MacBook mysteriously crazy fan speed

My MacBook has been acting weird lately. Its fan speeds just go up to as high as 5k while I'm surfing the web (Firefox), 3k on average. No embedded flash videos, etc. I've searched the net for solutions and none of them work for me. I tried checking my Activity Monitor, and the app that uses the highest CPU % is Firefox at 12% at most. I happened to see Quicksilver go up to 97% for a second then it disappeared. I tried looking for any hidden Print Jobs but I had none. I have 1 stuck process according to Terminal, but that's basically it. What could be the problem? I have a 2.4ghz white MacBook, 10.5.6.

 

Is there something blocking the fan/vent from circulating air? There might be some dust, or some particles that are not allowing the proper air to get around in there and cool it off. There might be something near your CPU that is only triggering the fans when something CPU intensive occurs.

 

Is there a way that you can check the CPU core temperature?

 

iStat Pro could do that for you, as a dashboard widget or as a menu bar option.

 

which macbook version do you have? the intel x3100 macbook runs incredibly hot and ive noticed that the fans are frequently on... things to consider: hot gpu, poor thermal paste application, something blocking the vent/dust (as suggested).

 

My X3100, 2.4GHz Pennryn sits in the high 30s, low 40s when just web browsing. HDD temps are usually in the mid 20s. iStat pro won't tell you the core temp. You need an app called hardware monitor for that.

 

that's interesting. maybe it means that the one ive had experience with had poorly applied thermal paste...

 

Colton: There seems to be nothing blocking the air vents. Besides, the fan speeds go haywire even when I'm using Firefox only. CPU A temp is 60deg on average, at 1800rpm.

fastrandstrongr: WHat do you mean by thermal paste application? I tried searching the web for any other causes, such as ATSServer going crazy, font cache problems, etc. They don't seem to be the causes.

joshuaLX: We have the same model, but my unit is typically 60degs (accdg. to iStat Pro) on average. Why is that?



--> This is from when I'm only surfing the web, at 1800rpm.

 

download smc fan control (a simple google search will give you a download location) and force the fans into 2000rpm. I have 3 profiles: default(2000rpm), medium(3800rpm), high (6200 rpm).

 

apple has been known to slather on thermal paste on the processor. its not an efficient way - nor the correct way - to apply thermal paste and it will cause your machine to overheat.

 

Try resetting the SMC.