Today we removed the stat. Looked in the radiator and there was an orange thing floating around. We were able to extract it and it was an orange rubberized or silicon glob about 1/4" by 1/4".


Hate to say it - But there could bee a 100 more of those plugged up inside your radiator core
Permatex copper silicone

First things first - Pull the radiator and bring it to your radiator shop or at least call them and see what they want to do

Original factory radiator ?
Has it ever been re-cored ? Professionally cleaned or boiled ?

Silicone in the radiator is not a good sign