Originally Posted by joeyhodges
I have a 2004 Journey diesel. There is a small pipe just right of center that fumes come out of only when the engine is running. I can't find it in any manuals or drawings. It is not the large 6 or 7 inch exhaust pipe. Anyone know what it is?
Here is a link to a photo:
As has been stated, it's your "blow-by" tube. You see, without going into the whole high school auto shop lesson on how an engine operates, suffice to say that, when your engine is running, not all the compression from the pistons doing their job of compressing air is used. Some of it get's by the piston rings and, ends up as pressure inside the crank case. Well, that pressure has to be dealt with. For yours and, a few zillion other diesels out there in this era, all the manufacturers did was, simply install a vent tube on the engine, to release all that "crank case pressure".
And, it is expelled, out of that tube. But, CAT, in the mfg of the engine, only put the exhaust part of that tube, right below the middle of the engine. Well, that caused some serious problems due to the oil vapors that were expelled with it.
So, those tubes, should be, and it appears yours was, extended to the rear of the coach so that when they vent, they cause no issues with other parts of the coach. You more than likely have a CAT 300, or 330HP engine. Both of which require a maximum of 19 quarts of oil for an oil change, including with a filter.
If there's more than 19 quarts in it, that extra amount of oil get's splashed around and, ends up entering that exhaust port of that vent tube. When that happens, it gets spewed out and, quite possibly all over the toad your towing behind your coach.
So, the point, make sure you're carrying the proper amount of oil and, your dip stick is marked and or adjusted correctly for that proper amount. Other than that, that little tube sticking out is where it's supposed to be. Good luck.