Junk cummins thermostat!!!

[2broke2smoke]

check your thermostats ...



1 minute job ...



been smelling antifreeze so i figured might as well do the 'stat and pump as long as i'm doin' the heater core ...



as posted by someone else recently the stock stat is pure crap ...



mine has lost 80% of the rubberized coating on the internal part of the 'stat



not the o-ring but the part that actually moves up and down ...



got a chunk of rubber the size of a quarter somewhere in my system now ...



3 8mm bolts ... torque specs @ 18 ft/lbs per manual ... napa part is MUCH higher quality part # 375-190



5 minutes may save you big ...

 

[EricBu12]

Was your t-stat the original one? or the black one from Cummins? I have the black one from cummins for my 2nd gen. is that the one you are talking about?

 

[Tractorat]

Im just under 60k on my 02. Its been running hot when towing up a steep grade, and hotter than it used to up just an average grade (towing). All of the posts said to clean the radiator (grime from the crank case bottle). Although it looked pretty clean, I washed it as best I could without removing the radiator. Helped a little, but not much. The posts said to remove the radiator so it could get a really good cleaning. I wasnt looking forward to that job. So, as a last resort, I changed the tstat (well, I had a shop do it). Problem went away. I didnt see the old tstat, and didnt ask. But Im guessing that it had been in bad shape for a long time. I wish I had changed it out a couple of years ago. Yes, at least in my opinion, the stock tstat is junk.



TRat

 

[DBentley]

2 broke was that bad tstat on the 06 or the 01 ?

 

[WDaniels]

256K on my original tstat and nary a trouble.

WD

 

[2broke2smoke]

it was on the '01 ...



it was the original ...



and i wasn't having any troubles with it, just starting smelling antifreeze in the cab so bought the thermostat and water pump as long as i was changing the heater core and flushing the system



there was a recent post on here about how the napa part was much higher quality and the cummins part had lost the little brass O on the bottom, and in the napa 'stat it was encased in the 'stat housing so you couldn't loose it ...



on mine the rubber coating on the internals of the stat had came off ...



truck heats up in half the time now because the stat would not seal off at all

 

[2broke2smoke]

here is the previous post i referred to above ...



good photos



https://www.turbodieselregister.com...180302-defective-t-stat-thought-id-share.html

 

[OL RATLR]

here is the previous post i referred to above ...



good photos



https://www.turbodieselregister.com...180302-defective-t-stat-thought-id-share.html

Well I got 111000 out of my thermostat just replaced it.



Nothing last for ever does it. :-{}

 

[bgilbert]

Good luck with your NAPA stat. It's been covered here for years that NAPA stats are known junk. What was the part number of your old stat and how many miles on it? I like NAPA stats and parts in my gassers, but NAPA stats and fan clutches aren't going near my CTD.

 

[HEMI®Dart]

Good luck with your NAPA stat. It's been covered here for years that NAPA stats are known junk.

Some guys have had good luck w/ the NAPA T-Stats , others no. The Cummins one looks like a higher quality design. It has the rubber ring around it.



I dunno.

 

[Joe G.]

I have a NAPA T-stat that I got when I was on a fishing trip in Oregon. I expected to have to replace it before too long, but it has been working fine for a few years now.

 

[CStraface]

So the T-Stat problems are only on 2nd gen trucks? Because I sware that my water pump turns on more often then it did before, and it sure seems like my operating temp goes above 200* more then it ever did before. Mind you, it only goes above for a second or two, but still...

 

[EricBu12]

2 broke,



the cummins thermostat I replaced recently is sorta like the napa one you bought. My origional t-stat was broken at the top bridge... the new one I have is sorta a compasite body and the valve is inside... so 6 years ago, you know parts change all the time... look at our lift pumps. . new numbers and redoos and such...