I have a crawler-loader that has a 4 cyl diesel in it... I broke the crank in it right under the #2 main bearing.. I did it twice the same way.. it would just loose power and a minor knocking... the main thing it was a MAJOR PITA to get it fired up.. basically it turned into a 2 cyl engine... I found out later that the previous owner blew the head off the engine using starting fluid.. I believe he cracked the crank and bent the block