My motor home has a 2006 build Cummins ISL 400 HP with 94,000 miles. I last checked the oil level last month (2000 miles ago) and it was at the full mark. I changed the oil back in April.
I just noticed the oil level is about 2 qts low and oil has soaked the starter and the passenger side of the oil pan. Oil continues along the outside of the engine on the passenger side with some oil on the outside of the exhaust pipe.

I've developed a major oil leak some time within the last 2000 miles. It does not leak while sitting just when running. It has never leaked oil before.

Any suggestions?

I'm going to pressure wash the bottom of the engine and see if I can tell where the oil is leaking from.