Yanmar 2GM20F oil consumption

[Ralph Johnstone]

Gordon,What would you expect the oil consumption to be on the above engine with 300 hrs on it. It is driving a Hunter 310 usually at approx. 5.5 knots and 2600 RPM ? I have been changing the oil every 100 hours and notice I am down about 1/2" on the dip stick after the 100 hrs.One further question for the same engine ........ when pushing the engine to 3000 RPM I get a smell of oil and something similar to hot metal coming from the exhaust. There is no sign of smoke ............. only this smell. As mentioned before, the usual running speed is 2600 RPM.Thanks,s/v Island Hunter

 

[Rick]

Similar problem

This is similar to experience with my 4jh3e (see post). Also notice problem at high RPM and notice smell of oil when accelerating. Also don't see any smoke. Oil level has dropped below fill line after 100 hrs. Can't help but I'm curious about the answer. I've never had a diesel that ate oil like this and I don't think it's normal.

 

[Gordon Torresen]

Lube oil consumption

A properly running engine will consume some oil. Each time a piston makes a stroke, some of the oil that lubricates the cylinder wall is left behind to be burned. I wouldn't be too concerned with a half inch in 100 hours.This may lessen as you get more hours on the engine. Stay observant. Explaining the smell will require a little speculation. A lot of hot gas starts to cool at the mixing elbow at 2600 RPM. Some of the oil that is being burned is sticking to the hose on the down side of the elbow. When the speed is increased to 3000, even more hot gas must be cooled by virtually the same amount of water. Ergo, the hoses get hotter and some of the oil already in the hose gets hot and makes a smell. As long as the gauges say you are not overheating, run it. The up side is that you have a half inch less oil to pump at change time.  An interesting observation of the two posts, both for 310's, is that one has 18 HP and the other 38. I know where to put my money on a drag race.