2014 MP8/D13 Oil temp help

Oil should be right around the same temp as coolant. I believe there's a solenoid valve that controls the flow of oil to the cooler, if that's having an issue it could cause higher than normal oil temps. But it should log a fault, unless its mechanically broken.

 

Those oil temps sound about like what I have seen. Mack runs their oil hot for some reason.

 

When you say guess down to 220 to 230 at idle how long is it at idle to drop to that temperature?

Have a 2018 that will drop to 200 at idle after say 10 minutes of idle.

Mine usually runs at 230 going down the road.

 

When my truck is hot and at idle oil pressure will be about 25psi once the oil cools the oil pressure will jump at least 10psi. It's like the solenoid thing closes the flow of oil thru the cooler and causes the oil pressure to rise quickly.

 

That’s why I run mine on synthetic oil, even though they say it doesn’t need it.

 

Mine when hot and let’s say I come to a light it drops to 19 or 20 psi but when I leave it idling for a couple of minutes it goes to like 22-23 psi hot . Going 65 or 70 mph it’s at 47- 49 psi is that normal have been seeing that oil pressure suddenly goes to like 44 psi at idle when hot and idling for a couple of minutes then goes down again . Don’t know what’s going on .