Isx oil temp

[Isv1]

I know this is probably a topic discussed before but I have a 2015 Peterbilt 579 with an ISX in it original motor was warranted out because of a failure before I got the truck. When I acquired the truck it had about 280,000 Mi on it, and had previously been demandated. I knew the truck beforehand and when it wasn't de mandated, I know it isn't the cause of the issue I'm having, but my oil temperature runs normally around 225 on flat ground in this truck on Heels it gets up to 235 but not over over 240 it doesn't ever send any codes off. I verified the temperatures with my own temperature gauge through insight and some other things well.

I changed the oil cooler thinking it might have had an issue, it was a crate motor brought from Cummins and then installed in the truck. The issue started almost immediately, once previous owner got the truck back.

It ran normal for about a month then started slowly climbing and running hotter in normal operations on just the oil. That's why when I acquired the truck. I changed the oil cooler and the oil thermostat and I'm trying to figure out if it's just a Cummins thing why it's running hotter, or if I need to look at a deeper issue.