Now that it is getting colder, I opened the valve to the heater the other day when I started the truck, because I wanted it to be at least a little warm(kinda hard with all of the holes and the heater motor toast) and it actually did stay warm, but I think that it had to do with the heat from the motor. But, after I turned the engine off, I touched both the heater hoses and the heater itself, and they were VERY HOT!!!!! So, as already concluded, something is wrong with you heating system.
