not that i looked very long but can you get 190-195 thermostats for 12vers. i know the 24v calls for one of these but cant be used. i agree with you a hotter stat would help combustion and power and also heater

i have the same problem as well im going to try and get one from cummins and see if that makes a difference

All of them do this. Cummins Thermostat #3934373 will eliminate the fluctuation, but it takes longer for the engine to warm up and the operating temperature is lower than normal. I just live with the needle bouncing around.

all of them do what??? a slight temp fluctuation can be normal but i think most of us have observed a condition where the therm seems to be stuck open or opening way too soon but so far...2 weeks and counting the stat i bought from dodge dont know part# but was in a cummins package has been working ok. i seem to remember something about the rubber coating on the back side coming apart and making the stat more sensitive to temp and this concern has been resolved with an updated part some time ago.

the only problem im really having is it takes to long for the thing to pop and once it does than everything is fine, ive seen it hit the hash mark between the 190 and the 230 before it opens

Mine gets around 210 before it opens and hovers around 190 fully warmed up. It does take a while to warm up, as mentioned earlier.

oh ok i wasnt quit sure to be worried or not since i just spent $2800 on a new fully loaded head with studs

Dodge TSB...

Date: Jul. 7, 1994

Models: 1994 - 2001 (BR/BE) Ram Truck

NOTE: THIS BULLETIN APPLIES TO VEHICLES EQUIPPED WITH A 5.9L CUMMINS DIESEL ENGINE.

Symptom/Condition:

The vehicle nay not warm completely, especially in cold ambient temperatures. This condition may be due to a thermostat that is stuck in the partial open position by debris in the cooling system.

NOTE: THE COOLING SYSTEM USED ON THE CUMMINS DIESEL ENGINE EQUIPPED VEHICLES PROVIDES THE CAPACITY AND PROTECTION OF THE HIGHER GVWR AND GCWR RATINGS AVAILABLE ON THESE VEHICLES. OWNERS SHOULD BE ADVISED OF THE NORMAL SLOWER WARM UP AND LOWER ENGINE OPERATING TEMPERATURES ASSOCIATED WITH DIESEL ENGINES.

THE COOLANT TEMPERATURE GAUGE WILL FLUCTUATE ON DIESEL ENGINE EQUIPPED VEHICLES. IT IS INFLUENCED BY VEHICLE LOAD, OUTSIDE AMBIENT TEMPERATURE AND EXTENDED IDLE TIME. THIS FUNCTION IS CONSIDERED NORMAL

GAUGE FLUCTUATION WILL BE NOTICED MOST OFTEN UNDER STEADY STATE (HIGHWAY) DRIVING USING THIS THERMOSTAT (P/N 4796869). PLEASE ENSURE THAT YOUR CUSTOMER IS AWARE OF THIS NOTE PRIOR TO RELEASING THE VEHICLE.


read more about it here...
TSB 07-07-94

Gauge fluctuation driving down the highway isn't normal BTW.

than what would it be