Hi and thanks for using 2CarPros.
I'm not sure which plug you are referring to. If it is the oil drain plug, it is under the vehicle on the oil pan bottom. It will be facing the rear of the vehicle. If you look through this link, it shows an oil pan and the drain plug.
https://www.2carpros.com/articles/how-to-change-engine-oil-and-filter
As far as a head gasket, too much motor oil won't cause that.
Let me know if that is what you meant or if it is something different.
Take care,
Joe
Jan 14, 2019 at 5:04 PM