Laptop speed fan always at maximum.

Hello all! I have a laptop. An Asus k52Je and two months ago, I've reinstalled my windows (Windows 7 pro). I formated the disk and all was fine all was right until the next day when I was just seeing a movie and laptop fan started to work at maximum. I tried to solve the problem but I couldn't do anything. I bought a desktop pc and I abandoned my laptop. Then I sold my desktop and now I came back to my laptop. I decided to repair it. I've installed aida 64 and my Cpu temperature was at 88 degrees, but the temperature on cores was just right (34-36). I disassembled my laptop and I changed the cpu and gpu paste. I turned on the laptop and there wasn't any change. In aida 64 the temperatures were the same. I took out the cpu and ram and the put them back in and things remained the same... Also in windows 10 now, I get crash when ram became full and I get a lot of freezes. I tried changing the ram slots but that didn't make any difference. I reinstalled the windows and formated the disk 3 times and nothing... Even if I only get into bios after 15 seconds my fan gets at maximum and remain there forever. And now a want to ask you what should I do cause this problem passes me. Thanks in advance.