I have Ford E150 5.4L, in rear passenger side of engine where upper intake manifold meets the engine block, there's a missing plug/part/cover in this corner where the two meet. There's no wires connected to this part, but is a place for a single bolt and next to it is have exposed open valve, and gasket is visible on the bottom engine block.
I thought it was freeze plug, coolant valve, temp sending unit, but, nobody at 2 autozones could figure it out, even ford isn't 100% sure. At first, I though part of the upper manifold broke off exposing a corner of the engine block valve, however, isn't the case, whatever was there broke/blew off due to pressure or likely due to the pin hole coolant leak in my water metal by pass hose right above it.
Antifreeze will leak out of this valve, so it's a water/coolant port of some type, and whatever was covering/coming from it has popped off.

 

It's called a gasket.

O.k , stupid answer but I cannot see enough of the engine to tell...

 

actually , another forum member mentioned that is the way it was built from factory, so, I'm looking into that scenario, it kinda makes sense since motor never had been worked on, just looked like something might have blew off, but engine parts just don't blew/break off hardly (lol) if you really think about it.

 

That's correct.
How about pressure testing the cooling system once you have it back together?

 

If I'm not mistaken, that's just the way they looked. This was the same gasket from side to side, just turned around so the specific holes lined up.
The heads WERE made with different passages that sealed up the required spaces.
However, these holes in the picture are not seen on cars (because it's really hard to see back there), and are on the econoline with it's removable doghouse.
In the front of the heads/intake, these are the coolant passages. They aren't used in the rear. Therefore, you can use the same gaskets for both sides and save 10 cents for every gasket. And if you're an engineer, you get a raise. And if you're a vice-president, you get a promotion. And if you're the CEO, you don't care, because the tecnician still has to replace it for warranty time.

 

Greasemark....yup, that's exactly the case,

After rechecking, this port hole actually goes thru and opens at the bottom of the engine block (hole runs 3" long or so), I poured some coolant and would you know it, it came right out the bottom hole. This now confirms without a doubt that the block/manifold were manufactured this way and yes, if you can't see the engine rear you would never notice it. But, I must admit, it certainly gives you a shock when it's first noticed.

Thankyou all...