Hi,

I just got my truck on the road recently and even when it wasn't on the road it did this. First off let me list what i have done,

New radiator I took a radiator cap out of Dad's wrecked cummins which had a 15lb cap
pre boost screw in and it came with a banks #8 plate and the star wheel forward.
replaced intercooler


I am not sure if the temp gauge works or not. It just seems that i idle it for a little while then run it and it never gets me warm air. i put it on recirculate and that doesn't do much either. when i pop the hood and feel the radiator hoses they are warm as well as the rest of the engine. it doesn't put antifreeze into the reservoir tank but i am going ot fill that up. the radiator is full of antifreeze. Tonight i got it on the highway for the first time. I really ran it was running 80mph for a good mile or so and it still didn't put out any heat.

My dad is being a total jack*** so i do not have a garage to work in right now and it is freezeing out. I just want to see if this is a small fix or if i should find a 12 volt heater to use for the winter till i can work on my truck in the summer.

let me know because i felt really bad My girlfriend was sitting in the middle and she had a blanket on and i could still feel her shivering.

Thanks

 

First thought is a stuck open t-stat. If replacing it doesn't work, your looking at a plugged heater core.

 

so the thermo stat is right around the alternator by the heater hoses?

ill check it out

thanks

 

Cut a 1x2 to fit between your seat & the go pedal. I idle my truck between 1,000 & 1,500 rpm to get it warmed & put some heat in the cab. No diesel will slow idle and warm enough to get heat in the cab.
If both heater core hoses are warm it is circulating.
A cold front in the grill helps, too.

Instant warmth is best with a seat heater.

 

Sounds like your thermostat is stuck open it is in the housing right next to the alternator where the top radiator hose goes in. The original thermostats have a rubber around the base of the t-stat and it will come loose and get stuck in the t-stat. Just did one yesterday that was the exactly as you describe. Use only the cummins t-stat for best results.

 

I was running it pretty hard last night and it did not put out heat. I know the engine was warmed up because after about 5 minutes of normal driving the radiator is warmer and so is the engine block.

Alright i will prolly take a look at the T stat today if i have the chance.

Thank you

 

In five minutes of driving your radiator should not be warm. Your t-stat is stuck open and allowing flow through your radiator to early and keeping your engine cooler than it should.

 

Im not saying the whole engine and everything is warm. It is like 20* out and by warm i mean the radiator is not 20* like everything else on the truck.

I had never thought of the T stat as the problem but then again that was what was wrong with Mom's ford Explorer when it wouldn't put out heat.

Also i plan to block the grill off with these aluminum plates i have laying around. I was thinking only block 2 of the grill slats? or would there be enough airflow that i could block all 4?

 

It is simple to check take the top bracket off the alternator one 13mm end wrench and a 10mm take the two bolts off the bracket then remove the bracket. You may need to remove the clip from the wires that go across the top of the bracket. remove the three bolts on the housing and rotate it up to gain access. I place a large drain pan right under the housing an catch the antifreeze I don't mess with draining the radiator once you take the housing loose it will drain down enough. The engine lift eye is bolted on with the housing and it is kind of a pain alighning everything back up but should not take much longer than 30 minutes.

 

T-stat replacement instructions with pictures> http://dodgeram.info/tsb/1994/07-07-94.htm
Doubt it's your problem though, 12 valves run cold without a load even when the stat is fine.
My bet is your heater core is plugged.

 

Alright where exactly is the heater core located?

Today it was around 25 and i had the heat on recirculate running around town it did blow warm air. Not hot air like my gasser did. Also the temperature gauge does not move. if the T stat was bad would that lead to no fluctuation in the temp gauge?

Thank you

 

They don't run so cold you don't get any heat or move the gauge at least the three I have owned have always put out heat. Heater core is easy to check start truck turn on heater on high rev the engine and feel the heater hoses if one is hot and one is cold it is plugged heater core. If both are near the same temp that is not your problem.

 

Alright,

I picked up a T stat. i will heck the heater lines tomorrow to see if the core is plugged or not. it will put out a little bit of heat. tonight it put out enough to make me somewhat comfy ( i still had 2 shirts a flanel and a carhartt heavy jacket on )

thanks

 

That is a pretty good indicator that the t-stat is stuck open. I get plenty of heat from my 12 valve, even in below zero outside temps and I do not block the radiator. Still have the original heater core too.

 

ok

got called into work today 3" of snow and had to go shovel plow etc.

Maybe tomorrow if i don't get called in i will be able to work on the t stat to find the problem.

I am hoping that is the problem.