I found my oil level to be very high which was, I think, causing the pressure to fluctuate. I'd guess there were at least 4 quarts too much. I believe it's fuel in the oil. Where can it be coming from? Lift pump, injector pump, injectors??? The truck runs great and isn't showing any white smoke leading me to think the LP is leaking fuel. Thoughts?

 

Lift pump would be my first guess. I am pretty sure the P7100 cant leak fuel into the crankcase ( at least I have never heard of one doing it ), and I would say you should hear and feel an Injector leaking that much.

 

That's what I'm thinking. I can't imagine injectors leaking or the lift pump and not having it run rough or see white smoke...

 

Fuel supply pressure in excess of 45 psi can blow through internal injection pump seals and end up in the oil.
Did you happen to stretch the overflow valve spring?

http://www.cumminsforum.com/forum/94...-12-valve.html

 

No, it was replaced a good 10+ years ago but not stretched.

 

Leaking through the lift pump... Tipped the pump and fuel poured out the plunger. Who carries the metal line between the lift pump and filter housing?

 

Dodge and Cummins