Metallic ticking noise from the MBP I have an early 2011 MBP and opened it's back more than once, to replace RAM, HDD and 2 weeks ago I installed an SSD. For some time already I hear a faint ticking noise from the body when the laptop is running, laying on a flat surface. First I thought it's the HDD's head hitting an end position, that was part of the reason I replaced it. Now with the SSD I still hear the noise sometimes. 

I could not figure out what it depends on, sometime it comes and I hear 1 tick in irregular intervals form 1 to 5 secs, sometimes I hear a lot short after each other, and some other times the noise is not audible at all for hours. 

I have the impression that the noise comes from somewhere below the trackpad, around the place of the HDD, now SSD.

Any idea what that could be?
It's certainly inside the MacBook Pro. You should check this out : https://discussions.apple.com/thread/2387469?start=15&amp;tstart=0

This should fix it, helped a lot of people. Click Here

So it happens when you have to apply conductive grease. It's certainly a problem with the CPU I think. After following the steps, your machine shouldn't make any sound.