Engine/Transmission (1998.5 - 2002) help me figure out my cooling system problem

[getblown5.9]

low heat in the cab unless im getting on the loud pedal hard to really make temps stay at 190-195* but if i cruise and truck runs 160* the air from the vents is cool. temperature fluctuates every minute or so with the t-stat opening and closing.

put a new t-stat and rad cap on it, thinking maybe i wasn't getting proper flow or pressure.

here is the funny part, i can take the truck out and drive it, get it up to operating temp, nice and hot. come back to the garage and can stick my finger in the coolant at the radiator cap and its maybe 80* on that side of the radiator. but if i touch the drivers side where the top hose comes in, its hot enough to burn you pretty bad.

how can my radiator be well over 100* difference in a matter of 24" from one side to the other?

also, when i get the truck above 2,000rpms, i can hear the water rushing thru the heater core, like a high pressure nozzle shooting water. im thinking there may be some blockage in the heater core.

what could be my problem

 

[Cummins724]

Sounds like you are vapor locked.

 

[JFaughn]

1st , what claimat are you in , then where did the t-stat come from ?
I've seen a lot of bad stat's from the avarage parts house for yrs.
From your discription I would double check the level in the rad. & res. , you should not hear the heater core unless theres an air pocket , the blockage maybe , but that would be under other conditions [ older truck with high miles , some problem in past , putting contamination in the cooling system ] .
If your in a cold climate , then a winter front , cardboard ect. ,
I also remove the fan for winter , we just had -37*F 2 wks. ago ,
Then theres the reputation of the Cummins , they do not run very hot ,
Just some ideas ,

 

[getblown5.9]

its a stant brand t-stat from pep boys, it had a 5 month old cummins/dodge replacement that was put in when i did the o-rings and headgasket. back in september when i blew the HG, the system was full of oil and i ran water and cascade thru the system, then flushed it out, ran just water for a week, flushed, water for another week, then finally i flushed and put 50/50 in.

also i am running a piece of cardboard in front, with a 24 inch hole cut out for the fan.

 

[Texas Diesel]

Dodge has a fix for the whooshing sound. It involves replacing the fitting on the head to hooks to the heater core. I think it is some sort of check valve or flow limiter ???



I dont know the TSB number but might be able to get it if you need.

 

[getblown5.9]

that was for 99 and earlier trucks i think. mine is an 02 and never made the noise before i did the headgasket.

is the heater core like the radiator with the tubes and fins inside with endtanks, or is it just copper tubing with fins. i want to do a reverse flow flush on the heater core and see if maybe some crud or gasket material got sucked in there.

last thought-i replaced the heater hose with unmolded rubber hose, its very flexible. im wondering if maybe its pinching shut somehow and causing a restriction into the core