Heater Core Performance

[Mopar1973Man]

Well Gang. I've been seen these goofy threads about people trying to figure out if a heater core is functional or plugged up. So since I took my truck to town for a job I figure I do the bench testing for the heater core to let you know what a good functional heater core will do. So measuring the vent temperature from the center vents with Bi-Level setting I measured...Fan Lo - 160*F roughlyFan Hi - 150*F roughlyOutside temperature - +10*FEngine Coolant Temperature - 193-195*FAs for the heater hoses they should not both be equally hot. I checked mine after driving about 6 miles from town stopped at a rest area and left the blower on Hi and felt both hoses. The hose from the head is very hot and you can only hold it for a short period before the heat burns your hand. As for the other hose that routes under the turbo in the steel tube that hose is warm but you can hold on to it for a very long time without even letting go. I see several threads where people say that if both hoses are hot the heater core is functional. This is wrong there should be a exchange of heat/cold with the heater core so one hose should always be cooler which is the return line from the heater core. If both hoses are equally hot then the heater core is not exchanging heat/cold and not flowing optimally. So I figure I'd throw this tidbit out there for everyone and hopefully help others diagnose heater core performance issue.