I was wondering if any of you has had a sweeping water temp , and how you fixed it. I have replaced the thermostat and the sensor. I have heard that a heater line runs into the t-stat housing and will cause it to open and close. To fix this they drilled a 2mm hole in the t-stat.

Any thoughts

Thanks

 

I think that is normal mine sweeps from 140-190 all the time. Big radiator, stat opens down goes the temp. I had a 350 ford with a 460 that done that. I drilled a few holes around the stat ring and stopped it. But now I am older and a little wiser and I belive its supposed to do that. The cummins will steady out when pulling a load.

 

I dont see how that much change could be normal or good for the motor, but I could be wrong, and i dont pull

 

Ahh 50* swing I dont think is bad. OK guys what do you all think?