So I know there is a way to get more heat out of my 12v. The stock thermostat is a 82c or 180F and no option to get a hotter one at dealer. So is there a aftermarket one available? or what is the trick to get more heat?
Work done so far:

Replaced thermostat, new water pump, Flushed cooling system, flushed heater core forward and backward, pressure test good: winter front on of course!! and yeah I have the heat control all the way hot on speed (3) of (4) the 3 speed seams to have more heat transfer through the heater core.

Thanks in advance to all who reply you guys and gals on this site are the best!!

 

It helps a lot if you run the heater in the recirculate mode instead of pulling cold outside air though the heater core.
Don't forget that in defrost the A/C is on, doesn't help keep things warm when it's below zero.

When it gets below freezing I don't think you even need a radiator with these engines unless you're towing. Just the heater core is enough to cool the engine.
Thus there is really nothing you can do to the radiator or stat to get the temps up.

 

Yep....running into the same problem...Going to try one more thing....A cummins thermostat instead of a aftermarket.If that doesn't help.....Heavier jacket...when driving..

 

Im freezing already...

 

Since I changed my heater core, I start to sweat.

 

Like Bill said, the recirculate mode helps alot. Windows fog up a little easier though. I just dress warm, long commutes I have to start stripping down.

 

On a long drive with a fully warmed up engine I've watched my temp gauge drop from 180 down to lower normal mark instantly just by switching from recirc to one of the other modes when the out temp is below 0 F.

Only reason I'm even switching from the recirc the setting is because it gets too hot in the cab but after switching it's too cold.
Found it better to just crack a window which also defrosts.

The real "problem" is just that diesel engines inherently run cold.

 

Thanks guys!!! I have seen also a Espar Heater in a 12 valve, and you could set it for 85 C or 185 F while driving the truck but that is a expensive add on, but a very good heater to have in cold climate. It uses very little fuel and would take only minutes to get the engine from cold to operating temp. Way better than block heater. It was like never cold starting your motor, it would be always warm, but I guess the oil would be cold. I will put that on my wish list!!!

 

Heater core.

Search for it and you'll find how to swap it out without too much trouble.

Had the same problem. Went through all the headaches you are. Finally found the time to swap out the heater core which fixed it. Backflushing didn't help at all. Even tried flushing with CLR.

Now its hot enough to get me sweating.

Good luck

 

Using the recirculate mode definitely cranks the heat up.... I also added in an oil pan heater which I have on a timer to run for a bit with the block heater every morning, between the two they help the truck warm up a lot quicker!

 

How likely is it that the hot water valve to the heater core isn't opening all the way?

 

Not likely at all since there isn't one.
Since the early '90s most vehicles have full flow though the heater core at all times, no valves that cause dead end plugging.
Modern vehicles use an air blend door to blend air that flows though the heater core with air that doesn't to control cab temperature.