60 series oil temp average?

Hello,
I have a 1994 international 9400 with a detroit 60 series ddec II engine. It is a 9 speed with 3.74 rear ends.
Since I have owned the truck (4 years) the engine oil temp gauge never worked. I finally replaced it and when I made a trip the reading stayed around 270 degrees. It would slightly go down here and there to maybe 230 and then come back up to 270. The road was rolling hills but over the 2 days it didn't seem to make a difference being on flatter land. I was hauling doubles, a combine with a grain trailer behind it so it is a good load but it was only 60-65 degrees out and partly cloudy. I have pulled the radiator resealed the tanks had it cleaned, new coolant, filter, sensor, and thermostats before this so my temp gauge was at 190 basically all day. oil pressure at 14-1500 rpms was around 52-54 that seems normal to me?
I am wondering since I don't have a baseline in this truck or engine what my temp should be. if this is normal or not. Then if it's not ideas? obviously oil cooler in the front, but what about the one inside? I would be interested in what heavy haulers temp would be at, my load isn't the heaviest but its like a giant sail. I wont be around it for a couple weeks so can't drive it empty to see how it acts then.

Thanks for any help I appreciate it

 

ok that does make sense my partner pulling the same load but has another 100 horse, was like you say 20 over his coolant. 9 speed and lower horse for me I have to shift a lot compared to him but that shouldn't get it +80 degrees over coolant? I got both sensors straight from international so I do trust them in a way.
thanks

 

I changed the sensor that is screwed into the bottom of the oil pan. Before I did that I tested the wire down there by grounding it and it moved my gauge. im assuming change front oil cooler with the fins but i didnt know there was one inside the oil cooler housing as well

 

Ok i was wondering what temp would get check engine but it never came up. I don't have a trans temp gauge either, I guess i didn't think of it being a trans cooler. I have all the tools to do physical work but I do not have the computer or ecm stuff. I'm assuming I would have to get it up to temperature and then plug in to see what it's reading vs the gauge or does it keep a history? I don't know much about that side of things. when the sensor didn't work I never got a check engine or anything like that maybe they are separate? I'm thinking the sensor down there just runs directly to the gauge maybe and not giving me the correct reading idk.

 

I dont want to throw parts at it if Its not actually a problem if its just the gauge and sensor I need to use the truck for about 5 weeks then will have free time to dig into it but obviously if its a problem like the oil cooler I would want to fix it before I start here in a week or to. I read that oil pressure should go up as well if the oil cooler is getting plugged or not working? I feel like my pressure was good at 52 or so at 1500 rpm but then again I don't exactly know what normal is either haha.

 

Ok I will work on that, thank you. Do you know the signs of a bad oil cooler?