As mentioned above, it's part of the PCV system.
There's a little chamber with a baffle built into the large aluminum alternator bracket. Any positive crankcase pressure is routed down into this box and then out the vent tube in the bottom of the bracket (vents right next to the crank pulley, on the passenger side). There's a drain line for any liquids to drain back to the oil pan (that's the hose in your picture). There's 6 screws holding a cover on the front side of the bracket, which is where you'd access the chamber.
There's a check valve screwed into the bracket, that goes to that hose. Make sure it's not plugged. I could easily blow through mine.
Mine looked similarly messy to yours, though maybe not quite that bad. For reasons that I could not figure out, there's a ~3/8" diameter hole in the back side of the bracket, routing into the PCV chamber. This makes no sense to me, considering that there's already the vent out of the bottom. This hole was clearly the source of the oily mess on my motor. My truck has excellent compression across all 8 cylinders and no detectible blow-by, so I just chalked it up to 260k miles of neglect.
I plugged the hole, and for ~2k miles now, all is well. If you do plug it, watch for the clearance on the back side. It's a fairly tight fit between the bracket and block.
There's a little chamber with a baffle built into the large aluminum alternator bracket. Any positive crankcase pressure is routed down into this box and then out the vent tube in the bottom of the bracket (vents right next to the crank pulley, on the passenger side). There's a drain line for any liquids to drain back to the oil pan (that's the hose in your picture). There's 6 screws holding a cover on the front side of the bracket, which is where you'd access the chamber.
There's a check valve screwed into the bracket, that goes to that hose. Make sure it's not plugged. I could easily blow through mine.
Mine looked similarly messy to yours, though maybe not quite that bad. For reasons that I could not figure out, there's a ~3/8" diameter hole in the back side of the bracket, routing into the PCV chamber. This makes no sense to me, considering that there's already the vent out of the bottom. This hole was clearly the source of the oily mess on my motor. My truck has excellent compression across all 8 cylinders and no detectible blow-by, so I just chalked it up to 260k miles of neglect.
I plugged the hole, and for ~2k miles now, all is well. If you do plug it, watch for the clearance on the back side. It's a fairly tight fit between the bracket and block.
