Loud howling noise has Cummins Techs stumped.

Yeah prob the cap on the expansion tank bleeding off pressure from bad head gasket,dropped liner ect....

Basically pressure in the cooling system

Run with the cap loose and see if it goes away.

 

Before I read this, I was going to say it sounded like the fuel pump... my truck made the same type of noise you explained. I had my fuel pump replaced,, $5400.
I walk past trucks now, and hear that noise, and I'm like, oh no! Fuel pump needed soon! Good thing they took care of you. I bet if you heard that sound from another truck, you'll know what it is!

 

Some of those pumps had press on gears that would spin free on shaft after some use, ck. if shop used a rebuilt or new oil pump, hope its a easy fix like a broken wire!

 

I've cross my fingers I'm wrong
Your old pump was with ceramic plungers( by the truck age) If plungers were cracked and mechanic didn't check it (i'm sure he didn't) abrasive ceramic particles in oil system will kill engine in about what you said distance.
Hopefully I'm wrong.

 

Did they fix the ceramic fuel pump with newer isx? What was last year if they corrected it?

 

They have it fixed form 2014 I believe. Before 2014 they were playing forth and back with changing parts and design. I'm surprised with such a low price for pump replacement. As I know from people across all states the price is $ 4000 - 3500 just for the pump. Plus labor it going to 4800 - 4000.
But who knows probably we still have some good people here.

 

Oh noooooo.
Really sad. I was in your shoes exactly year ago in Houston. Shop denied to pay any money to help replace engine after their overhaul and engine was completely destroyed by monkey with wrenches.