In my 82 pickup the heater can barely keep up unless the engines at 3000 RPM. I have found some Aux. heaters that use engine coolant to heat up. Wouldnt that be pointless? If its heat source is the same then the overall output temp would be the same too right? I dunno but i need to buy a new heater core or an Aux heater unit.

Thanks for any answers.

 

Is your engine up to temp when the heat isn't keeping up? Mine had a bad thermostat so the coolant was circulating all the time, keeping the engine from warming up so no heat. Cheap & easy to fix too.

 

Thermostat is a possible, also might check and make sure your heater control cable is fully opening the valve when you slide it over to call for heat. As old as your truck is, if it has never had the heater core replaced, I bet your heater core is getting plugged up and not allowing good coolant flow through the core.

 

Ok i will check the thermostat, cable, and if that doesnt fix it i will rip out the core. the Engine temp drops a little after the heater has been on. Its ok during the summer nights when you just need a little warmth, but during the winter i keep a few coats stashed in my truck.