oil leak

scotsdale3 · Jul 17, 2005

I have a yanmar ym2000, and there is what looks like a small rubber drain hose coming from the side of the motor and running down. I notice that some oil was blowing out of this hose and sometimes smoke. Why is this happening?

Thanks

mark777 · Jul 17, 2005

Does it attach to your valve cover side or back? It is probably your crankcase ventilation tube exhausting under the tractor.

Venting positive pressure building in the bottom end of diesel engines (from pistons down) is necessary to keep block seals and gaskets from blowing out. Excessive smoke is an indication of blowby and may be from worn rings or cylinder walls.

Welcome to TBN.

Regards, Mark

normde2001 · Jul 18, 2005

Is your oil overfull, possibly fuel in crankcase, and is your oil dipstick sealing properly? I don't know if that is a PCV, (one way), type vent, if so you might check to see if it is gummed up. I also have a YM2000, but have never looked at the vent.

mark777 · Jul 18, 2005

Your right about that...it really is a breather simply vented down below the engine. Not sure on the YM2000, but the ones I have cleaned/maintenance'd simply consist of a folded fine stainless steel wire mesh and vented spacer...looks very much like a thermostat housing.

This one is a 3T75U and is located on top of the valve cover.