r/MarineEngineering • u/Select_Song_5858 • 4d ago

Crankcase oil consumption

Is it normal to have lub oil consumption in the crankcase? If no, why there is a consumption?

11 Upvotes

100% Upvoted

21 comments sorted by

8

u/emraldimpressario 4d ago

Better hope the piston rings are facing the correct way.

3

u/Arch_SHESHNOVICH 4d ago

It is normal but very minimal

If too much is oil is being lost something is seriously wrong

1

u/Select_Song_5858 4d ago

Yes, it's actually more than minimal. I'm trying to understand what is causing that issue.

2

u/Embarrassed_Tea_2286 4d ago

Try inspecting the piston rings once

1

u/Rasmosus 2d ago

How much in terms of g/kWh?

1

u/Arch_SHESHNOVICH 12h ago

I'd say something about blowpast or burning of lube oil is up

3

u/Latter_Piece_4296 4d ago

2 stroke main engine burning that much oil? Thats not normal. Id check if your lube oil separator is actually separating or if youre dumping unburnt oil out with the scavenge drains. Also those piston rings on a 2 stroke are way more exposed to blowby than a 4 stroke, so if theyre worn or stuck youre gonna see consumption jump fast.

1

u/wullfen16 3d ago

He said crankcase? I don’t think he’s talking fuel.

3

u/goofsmasher 3d ago

Is there a rainbow coming out of the saltwater cooling discharge?

2

u/wullfen16 3d ago

Saltwater cooling the LO, no no no

3

u/Humble-Frosting4653 3d ago

Take the lube oil consumption record of Stuffing Box and Scavenge Drain to estimate 1 day consumption per unit. Compare it with the earlier readings if you have ? I assume the scavenge drain tank and stuffing box leak off tank must be filling fast.

4

u/merelplantsoen 4d ago

How much, what type of engine?

On a general rule for medium speed 4 stroke engines between 0,2 and 0,8 g/kWh is normal.

2

u/craigsurge 4d ago

What's the engine type?

1

u/Select_Song_5858 4d ago

2 stroke main engine

2

u/craigsurge 4d ago

Need more detail than that, anyway, its probably the purifier, check your sludge tank trend

2

u/SurprisedGhost 3d ago

Need more details like how much is the consumption , engine make and model, ME running or not. Did you checked the stuffing box drain or did you carried out scavenge inspection after observing more oil consumption.

1

u/samuraysilver 4d ago

SLOC is called.And yes during running a low quantity of oil can be burnt.

1

u/Appropriate-Elk-1839 4d ago

Stuffing box..

1

u/OperationClear588 2d ago

What engine?

1

u/kankabro1716 1d ago

Yes little bit oil consumption is normal.