got the computer about 1 year ago the fans turned on a lot but I didn't have this app for various reasons but I could hear the fan turning on. I know that the fan back then was faster becaue i could heat it and when the fans now are at 3000 I can not hear it.

Could a connection be loose - I have never opened the back case but I carry the macbook a lot with my in school? Could there be so much dust on the fan that it tries to spin faster but it simply can't? Could it be the grease on the fan? can anyone help me narrow my decision? Do I need to replace my fan?

Today I was at the apple store and I did a diagnostic test. The only problem was with my speakers but I did not notice that. Point it the fans were all right in the diagnostic test but in reality the fans are not all right...

Someone please help! This is a desperate problem my computer keeps on shutting off because it gets too hot.

Category: Power

Thanks in advance!

Avranius