So my 3.0 merc I/O has a bad riser and manifold what I noticed before I discovered the leak on the riser was rust and a small amount of water under the lifter cover on the other side of the engine when I pulled the riser and manifold off and started cleaning up the rust that had formed below the riser onto the engine block was that the leak was traveling around the back of the block and winding up below the lifter cover. At least this is what I’m thinking if it was a head gasket wouldn’t there be more of a mess and water in the oil did anyone else ever experience this happen to them in any event I’m going to find out soon because I ordered a new manifold and riser
