WTF is this????

[rustynuts]

Originally Posted by Classic Boy

It certainly looks like the lower body of a oil pressure sensor but if it is, in my experience with the top missing engine oil should be pouring out that hole when the engine is running.

Your pic is normal for a snapped off oil pressure sender. It is common as it is easily snapped off if you hit it with an oil filter wrench while removing the oil filter. Yes that plastic piece inside is normal and holds the oil back.

[eksjay]

Like most things those sensors get brittle with age. My mechanic accidentally snapped it off during an oil filter change. You should replace all your spark leads and the top of your distributor cap. They will eventually become toast....