jscrawford

I posted on here before with a question about my heater core. I have been able to get to the heater core through the glove box and feel the core. Is the heater core supposed to be hot to the touch when truck is at normal operating temp? My heater core is not hot at all and I think that may be the reason I am getting the cold air. Any help is greatly appreciated.

techrep

iTrader: (1)

Feel both heater hoses going into the fire wall.. if Both are warm at operating temp you have proper flow through the heater core. The actual heater core is contained inside the heater box.. so feeling the heater box may not result in a warm touch. You did not mention the year/model or motor of your truck, which if provided we could help you troubleshoot further...

jscrawford

Sorry about that. It is a 2002 with 5.4. Both hoses are hot although one does feel a little warmer than the other but that could just be where my hands were cold from being outside. I have tried flushing the core and had clear water come from the hoses. Not sure what else I can do without having to spend a fortune to have the heater core replaced.

jscrawford

Another thing that I noticed is there is cold air blowing when the truck is at normal operating temp and the blend door is fully open. I am puzzled as to why that would be.

techrep

iTrader: (1)

Like I told you .. if there is hot coolant in both hoses ..your core is good.. I suspect your blend door is not working correctly.

jscrawford

The blend door is working fine. I can see and feel the blend door working properly.

techrep

iTrader: (1)

If the feed line for the coolant that goes to your core is warm or hot at operating temp and the return line is the same, this means warm or hot coolant is running through your core properly and the core should be warm or hot to the touch just like the supply and return hoses.. it would be impossible to return warm or hot coolant from the core if it was clogged.

jscrawford

Both hoses are hot or warm at normal operating temp and the blend door operates properly as it should. So I am stumped as to why I get cold air instead of hot air when the heat is on and the truck is at normal operating temp. Thank you for your help, not sure what to try now.

JCR 56

If hot coolant is flowing through the heater core as it should, I don't see how it could be anything else but the blend door causing the problem. Are you absolutely positive the blend door is working? They can break where they attach and even though the motor is turning the door can't move.

techrep

iTrader: (1)

That's what I'm thinking but, I didn't want to call the man a lier.