For the past few months I've been doing quite a bunch of heavy load things on my Mac. So I wouldn't worry about the Fans running at full speed. Recently I've started to do more casual things. I've noticed when I turn my computer on the fan starts running at full speed. My computer's temperature is usually about 170 (150-220). The fan stills runs at full speed even when the total CPU usage 4% and with a low GPU usage. The only way I can turn my fans down is to open Macs Fan Control and set it to "auto". I have installed some fan control apps in the past but I uninstalled those. Could it be possible some leftovers are messing with my fan?
EDIT: I have removed all leftovers and the problem still continues
Best Answer
You mention that you use iStat Menus for temperature and a separate app for controlling the fan speed. iStat Menus has functionality to control fan speed by itself—make sure that you do not have the fan speed set to maximum in iStat Menus as this will override OS X unless another app then overrides iStat Menus.