my truck is starting to run a little hot going up hills and on hot days.the temp goes over 190 consistantly and then settles back down below.it has 195k on it and i think it is the orig thermostat.i plan on changing the thermostat soon here.should i go with a 190 or 180 degree.should i get it through the dealer or napa.coolant is good.i changed it a few months ago.thanks

 

Your radiator could be plugged up from the crankcase vent bottle (puke bottle) Its amazing just how much crud can accumulate.

 

Radiator is probably getting plugged with dirt and oil from the blow-by bottle.Go with a 190* and Napa coolant will work, just add some RP additive.

 

you shouldn't lose more than a few ounces of water changing the thermo. I have done it without draining the rad and barely spilled aything

 

100,000 miles and over 30% blockage. The radiator looked fine untill I got it out. This is the radiator side that faces the A/C condenser.

https://www.dieseltruckresource.com/...1&d=1217283623

 

Doesn't sound like a bad thermo if you're temps aren't fluctuating or your not warming up. The 24v like a 190. If you are gonna flush and fill get the rear end up as high as you can to drain the block better. Run a straight premix coolant, you don't want a lot of water in your system. I ran the Delo premix. Cleaning the radiator exterior is probably your real problem, though.

Kurt

 

Depending on your location (richf's is not given).......I disagree.
My 02 loves the Cummins 180* T-Stat, especially in the summer. Takes a bit longer to warm up in winter but no biggy. Flows much better. At track, my old 190* would quickly cook up to 220-230*. The 180* never gets higher that 190*.

The Dodge 190* T-stat has a plate on it to improve warm up but I'm convinced it reduces flow somehow.

Cummins T-Stats have no such plate. If interested...The 180* Cummins is PN# 3967195.

Your Radiator/CAC/Condenser may also need cleaning. Do a search on back flushing tool. Lots of info. Can start HERE.


RJ

 

I had a dirty radiator thanks to the vapors from the puke bottle. First thing I did was to add the hose to the puke bottle[now its behind the tranny cross brace on the frame]. then I cleaned the dirty dust and debris from the radiator core, then a new T-stat. My stock thermostat was 190 degree, but when I went to the Cummins shop they asked for the motor # and said it called for 180 degree, and so that is what I bought. now i can't get it to go over 180 ,even towing uphill with the temps outside in the high 90's.

 

After researching this site before doing my flush and fill I noticed the 190 seemed to be the temp of choice for the 01, suggested by members and Cummins, so that's what I went with and I haven't had any hot temps that I've noticed, but I am in the Pacific Northwest which is a tad cooler than Texas!

Many responded that diesels like to run hot, but 190 isn't really hot compared to gassers that run 200 or more with emissions. I tend to go with what suggested by the manufacturer, in this case Cummins, when I chose to stick with the stock thermostat.

A lower stat may be good medicine in the hotter regions, hence I agree with RowJ re: the 180 if you get higher than average summer temps.

Kurt

 

thanks.i am used to marine diesels that run 165-170 at 1500 for hours-days on end.