Engine/Transmission (1994 - 1998) coolant temp. will not stablilize

[MGarland]

Did you just drill 1 hole? If so how big.

Thanks, MGarland

 

[WDixon27]

about 2mm and one on ether side, i wanted coolant to circulate past the element to help keep it from getting shocked and reacting too quickly, i think the thermostat is too far out of circulation the way the little bypass hose is routed. i could be wrong, it's happened before, it'll probably happen again

 

[Johnstra]

I went with the cardboard over the radiator and that worked well for me. I covered about 2/3 of my radiator (between the radiator and intercooler). Running @ 70 MPG on the highway, which averages about 600-650* EGTs on fairly level stretches my temp sat just shy of 190*. Climbing the mountain going home, which is about 20 minutes running @ 950* EGTs my coolant temp was about 2 needle widths above 190*. Coolant temp never did wander around.

-john

 

[biggy238]

Johnstra had about the same situation I did.

I didn't cover the whole radiator/intercooler and put the cardboard in between them. . I thought the result were uuhhh, very livable. (toasty)

 

[MGarland]

Just wanted to give everybody an update on this situation, I drilled 2 . 080 holes in the t-stat and it has cured the huge variation in water temp. It now stays about 170 deg. all the time when you are running empty and it will get up to 190 deg. when I am loaded, it takes a little longer to warm up in the morning but I guess that is the trade off. I want to thank all the guy's that responded to my post and gave me all the great advice.

Thanks MGarland

 

[DBraunig]

Normal for sure, but the new T-stat helps a lot. From Dave Fritz's page:



* Cummins Thermostat:



A series of revised part numbers has been issued - check with a Cummins parts department for the latest. P/N 3934373

eliminates temperature fluctuation but engine warmup is slower and the operating temperature is lower than with previous t-stats.





Dave