Overheating laptop Asus X553m

Mar 16, 2021
Hello, so I found this old laptop and I turned it on and it was really slow. So I decided to change from hard drive to ssd and switch from 4gb to 8gb of ddr3 ram.
When I turned it on it started overheating and the fan started to spin like crazy. It was like 80-90 degrees.

So I opened it again to switch thermal paste on chip.
When I turned it again same thing happened it dropped just around 10 degrees like it was still aroud 70 degree .

After the windows boots on it need like 3-4mins it gradully brings the temp to the max over that few mins and the fan starts spinning crazy. Like at the beginning its silend and at the end like a plane.

Anyone knows is there I something might did wrong while opening that laptop ?

Laptop is Asus X553M. Specs:
Processor : Intel Pentium N3540 with Intel HD graphics
RAM: 4GB DDR3 1333Mhz
SSD: 240GB Patriot Burst Elite