My 1998 Mazda B4000 recently it has almost become undriveable because it is leaking way too much. Leaks coolant even when the engine is cold. I can see the coolant gushing out but can't see where is the hole or how to access it. Here is the video of the leak. I just started the engine and it is cold.

It appears to be coming from the the gap between the thermostat housing and the timing cover. I am not sure if I can replace the thermostat housing in these engines. The engine is same as 1995 Ranger 4.0 I believe.
Is there any chance I can fix this leak? This is my daily driver

 

I gave the Haynes manual a look and the picture they had of the pushrod 4.0l V6. It didn't look like your video.
Given the location of the sensor/sender in your video, it looks like either the thermostat housing has sprung a leak, or the water pump itself (or its gasket) has let go.
How many miles are on your truck?
I wonder if a common weep hole in your water pump has let go.

 

It has 220k miles on it. Is it possible to replace the thermostat housing on these models? I have seen people replace the plastic ones on newer rangers. On these old models it looks like it is one piece.
Where is the weep hole on the water pump? How to fix it if that's the problem?

 

"Weep holes" are cast into the body of the water pump and when failed (leaking) it's simply time to replace the pump.
What their design function is, I do not know.
via RockAuto, Go here: https://www.rockauto.com/en/catalog/...r+outlet,10337

 

Thanks! I am going to try to replace the timing cover gasket

 

Weep hole allows water or steam to escape the water pump, otherwise the water pump bearings would be washed of lubricant.