serpentine belt tensioner 1998 sc2
 

When I removed the serpentine belt tensioner, i noted that one of the mounting bolts was loose. I found a hole on the bottom right side of the mounting circle. The hole is in the block at about 5 oclock, and is about 1/2 inch in diameter, filled with oil. Is this hole supposed to be there, or was it possibly caused by the loose tensioner?