I use a macbook pro 13'' early 2011 running OS X 10.9.5. My fans have been over working for no reason, no programs take up ram on the activity monitor. Beach balls and system freezes follow shortly after the fan starts running. sometimes the mac overheats then the fans kick in followed by the beach balls, but there is no app running that would cause it to over heat, it seems to happen by itself. I upgraded my ram from 4 gb to 8 gb, booted in safe mode, ran apple hardware tests, cleaned the caches with onyx and repaired disk permission but it still persists. any ideas on what this is and how to stop it?