Yanmar 3YM 30hp problems?

[Mings74]

Hi,

Wonder what people’s thoughts are on this?.

Yanmar 3YM 30hp, normally very reliable, difficult to start and when it did clouds of white smoke that wouldn’t clear and sounded like a bag of spanners.
It would only run briefly.

Checked the oil dipstick showing double the amount of engine oil that it had?. Wondered if either water or fuel had found its way into the sump?, and if so why.

Thinking I need to check if the oil on the dipstick smells of diesel and check to see if I have any coolant (if it’s all in the sump). Any other suggestions or advice gratefully received. Cheers

 

[PabloPicasso]

Sounds like you're on the right track. Something is raising the oil level.

Is the oil breather blocked?
Is the deisel return or tank breather blocked?

If there's mehanical clatter it may indicate a more serious issue.

 

[Rappey]

Sounds like you already have an understanding of what the problems are and how to go about fault finding.
I wouldnt be starting the engine as if its diesel in the sump you could end up with a runaway diesel.

 

[Mings74]

Update…. Coolant level is fine, sump oil has funny smell….. diesel?. My new theory is leaky injector, not sure that would give white smoke though. Either way gotta find somebody to fix it!. Cheers

 

[vyv_cox]

Update…. Coolant level is fine, sump oil has funny smell….. diesel?. My new theory is leaky injector, not sure that would give white smoke though. Either way gotta find somebody to fix it!. Cheers

Look at the diaphragm in the lift pump. A split allows diesel into the sump.