I have had 2 trucks that were ran with def in it that caused the high pressure fuel pump to lock up. Once the high pressure fuel pump locked up it caused the crank gear to spin. When I pulled the front cover it was obvious what happened. The 2 trucks I had do that also had fuel pouring out of the high pressure fuel pump and into the engine valley when the fuel pump was turned on. I don't know if the helps but it might be something to look at.
low compression after run on def
in 6.7L Power Stroke® Diesel Engines
Posted
I have had 2 trucks that were ran with def in it that caused the high pressure fuel pump to lock up. Once the high pressure fuel pump locked up it caused the crank gear to spin. When I pulled the front cover it was obvious what happened. The 2 trucks I had do that also had fuel pouring out of the high pressure fuel pump and into the engine valley when the fuel pump was turned on. I don't know if the helps but it might be something to look at.