Posting this to help a buddy who bought his car not too far back. When he bought the car the car has never risen up to operating temperature like it is supposed to. First thing replaced was the overflow canister due to it being cracked. Then the thermostat was changed (wasn't even one on the car). Cooling system has been burped properly and the car came with an oversized radiator.
I plan on using a block tester to check his head gasket but haven't gotten around to it. Does anyone have any other suggestions or advice?

 

Car has also been throwing a code for the coolant temp sensor which was replaced also. After replacing it the car an perfect and got up to temperature like it is supposed to. A week and a half later the symptoms return.