Air Connection(s) on Crank Case Vent Tube?

[todds112]

So I added a longer slobber tube today. I got the NAPA one 3' 1.25" I.D. I noticed on the metal part of the tube that curves down and out around the turbo, there is an air line plumbed in. Right above it there is another threaded hole with nothing in it. I was trying to trace the airline, but a big storm hit, so I quit for the day (no pics yet, either).

I've found some diagrams of it in the TM's but none of them say what it's for. Some of the diagrams show another line in the empty hole that I have. I'm wondering if I should just plug the open hole. Still trying to run down some oil leaks in the area. The fitting on the oil line to the turbo is leaking at the engine block. It was loose and I tightened it a bit, but it's still leaking.

 

[Jeepsinker]

That oil line may be cracked if it is still leaking. The line that used to go in the empty hole is the fuel tank vent line. On some trucks they were removed from there and had an axle vent screwed onto the line, leaving that open hole on the slobber tube. I have trucks done both ways here.

 

[todds112]

I see, thanks! Wouldn't hurt anything to block it off (the open hole) then?

I'll pull the oil line out and check it for cracks.

 

[Jeepsinker]

Yes you can plug it. I'm going to plumb mine back into the fuel tank vent. Just makes sense as Iv'e already had the axle vent on the vent line fail and pull a massive vacuum on the fuel tank, to the point that it was choking my engine down and I had to stop and disconnect the vent line from the tank. No reason to put a part with a high failure rate in a place where it need not be and will ( and has ) only caused a problem.
If that oil line is cracked, it is probably a hairline crack and you may not see it. There is also a gasket between the fitting boss on the block that may be leaking. You should clean it well with brake cleaner and then run it at idle and watch carefully for the source.