while tring to tune my fuel pressure, pretty sure cracked a piston

[78f100]

I thought the same thing with mine....Excessive CCV pressure....enough white smoke to where sitting still in traffic it looked like a fire and there was a knock too.

I had a leak in the fuel rails at the end cap....it was dumping fuel in the crankcase almost 4 gallons worth! Which caused excess pressure and thinned the oil enough to where there was excessive noise.....IF it happened while you were tuning the air dog it might be the problem. Fuel pressure caused a leak that normally wasnt there.....

Easiest check.....take some old oil jugs and change the oil....ONE if it smells like fuel TWO if you have more oil than supposed too you could have the same thing.

You ended up being right, I did have a bad injector but also when I changed the oil after replacing the injector I had about 1.5 gal of fuel in the oil. This was the first oilchange since the build, I thought the fuel came from when the injector went out. When I replaced the injector I pulled all 4 on the dr side, I was not sure if the injector would fix the knock so I didnt replace the fuel tubes, orings or change the oil, It ran good so I changed the oil drove it about 200 miles noticed fuel smell in the oil dropped it sure enough more fuel. Then I replaced the tubes thinking since I reused them they might be leaking,o rings, and oil, drove the truck for 250 miles checked the oil overfilled again, dropped oil had 1/2 gal of fuel in it. I went to ford and got new rails 300 each and they gave me a break on them, I am not happy that I sent my good rails in as cores and got these leaking son of a guns, but lesson learned. I had read about others having the same issue with this shops rails, (they were NOT from Elite) I even checked the end caps, just by holding them in my hand and making sure they were tight, guess I should have put them in a vice and torqued the crap out of them, then again I shouldn't have had to worry with it. Just another expensive lesson.