Help - Water bypass tube leaking coolant

Have a leaking coming from the back of the block, im thinking its the water bypass tube under the valve covers. Having a hard time finding the fsm for this project, does anyone have it?

Looks like the seal is fipg?

The truck has been sitting for a few months since my diff pinion grenaded. Took the opportunity to fix some things and did steering and suspension and brakes. Never touched coolant or oil on anything engine related. Well I got all the parts in and went to do a brake test, which needs work too, and I have coolant that is oddly thick and a little oily. Had a mechanic buddy come out with a boroscope and best we could come up with is that the valley is full of partially dehydrated coolant, mixing with the valve cover gasket leak. That concoction is then leaking through the block off plate and down the back of the block and onto the bell housing.

I'll try and post pictures later.

 

On a removed motor, the leak is located here



I believe its this issue
https://youtu.be/2qExPX9wkCM?si=G8cIUtZBzZzqpk4f

 

The piece you circled is part of the coolant pipe and just a cover for the valley to prevent debris from getting in. A few things I can think of that will cause a leak there, lower intake manifold gasket, freeze plug, or the pipe itself corroded or has loosen.

 

@waldeeeeen
There is a good chance of it being the tube flange, more common than intake manifold gasket leak. Only way to tell for sure is to pull the intake.
https://www.tacomaworld.com/threads/coolant-gone-no-leak-visible.525167/#post-16740632