I flushed my heater core today. My heat got a lot better but still blowing a lower temp on drivers side. It is def. about 70% better. Maybe I need to do it again.

Also, what color is my radiator fluid supposed to be? Mine is like an orangey greenish color. Like its mixed or something.

 

Have you downloaded the Service Manuals from the links below to help you out?

 

bump.

 

I would do it again if it got better. The factory color is like a red orange. If its green someones added. I flushed my whole system and just put green in it.

 

You guys may want to see this thread

http://www.dieseltruckresource.com/d...d-t210483.html

 

I went through this last year. Same symptoms, no heat on drivers hot on passenger. I went through all the same things you guys are doing. Backflush the core, try to get all the air out... It would work after backflushing for about a week or two and then it would go back tot he same problem. No heat out drivers side and hot on passenger. I eventually just did the hard job and replaced the core. Worked great all winter after that.

Fast Forward to this fall, first time I go to turn the heat on and no heat out drivers side. YOU HAVE GOT TO BE F@$King KIDDING ME!!! or something like that came out of my mouth. I tried backflushing it and it worked for a week but now it's back to the same old crap. I even had a complete system flush this summer when the head gasket blew. Whoever owned the truck before me must have overheated it and popped a gasket and put some stop leak in it. I am going to do a prestone flush and backflush the whole system and hopefully it will clear it out. If not I will have to rip out the dash *AGAIN*.

 

So crucial, did you have to tear your dash apart and replace the core again? When you replaced your core, did you use a Dealer part or aftermarket? I've got the same problem with an 03 4.7

 

Reviving this issue...

Any permanent fixes?

Sometime in the last week my heater started to do the driver side cool/passenger side hot symptoms. Literally just started. Replaced the blend door just over two years ago. The heater core almost 4 years ago...hopefully that's what it is again.

 

Well i had the same problem with the heat on the passenger side only... So i looked around on here and followed some easy steps was goin to flush out the heater core but didnt have another hose to keep the fluid from leak out of the engine so i just switched the hose's top to bottom and now my truck is blowing HOT!!! air now so if any of you are still having that issue with the heat try that first seemed to work. Doing this also tells me that there is something clogging the coolent system probably just in the core i hope. Well I do have one question Would it hurt the heater core leaving the hose's swapped??

 

I personally don't see an issue, with the exception that if t was clogged, it may move that junk to the radiators or the engine.