Bad my thermastat changed 2 days ago, it gets hot, but not overheating, what

First, verify that after opening up your cooling system that you have done a sufficient job of purging out the air pocket you have introduced into it. This must be done with a special tool, or carefully dealing with hot coolant at the cap. My guess is that the air pocket is leading to the "getting hot" condition. Alternatively - what was your original symptom? Perhaps getting into a diagnosis of your cooling system is a good idea. Is the cooling fan activating as needed?