the bottom side of the top hose should be a full 180*, too hot to hold onto.

i don't know. water pump is a pain to change. i wouldn't do it unless i could either prove it was bad, or just ran out of all other options. it seems like you're either not getting good coolant flow, or there's not enough cooling going on in the rad.

VWandDodge has something sort of like this going on when towing. i think he's replaced everything in his cooling system, including water pump, and its still going on.

you might try this. careful, its dangerous.
loose/remove clamp at radiator on top hose, slide hose on/off radiator a couple of times to make sure its not stuck. **** important - remove radiator cap so as not to build up any pressure. ***

crank truck and let idle and bring it up to your hot temperature. careful of fans and belt, and using some towels so as to not get burned, slide the top hose off the radiator. is the water pump pushing water out. careful - that coolant is hot, whatever temp the gauge says. observe what if does at idle. have an assistant rev the motor. does water flow increase ?

 

my truck was running hot as wellman, it was around 210-230. If i came to a stop it would climb up, but if i reved it or started moving it would cool back down. Ive changed my fan clutch, new rad cap, new 160 tstat, and rad flush at a shop, its better now, but it will still climb when i come to a stop.


sorry for hijacking your thread haha.

 

im figuring that my water pump is weak? and with the restriction of the tstat it cant overcome it very well and its just pushin a little bit out


earshot- dont worry, ill just hijack one of yours someday j/k, no prob

 

i don't know. there's really no explanation for why it would be "weak". its just an aluminum impeller on a shaft. it doesn't wear out, it doesn't shrink, it doesn't rust out, it doesn't corrode. the only things that generally go wrong with water pumps is the seal or the bearing. not the impeller and not the shaft.

it might start slipping on the shaft. that's possible, but then you'd get little to no flow - and your truck would have continued to overheat when you had no thermostat at all.

now, here's a possibility. you said your lower radiator hose spring was in pieces. its possible that there were other pieces that got sucked up into the water pump, and they might have broken off some or all of the impeller vanes. that would result in low flow and be visible by checking the flow coming out the top radiator hose. hmm, since i've got no better ideas, i'm going with this one. check the flow at the top hose.

 

a little safer way to test it and not get burned is this - remove radiator cap and stick the water hose into the top of the radiator. disconnect top hose at radiator. crank truck and let it idle. while its cold, you'll have no coolant coming out of the motor. as the t-stat opens, you will. when that happens, turn the water hose on enough to keep the radiator full. observe coolant flow at idle and at medium rpm's.

there goes another $10 worth of antifreeze.

 

alright i guess i will do that when i get the chance

 

Any news on this? I am having an exact same problem, and I have done everything but the water pump or the radiator...

 

nope.....still the same.....i ended replacing the waterpump cause it started leaking and messed the fan up and put on an elctric fan and its the same....hasnt really been bad enuff to worry about i dont guess, im figurin that my rad is partially clogged

 

mine turned out to be the radiator, put a new one from NAPA in and its runnin like new. only cost about 200 ucks if i remember correct

 

last fall and all winter long i didnt have a drop of coolant in my 94 1500, probably never got over 210, and once i realized it didnt have any coolant, i replaced the water pump. The housing was cracked, and the **** just sprayed out of it! So with that done, figured id spring for a new tstat, got the 180 at napa, and it rarely touches 200 now, and i feel a lot better knowing that! I just dont get what the problem could be for you. All thats left is the radiator i suppose.....