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hawkeye213

I need some help diagnosing my heat problem please

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When I turn my heat on it is just semi warm. I have searched the forum and checked everything. The Ac compressor kicks on and off correctly when the selector is turned. The air comes out of the appropriate vents when selected. The blend door works ( watched mopar video ) when the temp selector is turned. The big flapdoor over on the passenger side moves when the max AC is selected. The radiator was replaced and flushed 10,000 miles ago. New thermostat also. Temp gauge heats up to 190 and stays there no matter what I am doing. Both heater hoses going in from the engine side are the same temp and they are hot :evilgrin:. I pulled the glove box and can see and feel the heater core and the in and out pipes on it are both very very hot :evilgrin:. This heater use to get my truck unbelievably hot. I am inclined to believe its the heater core that is bad and I should just quit procrastinating and change it. Any thoughts would be appreciated.Thanks Rob

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if you are pulling alot of heat out off the core the oulet hose on the heater should be cooler than the inlet since you are taking heat out of the water. core could pe plugged up or the duct work full of crap or the fins in the heater core could be full of trash. mine needs the same treatment. i am also getting a little wiff of coolant every now and then. hope it make one more season.:pray:

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I agree with dripley. You're not getting a good flow over or through the heater core. The heater core is just a small radiator/ heat exchange unit.

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You can have both inlet and outlet pipe hot but have a heat core with 50% blockage. You would have cold spots on the heater core just like a plugged up radiator. I would try to flush it and see what happens. It's the cheapest and easiest thing to start with.

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Got the heater core changed out today. Man it gets really hot now.:evilgrin: Thanks everyone for the advice. Wasn't as big a pita as I thought it would be. I tried the flush deal but did not help. Even after I pulled it I flushed it again and had good flow thru it and thought great I pulled it for nothing. But like Mopar said it was partially blocked or something cause it really puts out the heat now.Thanks Rob

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So did you replace it or just clean it when you had the core out?

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IB I replaced the core. Dripley I got mine from Miller Radiator. It was like $60.00. It was a Ready Air 398313The inlet outlet tubes swiveled at the heater core. Which made the installation much easier. I highly recommend getting the swivel tubes. I did not have to remove the evap lines to do the removal. Nor did I have to completely remove the dash. Cant swear to it cause I didn't try it but I think if you just cut the tubes away from the old core and pull them out thru the fire wall hoses still attached and you get the new heater core with the swivel inlet outlet tubes you might not even have to remove the heater box from the firewall. Getting the old one out with the non swivel tubes was tight because of the evap lines and cannister being tight to the firewall. I did it by myself took about 4 hrs total. The hardest part was finding and removing the bolts to the heater box in the engine compartment. There is a video on youtube that helped alot. Not sure how to embed a link for it. Just typed in "google" heater core removal 2002 dodge ram 2500 and got the video. It will be nice to have heat this winter. Last winter was miserable. Like I said earlier I flushed my heater core when it was still on the truck and it seemed to flow thru great. After I got it out I hooked a hose up to it and it appeared to flow just fine and that was when I thought " great it really isn't the core. " Mopar tried to convince me it was the core last winter when I asked about this. I just kept thinking I have flow thru the core. Both of my heater hoses are the same temp "hot". it can't be the core. Thanks Mopar one day I'll learn to quit being so hard headed.:banghead:Thanks again Rob

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i saw some cores at rock auto with the same part #. differant brand though. also saw them on advance and auto zone with the same # differant brand. they did not sya anything about swivel connections. i need to do my evaporater too. been putting that one off. just dorve to my daughters house and have sprung a coolant leak in addition to my oil growing. got some new rv 275's for the second problem. was not expecting the 1st problem. i think my sunday is spoken for now. the coolant leaking form the front right of the engine. got here to late to be able to see it. oil growing coolant shrinking aint that lovely.

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Yes I am and it is true experience is the best teacher. But I really do appreciate yours and others guidance on this forum to solve these problems. Dripley good luck on your truck.

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I will tell you my heat now blows with some authority :gun:

Ok... Now you know my truck spends a lot of time in the dust and dirt roads of Idaho buy never had this problem... Why? Because any time I was to leave the pavement I would switch to MAX A/C, non A/C mode, or just turn it off while travling dirt roads. Knowing the A/C evaporator job is to sweat... It tend to collect a lot of dust on it so if you head my simple solution you'll never have to do this again...

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Thanks for the tip. I dont see dusty roads at all. One time i blew a hg and had oil all over the place. Another time i had the puke tube blow and cover the bay. Then i built a breather and put it on the pass side :doh: so i had a stream of crud flow. I have a hole under the hood for a scottys II intake. I ran the truck with that hole open for a wile. That ac picture i posted looks like a radiator/puke bottle problem if you know what i mean. Before i lowered the puke tube my radiator was covered like the ac in the picture. Thats my guess anyway. Oh yes i also at one time ran open breathers on the top of my valve cover :duh:

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They really work. The filter is as long as a 5 gal bucket. I all ready had the hole in the cowl because i knew it was just a matter af time until i found a scottys plus i tryed to make my own. I like the free air it grabs like the 70 ss chevelle.

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I have the same problem as the OP but I changed the heater core and I still don't get good heat like I use to. what I've done: changed heater core, flushed system, added cummins t-stat, replaced blend door motor shaft(wasn't broken),all 3 blend doors move(glovebox,2 under dash) Symptoms, now that its colder out, upon start up the windows fog up, the hot/cold regulator doesn't regulate so its either cold or hot no in between. water pump works well no leaks.so im at wits end! any input appreciated.

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i have similar problems as you. biggest differance is i have not tried to repair anything yet. heat is either full on or full off, not as warm as it used to be either. i dont have the fogginh problem though. did you reindes the blend door motor when you repaired the shaft?

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