Help... no oil pressure on Cummins ISX 15

It won't be if it ran for even a few minutes with no oil pressure......

 

@pushbroom is saying you should drop a cap or two to make sure the bearings aren't damaged from oil starvation.

 

That doesnt necessarily mean a whole lot to me.

Oil pumps dont regularly fail to the point of no pressure. If it's being driven and has oil it's working. In order to create pressure you need containment. Your crank and cam bearings are the main source of that containment.

Drop the pan. Inspect the suction and pressure tubes for proper installation and obstructions. Drop #4 and #1 rods and mains while you in there. Pull the valve cover and have a look at the cam bearings too. Have you cut open old filters yet?

 

Time to drop the pan and hope for the best with all the bearings in the engine being ok.

 

Not to mention the top end too.

 

You drove it into shop, they changed oil filter and now no oil pressure?

If the last time you changed oil and filter the oil pressure jumped back up then I would say the inside of the engine is dirty and clogging the filter.

 

Kind of acts like it lost its prime, but you were already having oil pressure problems. I would be dropping that oil pan for a look. No oil flow at all would have me looking at oil pump and oil pickup tube.