Yanmar 4JH3-TE oil blow by turbo

[Alita49DS]

My Jeanneau has a 4JH3-TE which is turbo charged. There is a small amount of oil left in the tray under the engine after a number of hours of use. "Small" is hard to define as oil is a bit like blood. A little looks like a disaster. So probably less than half a cup.

The engineer who looks after the engine says that it is coming from the turbo and out of the air filter. There is indeed oil on that. And which would be consistent with there being oil on the gearbox casing at the rear of the engine. More to the point, he says that they all do it.

Is that right? Observations would be welcome.

I should say that I am not over concerned as the amount of oil to top up after several days of running (the Med really does either do dead calm or gale) is invariably from half way up the min/max on the dipstick to the max. It is just a pain having to swab the tray under the engine as it is so hard to get to. Even with the companionway steps removed.

Not as big a pain as changing in the impeller. Which the sadists at Yanmar, who put it backwards facing, combined with the sadists at Jeanneau who left minimal access.

[a64pilot]

If it’s not blow by from the engine, if it really is coming from the turbo, in my opinion the turbo ought to be removed and overhauled.
If there is significant time on the engine and you don’t know when or if the turbo has been overhauled, then again in my opinion it ought to come out and be overhauled.
I believe a cleaning / overhaul if done in a timely manner is a whole lot less expensive than a new turbo.
Plus to be honest one half of a turbo gets hot, real hot and maybe hot enough to ignite an oil leak. I don’t want to sound alarmist, but it may be a possibility.

[daletournier]

Originally Posted by Alita49DS

My Jeanneau has a 4JH3-TE which is turbo charged. There is a small amount of oil left in the tray under the engine after a number of hours of use. "Small" is hard to define as oil is a bit like blood. A little looks like a disaster. So probably less than half a cup.

The engineer who looks after the engine says that it is coming from the turbo and out of the air filter. There is indeed oil on that. And which would be consistent with there being oil on the gearbox casing at the rear of the engine. More to the point, he says that they all do it.

Is that right? Observations would be welcome.

I should say that I am not over concerned as the amount of oil to top up after several days of running (the Med really does either do dead calm or gale) is invariably from half way up the min/max on the dipstick to the max. It is just a pain having to swab the tray under the engine as it is so hard to get to. Even with the companionway steps removed.

Not as big a pain as changing in the impeller. Which the sadists at Yanmar, who put it backwards facing, combined with the sadists at Jeanneau who left minimal access.

Mine doesn't. I also share your impeller pain, which Catalina compounded.

[NoTies]

Most Yanmar turbo series have the crankcase breather terminating beside the foam air cleaner. Oil vapour condenses out and what doesn't get sucked into the engine when running soaks the foam. If yours is the same just run a hose from the breather pipe into a can.