I have a overheating problem when pulling my fiver thru the mountains. I have gone thru and replaced the radiator, water pump, all hoses, thromostate, and the fan seems to be fine Now the thermostate is a napa. Is there a lot of difference between napa and a commins thermostate? Also is there a spell check that can be accessed?

Charliex25

 

The Cummins T-stat has a "stop" on it that the NAPA doesn't have. It allows the T-Stat to "partialy" open, then open completely once at operating temps. The stop also keeps the T-Stat open enough to keep the engine in its designed operating range once warm.
I just talked to Cummins this morning( buying the update T-stat kit # 3802968 today) and received that explanation.

But from what the guy said, I cant think of what the difference would be between a 180* NAPA T-stat and the Cummins one once the truck was at operating temp... except that the Cummins one would not completely close as the temps cycled, guess that would keep the block cooler...

BTW the "kit" ( new T-stat and gaskets) lists at $31.43.
You might also read these two threads, the are recent and about this subject.
https://www.dieseltruckresource.com/...d.php?t=144311
https://www.dieseltruckresource.com/...d.php?t=144979

and do a google search for ieSpell, its an online spell check program