RE: Heater won't warm up
I have exactly the same problem and would like to know if you already fixed the problem.
Yeah, exactly the heater hoses run from back of the engine block to the h core and the returning goes to the upper side of the radiator.
I just loose the returning hose and with the engine running checked if was water coming out, but the hose was all the time empty and the hose that is coming from the engine block feels so soft when engine is running, then looks that nothing water is coming from the engine block. I have been trying to remove that hose but is very complicated since is in the upper back of the engine with minor space to work on it. Same time i have been looking for a heater valve but doesn't seems that exist that valve in the system.
Any ideas to remove the back hose where is installed the valve?
My car is a Silverado '94 ext cab with 5.7