04 4x4 hemi. had no heat going to work today(2 degrees...yay) then went to my dads to try and see whats going on. well we flushed the radiator with water then refilled it. didnt seem to work at first because it almost overheated, i pulled to the side of the road to let it cool. after it cooled, got home and my dad thought it couldve been vapor locked. so we ran it, poured anit-freeze in it till it stopped taking it. the upper hose that goes from the t-stat to the radiator is pretty hot, almost too hot to touch and the lower one that goes into the block is luke warm. my dad and i thought that was a little odd but i wanted to see what u guys think. i have heat now and its running within parameters. sorry if this is confusing, what im basically asking is how hot to the touch should the upper hose be that goes to the radiator from the t-stat? because mine is almost too hot too touch. and the hose going from the radiator to the block is luke warm at best.

 

The top tube is entry to the rad, so it's going to have all of the engine heat in it.

The bottom tube is dumping the chilled coolant back to the engine so it will be cooler.

How hot/cold each should be?? I really don't know, that's the best answer I can give.

Does your rad have cold spots?

 

not sure about the cold spots, when i drive it next i will check. just hoping the problem is fixed, if not i dont wanna figure out how much a new radiator is gonna cost if thats what the problem is.

 

when you flushed it did you use any chemicals or did you just flush it with water?

I would fathom a guess that the rad or heater core could be plugged, so when flushing there is actually a procedure to follow to make sure you flush everything, and you should grab a bottle or two of the prestone super flush or whatever its called.

You add the prestone cleaning stuff then drive your truck for a couple hundred miles, then flush, backflush, flush and fill.

Also if you aren't using the right coolant your rad WILL be clogged if coolant's have been mixed.

 

thanks for the info, i just flushed it with water. i will def give that prestone stuff a try.

 

To the OP.
Use the approved HOAT coolant. If you mix coolants, you can get a resultant sludge and therefore "plug" your system.
HOAT is approved by Chrysler/Mopar for our Aluminium heads and application etc.
The top hose will get almost too hot to touch and the bottom luke warm as your finding. So that looks good right there. The top hose should also feel very solid and tight and under pressure. But only when the trucks up to temp and the thermostat has opened, to allow hot coolant to flow into the top of the radiator.
The radiator is a large heat exchanger whereby, hot coolant goes into the top. Wends it's way downwards in the various tubes built into it. As it does so, air is blown across these tubes and fins which increase the cooling surface area, by either the engine fan and/or the movement of air across it as the trucks driven forward. This reduces the temp of the coolant, so that by the time it reaches the bottom of the radiator, the coolant temp is significantly reduced.
It's then fed back into the engine to start the heat exchange cycle again.
Hope this helps?
Al.

 

perfect abarmby, thats how she feels. i was hoping it was around the right temps, i just havent felt a hose that hot before but since the tstat is a 203* instead of the older('99) and GMC 185*(i think) it just made me question if thats as hot as it should be. thanks, looks like problem solved!