Do they make different temp thermostats for our trucks? What is the highest temp I can put in? Very little/no cab heat. Levels are fine and circulation is fine through the core, blower works fine.

 

last year when I was having trouble with my truck, I read a TSB at the local Cummins shop about the t-stats.. it also discused the importance of keeping the engine within its design operating range( temp-wise) of 180-205* IIRC.
Too cool is bad and too hot is worse.....
I think I woud try to figure out what is wrong, rather than risk compounding the issue...
You could have a t-stat stuck open, or soemthign along that line...

 

They just don't seem to get very warm without a load on them. If a stock T-stat won't get warm enough to open why would a hotter on make it any better?

 

went to cummins and replace mine it was a 190 deg thermostat with the bleeder thing on the side and theremstat was 12.00 and easy to replace

 

Well, if you have a 160* in, things will be cool in the cab, if you put in a 200*, things should be warmer in the cab. The hotter the coolant is running through the core, should be hotter in the cab.

I didnt know what the stock t-stat temp was, or if I could increase the temp to see if it helps.

 

I just went through this, put in the Cummins part and all. Saw basically no difference, maybe warms up a little faster. Yesterday I let it run for 1 full hour and the top rad hose was still ice cold. I changed the oil and it wasn't even hot. I have about 80% of the rad blocked. I am convinced thye won't warm up unless they are loaded.

 

Good point!

 

The stock one is 180*

If the engine is cold enough for it to be closed still what difference is a 200 going to make?

 

Take a look at the OEM and NAPA upgrade heater core in my gallery. More heat at less heat on the gauge. At 140* water temp I have hot heat blowing from the vents with the bigger NAPA heater core.

 

Do you have a part# for that heater core? Is it a major PITA to change?

 

I geuss I am assuming that the engine would continue to build heat. But, we all know what happens when you assume. I don have another stock heater core, but dont know or think that would make any difference.

 

Have you tried the air box clean out that's in the sticky?
Maybe your just getting air thru half the heater core or some thing.

You said your heater hoses were hot on both sides..............with the fan in high, one of the hoses should be cooler if the heater is removing heat.

Flash

 

When I restored the truck, this was also one of the things that were assembled with care. It was all cleaned and wiped down before installation. Maybe another core would help, I just hate the thoughts of doing all the work and then have it not help, but if I have too.....Thats why I am on here asking questions to see what my fellow brethern have experienced.

 

IMHO you'll get more results from swapping out the core than from putting a differetn t-stat in.
I cant see how that will help ya.......

 

Another question for you all. Does the rad fan turn all the time, or does it only turn when the temp goes up? I remember from one of my old first gen diesels, when I started it up, I could hear the fan running and then it seem to shut off. Could this have anything to do with my problem? If the fan is running all the time and it isnt supposed too, thus cooling when its not supposed to, = cooler temps?