Oil Leak from Air Intake on Volvo Penta 2001

[Kasper]

I've discovered the source of (one of) the oil leaks on my Volvo Penta 2001. Like many others on online forums, it seems to be the crankcase ventilation entering the air intake, bringing oil along due to pressure in the crankcase, likely because of worn piston rings. Replacing the rings and honing isn’t on the agenda; that means pulling the engine out of the boat, and at that point, it might as well be replaced.

My question is: has anyone modified the crankcase ventilation to prevent oil from entering the air intake, perhaps by adding another ventilation point? Or any other solutions to this issue?

[Johan Leopard51]

I don’t know your motor but have some experience.

So we noticed some smoke and we noticed What looked like oil leaking from one turbo. It turned out not to be turbo lube oil leaking, it was oil from crankcase breather air settling in turbo air intake.

We have two Yanmar 8LV370. They have crankcase breather that returns crankcase air to the air intake of one of the two turbo on our units. There was no concerning oil consumption at all. Anybody that thinks their turbo diesel does not have some blowby is uninformed. Toyota and Volvo and Scania would not have crankcase breather if there was no crankcase pressure.

I am installing two ‘catch cans’ from MANN HUMMEL = Provent 200 but there are sizes for different motors. Avoid the $20 copies from China, know a guy that did that for his LandCruiser and the unit was so badly made that it warped air and it had mold debris inside. Basically you install them inline on that pipe that returns crankcase air to the turbo air intake. The catch can traps moisture and on mine I am fitting a transparent drain pipe at bottom with valve so that can see accumulation and can easily drain. One could return that oil to the motor but for now I simply want clean air turbo intake.

You should, if your motor does return air to turbo intake, avoid going complete bypass (route that air to external). The breather does need the negative air pressure created by the turbo air inlet. On my land based Scania generator it has crank case breather to atmosphere and there we installed a catch can to trap moisture before release air to atmosphere, as that oil moisture air is bad idea for the intercooler and radiator in a sound enclosed big generator situation.

The ugly cousin of crankcase breather into turbo is EGR. So having introduced oil moist air into turbo intake, the EGR returns combusted air at the air intake. “Dust” meets moist surface = caked mud gunk. I want to see how on Yanmar I can disable EGR as it anyway is not needed imho in tropics and one a boat that almost always will idle for minutes before getting under load.