I think I know what you're talking about with those holes in the front. I probed them with a small screw driver but it doesn't feel like it's open but I can't see in there so I don't know for sure. I know what these holes are. They're the mounting holes for the air pump assembly. Does that top hole have oil flowing throw it and around it? I believe that and the leaking intake manifold is where the oil is coming from.