Sounds like a injector tip cracked overfilling a cylinder and hydro locking the engine. Pull the glowplugs one by one and try to rotate the engine. When it does rotate you will have found the bad injector. Disable the fuel pump before you do this by unplugging the fuel pump to prevent continued fuel entering the engine.Got a 2007 6.0 F20..was driving down the road and the boots gauge maxed out and truck died....now it wont even turn over...there was oil that came down from passenger side. Was wondering what it could possibly be?