Sorry for not getting to you sooner but that is in fact the freeze plug for the head and I am glad you found it. If you had water only in it then that is what it pushed out. However, it is odd that it feel back into the pan but I guess anything is possible so it is good you found it.
Thanks for using 2CarPros and continuing to follow up with us with updates as you worked through this.
Friday, March 5th, 2021 AT 6:46 PM