Engine Burning Oil

[Phil DiDomenico]

Looking for any advice on the likely cause or how I should proceed to determine the cause! I'm working with a Yanmar 2GM 18HP about 5 years old. I was motoring at about 22000 RPM when I felt a sudden vibration and the engine began to smoke. Any thoughts on a likely root cause would be appreciated.Thanks!

 

[Bob La Salle]

What color is/was the smoke?

The general rule is:white: water vapor (water in fuel)blue: oilblack: carbon build-upDid it pass through and return to normal? If so, you might have just passed some bad fuel. Then I would consider treating with biocide and conditioner, fill up fuel tank with fresh fuel, check/replace fuel filters, looking for water in the bottom of the filter canister or fuel separator if you have one. A small amount of air in the fuel line can also cause bad vibration without stopping the engine altogether. Diesel engines are very sensitive to impurities in the fuel. There is also a lot of stuff in the archives about different kinds of smoke being produced. Black smoke could be carbon build-up which you might be able to blow out by running the engine hard for 15-30 minutes. Blue smoke could mean that oil is getting into the combustion chamber. I would call a mechanic if that's the case. Tell us more.

 

[Bill O'Donovan]

Mixing elbow

After five years, the mixing elbow may have coked up shut. It has to be replaced if that's the case. The only way to know for sure is to remove it, no easy task. The Archives has much on this. Try other troubleshooting first. Ask around your dock as well.

 

[Phil DiDomenico]

Smoke is white

and farely extensive. No problems starting up, seems to run smooth however there was a definite change in the sound of the engine when it happened.

 

[Paul Akers]

White Smoke = air bubble

An infrequent puff (or cloud) of white smoke with shuttering that just "happens" could simply be a bit of air in your fuel system. Bleed the system again at the fuel pump, compression pump, and then at each of the two injectors , in that order. That may be your problem.I saw that happen to a marina mate. About two weeks later it happened to me and I did the above.That once happened to me and an authority who used to be affiliated with this site concurred with me.