New Thermostat Impressions

[Greenleaf]

Installed new NAPA thermostat. Standard-Thomson brand (made in USA). It swings and hunts like the Cummins unit, however, at a constant load/throttle setting, it finds a happy medium and settles down. The Cummins stat never stopped moving except when I pulled a 5k load in FL during the month of August.



You must specify the thermo seal as you will NOT recieve said seal with the thermo, unlike the Cummins "kit"

 

[bgilbert]

You must specify the thermo seal as you will NOT recieve said seal with the thermo, unlike the Cummins "kit"

Yep I noticed this when searching on most of the parts stores websites, gotta get 'two' items. For my crew I'm gonna reuse an old Cummins stat that I pulled from my 91. 5. It was like new when removed, but the new C stat didn't solve my low heat issue last winter, both worked the same.

 

[Don Tanklage]

are you guys running the stock gauge or a aftermarket gauge?



i bought my stat from cummins (180° stock replacement) and my gauge is a SW mech



stat opens at exactly 180° and keeps my truck right there when cruising



the stock gauge is still hooked up too, and it is not rock steady like the SW, but more like all over the place!



don

 

[Greenleaf]

It's the thermo in my case. I changed the thermo a few years back and since then, the OEM gauge sweeps side to side. You likely did not install the SW unit at the factory location either. The reading will be different. Not good or bad. Just different.