Thank you for you responses, APT403 e C_deck. I waz a bit worried, but i've noticied that it's a glitch too. When I turn fan 3 to 35% (not more not less, 35% exactly) on Coretemp the temp gown down to 37ºC. And once it hit -42ºC, followed by 6ºC. This is on 28ºC ambient and all air cooled.