Engine/Transmission (1994 - 1998) NAPA T-STAT I hate them....

[biggy238]

This is the second T-stat from them I have run that sticks shut on the first warm up run.







I also think this has gotten my head gasket this time.



This thing runs up to the zero on 190 before the stat kicks open. (whatever temp that correlates to)



Too bad my brother was driving and didn't notice it.





Viva la Cummins!!! (and their OEM parts)



If it weren't for the home-town relations I have with the store owners, i'd probably smear NAPA parts pretty hard here around home.

 

[GDMRTN]

I'll never use a aftermarket thermostat. Cummins has a updated one that is more stabil in temperature than others. Available at your friendly dealer for a smart penny.

 

[tp0d]

Try running the heater on the initial stat cycle... it returns hot water to the other side of the stat, causing it to heat up faster. seems to work for me... I dunno who's stat I have, but its always done the same as you describe. . owell

-j

 

[vssman]

I had a similar problem with a Stant T-stat. It would go to 220 before it opened then would cycle normally. After messing with it for a few days, I went back to a cummins stat which works like one would expect.

 

[Don Tanklage]

does the napa stat have the two small 'pins' (they function as check valves) in it?



i got my stat from cummins and it had the pins



i heard all the horror stories and cut those pins off before installing the stat



mine works perfectly



180°

 

[biggy238]

The heater didn't help like I thought it would.



For some reason, a short burst of RPM (kick it into neutral and goose it) Will kick it open. I guess the sudden change in water pressure shocks it?

 

[CumminsPower98]

The heater didn't help because it's flowing coolant all the time anyway. The only thing that changes the in cab temp is the blend door. Many vehicles have valves but these do not to my knowledge unless there is one hiding inside the cab, but I doubt that. I have had mine up to 230 towing a few times so I doubt you hurt the HG but if it did get hurt it was already really weak.

I agree. I use Cummins only and mine runs very steady with no holes drilled as some do. I have mechanical gauge so I can see what's really going on a lot faster than the stocker.