Cummins ISX 485ST low oil pressure

So I just bought a kenworth with a ISX 485ST Cummins and I'm getting low oil pressure at a constant 20psi city streets and highway speeds. And whenever it it goes a little bit below the 20psi mark the engine goes crazy, the check engine light turns on and then the stop engine light turns on and after a half of min or so the truck turns off while running. So would it be the oil pump or the oil regulator for the loss of pressure? Or even the filters? I don't know when it was last serviced since I just got it about two days ago. Any help please?!?! Thank you!

 

I think I will do that as soon as possible, I've been reading similar threads like mine and many have suggested to replace filters and oil. If that fails I guess I'll be taking back to kenworth, I'm glad I grabbed that warranty before taking off the lot or else I would be worried as heck.

 

True that!.......temps are normal on the oil and cooler. I had a problem similar to this on my other truck once, it's a cat 3406e on a old Pete. The oil pressure was at 40 and that had me worried because it would always run 50psi or higher, then I got it serviced at came back to normal. Then I decided to try out the Cummins and now I get this, I was like nope, 20psi on the oil ot normal at all. I called my sales man at kenworth and told him about the issue and said he was going to ask the shop tech at kenworth, we'll see what he says! Lol

 

Lol so yes, I got it serviced and after that until now the oil pressure has gone back to normal. It's running at 40 psi now, which I think it's normal. That's the news for now!