from what i see in the picture looks to be a crack in the case, is this right? you can fix this by stop drilling each end of the crack with a 1/8 drill bit, just be careful when drilling making sure you drill only thru the case and you're be alright, then take a rotary file in a drill motor and remove a little material from the crack making a v shape, clean the area with some degreaser to remove any oil residue, fill in the crack with JB WELD , this will permanently fix the crack.
if you choose not to stop drill the ends of the crack it will contuine to crack . stop drilling is important to permanently fix this area, the other alternative is to remove engine and replace the left hand side case.