Opening in top of engine?

[dmoccia]

I have this opening in the top of my engine (see images) that is missing something. It has threads and I can see oil in the opening, I don't know if there is supposed to be some type of sensor or plug in the opening. I attached two pictures: one shows the front of the engine and I stuck a chopstick in the hole to clarify its location. The other pic shoes the actual opening. Any help I can get to solve this mystery would be much appreciated!

 

[Alumarine]

How deep is the opening? Is it threaded? Does it bottom out?
Are you sure it isn't an indentation that oil has spilled into and filled up?

 

[Watermann]

I see from your other posts that this is a 3.0L A threaded hole without any signs something was mounted there. Since I don't have a 3.0L I would have to guess it's for a bolt on option that you motor isn't equipped with. Soak up the fluid in the hole with a towel and see if it returns.

 

[wrvond]

Because I'm such an awesome guy (modest too!), I went outside into the dark and looked at my 3.0L for you. The hole in question is threaded and dead ends. No idea what it's for. Here's what it looks like without oil in it:

 

[dmoccia]

Thanks guys!