Engine in question, diatshu 3cly vanguard 31 hp turbo diesel. Problem is. Engine was running fine, only has about 400hrs on it. Mowed lawn, about 15 min total run time, shut engine off for about 5 min and when recranked it knocked. Loaded on trailer and took home. Set on trailer for a few days before trying to unload. When cranking the engine seemed to be low on compression, used small squirt of either and engine fired but didnot knock. White smoke came from exhaust. First thoughts blown head gasket but smoke seemed more unburnt diesel that water. Unloaded tractor and parked in garage. Total run time about 5 min. Shut engine down and it started to puke water. Temp guage said 180. Again thought blown head gasket or cracked head. Tractor sat in garage for a week and cranked to trouble shoot. Engine cranked fine still white smoke but no compression in radiator and smoke was very oily as in diesel fule, not motor oil. Almost as if tractor wasnt fireing and just pumping pure diesel mist out exhaust. Ran tractor for a few min and it never got hot or puked any water. Shut down engine and havent touched since. I am leaning toward blown head gasket or cracked head but this isnt making any since. Pukeing water but not hot and no compression in radiator, Low on power and spewing diesel out the exhaust. Knocks one time and not the next. seems low on compression and wont fire without either one min and then cranks fine the next time. All starts where cold starts after the tractor had sat unused for several days. Any opinons before I tear this engine down.