Oil getting too hot

You put some sort of stop leak in the oil? If so hopefully all it’s stopped up is the oil cooler. I’d pull a sample and send it off and if you know what you’re looking for pull the valve covers.

 

I am thinking that the oil cooler is failing. I would suggest 1st to get a inferred heat gun and check the temp on the oil pan

 

Well, I’ll ask the obvious question is there any oil in the coolant?

 

I'm not a mechanic but my pete 389's oil pressure is at 39 or 40. Idk if that would have anything to do with it

 

I would think oil pressure would also drop, with it running hotter. If not, maybe it’s just the guage. Otherwise the oil cooler must be plugged up. I’ve used the Lucas stop leak, never plugged up the cooler. I’m guessing there’s a bypass valve, like a Detroit has. I would just change it, to rule it out.

 

The OP’s engine is an older CAT and runs higher oil pressure then your X15 cummins.

 

Have a sample of the used oil tested. While you wait for the results to come in replace the oil cooler. If the temps go down and the test results are clear problem solved.

If a new oil cooler has no effect and/or tests show high levels of bearing material / O-ring material mystery solved. You mentioned the truck leaked oil before. Did it ever leak very low before top ups? If it's internal, repair the excess friction parts and inspect + clean oil passages and hoses which led to the issue. It would be a good idea to fix the original oil leak at that time too.

Before diving into repairs Double check the oil pressure is normal with an external gauge and that the Radiator + cooling system is functioning properly.

Here's hoping it's the first scenario!

 

oil cooler has thermostat in it.laser temp gun on oil pan when hot best place to start.if oil cooler bad most times leak into radiator.