What exactly happened here?

 

Coolant. Pouring from the back. Valleys full but can't find the leak

 

Probably from your intake u just did. Maybe it was cracked lol

 

I looked it over and it wasn't from what I could see. Going to pressure test it tomorrow.

 

Time to put in the lightning intake...

I forget if the manifold bolts are tourqe to yield. But hopefully you did the correct tourqe sequence. I bet the water pump hose in the valley is cracked or got knocked loose. That's fairly common

 

That's what I looked for because I knew they were problematic. Mine was in great shape. Kinda annoyed. It may be supercharger time since my vac lines need replaced
It also acts like it only leaks once the thermostat opens up. Short trips right after cold starts it doesn't leak

 

Sounds like the moment is right.

 

If the block cavity is filling w/coolant, - usually it's either the by-pass fitting /vac cap is leaking (just before the heater core hardline ducks behind the passenger side head) or it's leaking at the double O-rings right behind the water pump.

Ford updated all that with a good fix that I haven't seen fail yet, BUT, only the reman engines received the upgraded heater core hardline. There's a picture of it in one of the Haynes or Chilton manuals....If you own one lol.

BTW, -the HCHL by-pass by the firewall is there for the trucks that have the Cold Climate system package.

 

Oh yea, if there's any residual oil left on the heads or intake gaskets when you install the intake, - it will leak for sure. Also if you don't stage tighten the intake down, - (at least 2 stages) - again they'll leak for sure....Right out the front water jackets lol.

If you have pits in the heads at the jackets, - they must be fill with an aluminum filler prior to gasket installation.

In case you weren't aware.

 

One other thing, - you have the upgraded composite intake, - new and improved formulation for 03.

So, -It ain't suppose to crack!