What Is This Opening?

Passenger side, looking straight down into engine compartment.

Hole is located just above the frame, and directly below the coolant valve for that side of the engine block. Wet because I did a coolant flush and some of it dripped onto the parts below.

 

V6 or V8? Except for the location, that looks similar to where the throttle body bolts onto a V6.

 

I hope we are talking about cars.

 

V6

 

That's the upper oil pan. Not sure of its original purpose, maybe provisions for a pan heater, when the engine was designed at the turn of the century.

 

It's the big hole below where he drains the cock for the coolant, just under the dipstick tube