Engine/Transmission (1998.5 - 2002) Simple coolant question

[Bobalos]

I have a 99 3/4 ton 24V motor, what is the coolant temp supposed to be? IOW, what T-Stat is in the thing & where do they normall run?



Sorry for the easy question, but I searched & did not find the answer to this. the manual says 0 - VERY hot is OK, but what is normal for these motors w/o load & simply cruising @ 70 MPH?



how much would one expect the temp to go up with a 4000 Lb car & a 1500 Lb trailer?



thanks mucho

Bob

 

[Alan Reagan]

I believe the 99 is a 190 thermostat. My 2001 is a 190. It runs at 190 whether I'm towing or empty. By towing, I mean 10K. It will climb above 190 just a little on the hills but if it goes much over, the fan will engage and cool down pretty quickly. Some have changed to a 180 but Cummins South recommended I stay with the 190 when I changed mine recently at 100k miles.

 

[thejeepdude]

Originally posted by Bobalos

I have a 99 3/4 ton 24V motor, what is the coolant temp supposed to be? IOW, what T-Stat is in the thing & where do they normall run?



Sorry for the easy question, but I searched & did not find the answer to this. the manual says 0 - VERY hot is OK, but what is normal for these motors w/o load & simply cruising @ 70 MPH?



how much would one expect the temp to go up with a 4000 Lb car & a 1500 Lb trailer?



thanks mucho

Bob

I have a '99 as well. When the truck is empty it's almost always right at 190 or a little less. When I'm towing ~6K and going up a long grade, pushing EGT's up to 1150 or so, the engine temp can reach 200-210 or so. As soon as I crest the hill and start down the other side the temp drops almost instantly. It's never heated up past the "safe" range on the stock gauge.

 

[Bobalos]

COOL, thanks mucho thats what I was kind of hoping for.



thanks again

Bob

 

[DavidC]

My 99 stat was 180 from the factory. The replacement is a 180 also.



Dave