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smoking Kubota diesel question

Stevenbrla ยท 2011-09-11 20:31

I have a Donkey forklift with a little Kubota diesel. The new models use D1105, not sure what mine is (I'm at home right now, and forklift isn't.) About 2 weeks ago I noticed that it seemed to be smoking... not white smoke, just normal diesel exhaust, but more than normal, while operating. The smoke is coming from a tube next to the exhaust pipe... the tube comes from the top of the engine. The engine is about 13 years old, hour meter shows 1300 hours, but have no idea if that is accurate. Any idea what this is, what might be the problem? I can get model numbers and pics if that helps. Thanks!!

Replies4
  1. #1willie592011-09-11 21:41

    Would that be the crankcase ventilation tube coming from top of valve cover?

  2. #2Stevenbrla2011-09-11 21:58

    That sounds right to me, Willie. So what's that mean... why's it smoking more all of a sudden?

  3. #3willie592011-09-11 22:40

    All of a sudden, good question. Excessive crankcase pressure, smoke from vent tube, typically is caused by combustion pressure leakage at piston rings. It can also happen if there is excessive wear of exhaust valve guides, but that rarely is a "sudden" thing. Sudden would be more related to a failure of compression ring of at least one piston, only a compression test of warmed up engine would verify this. But consider the engine is 13 yrs old. If it starts good cold, doesn't have a noticeable miss to it, doesn't consume an excessive amount of engine oil, I wouldn't put a lot of worry in it. An aged engine is going to produce smoke from crankcase vent tube.

  4. #4Stevenbrla2011-09-12 06:40

    It starts pretty well, and not using excessive oil.... I'll put my worries elsewhere for now... Thanks Willie!