Hey everyone, new to the forum but have had my 05 G6 for about 2 1/2 years now. Trying to get it ready to sell cause my oldest son has special needs and as he has gotten older he needs a special car seat that is just way to big for this car so I had to get something a little larger. But the check engine light had come on and I figured out the items I needed to fix so I've been working my way through those. Not a mechanic but have just grown up with my dad working on our cars and just learned by watching and helping him. But I was replacing my thermostat this morning and noticed this piece was broken off. It's obviously been broken before because in the pictures you can see whoever it was tried to fix it with gorilla glue. As dumb as I feel having to ask, I just am not sure what this is. But I figured someone here would know. Thanks for any input!