im thinking about ordering a guage for oil temp. 1. where do i hook it up and 2. what is the operating range of the cummins?

 

Just my though on it...

I would install the temp probe in the pan. Weld in a bung to the oil pan. Kinda of like doing a auto trans setup.

As for temps it should follow closely to coolant temps... It will be hotter but not much I think.

My 5 cents towards your project...

 

There is an extra fitting right next to the turbo oil line...on top of the oil filter housing. See my gallery-Pic of "HX-55, Installed". Can't see fitting, but the covered wire attached to the turbo oil line leads to it.

I always wanted an Oil temp gauge....finally got one....and it's boring!!
Mine reads 190* all the time at 70 mph...with one exception. Over 80 mph or OAT over 95*, it will go up to 200*.

Over 80 mph AND over 95* outside...will creap up to 210*

The most amazing thing to me is...in the hot summer months...and parked in my garage.... how long it takes to cool down. On a 90* day I have seen it still read 120* after 8 hrs of shutdown.

These readings are with 15-40, high quality Synthetic Oil.....and in the south.

RJ