I found a significant coolant leak around the transmission and oil pan which I traced to a location on the back of the engine drivers side. It leaks without needing to turn the engine on. Pictures show pretty clearly where it’s coming from I just need help identifying exactly what the part is that’s leaking, and the easiest way to repair/replace.

When I fill the radiator the leak sprays out from the engine towards the cab

Another shot

Stuck my phone behind there and captured where the leak is coming from. Is the leak coming out of the engine block? I haven’t had any luck finding a diagram showing the coolant path through the engine to figure out exactly what needs to be replaced.

 

Due to the reflections, it appears to be leaking on to that spot, not leaking from it.

Unless the image is not correctly oriented to 'up'.

 

Looks like a rusted out core plug(AKA freeze plug)

Core holes are used to remove the sand after block or head is cast, the holes are then machined and a metal plug is inserted to seal it, these plugs can rust out if coolant is not changed every two years

There is a core plug at each end of a head, looks like this: https://www.enginepartstore.com/imag...ry/v406b-4.jpg
The gold colored part

If you can pry out the old one you can replace it with a rubber expansion plug of the correct size, like this: https://m.media-amazon.com/images/I/..._AC_SX355_.jpg

Normally you remove the old one and then POUND IN a new one, the metal ones are CHEAP, lol, but in this case you can't pound in a new one because of the location, unless you want to pull the head off.................
Anyway the rubber ones are inserted into the hole and tightened with a wrench, which expands them to hold tight and seal the hole
They are better than the metal ones but cost alot more so car makers don't use them

No, I don't know the size

Another not common but known leak point is at the corners of the lower intake manifold
Coolant travels from one head to the other in passages in the lower intake, so all 4 corners have coolant passages, any of which can leak

Picture of the bottom side of 4.0l lower intake manifold: https://www.picclickimg.com/d/l400/p...tar-Ranger.jpg
You can see the 4 coolant passages, one in each corner

 

Thanks for the reply, Ron I think you nailed it. Good to hear about the rubber expansion plug, I was worried the whole engine would have to come out to get another plug in. I'm hoping the rubber plug can hold against the pressure of the coolant system. Warm climate so at least I dont have to worry about freezing/expansion. Ill post some pics of the process.

 

Yes, it will hold fine

That's a common Myth about "freeze plugs"
I am sure it started off 100+ years ago by a mechanic telling a joke/fib to a customer on what these plugs were for, lol
Like a mechanic explaining what a Muffler bearing is for, or being low on turn signal fluid and having to "top it up"

These core plugs WOULD pop out if water froze in the block or heads, but it wouldn't "save the block" or head, they are not located at low points, so if there was a hard freeze it could crack a block or head
So these are NOT a safety feature, never were
They are holes to remove the SAND after the block or head is cast with molten metal, and sealed up the cheapest way possible

 

You mentioned that there are freeze plugs in the head. How many are in the block and where are these located? I know there are 2 on the back of the engine. Are there any in the front of the block?