Answer
System Lubricating Oil High Consumption:
External Leak Audit: Perform a physical check of the main engine external pipework, bedplate joints, crankcase door seals, supply manifolds, and pump shaft seals.
Stuffing Box / Diaphragm Seals: Inspect main engine stuffing box drains. Worn or damaged lower scraper rings will allow system oil to be drawn up into the scavenge space and burned off or drained into the slop tank.
Piston Cooling System: If pistons are system-oil cooled, check for cracked piston crowns or leaking sealing arrangements, which pass system oil directly into the combustion chamber or scavenge space.
Lube Oil Purifier & Slop System: Check the LO purifier discharge, sludge port, and water outlet. A broken water seal or incorrect gravity disc will continuously drain system oil to the sludge tank.
Lube Oil Cooler: Check expansion tank/cooling water expansion header for oil contamination, or inspect LO cooler seawater discharge for oil sheen (tube/plate perforation).
- LO sump tank surrounding: Check cofferdam/ void space around ME sump tank for any oil leakage from Sump tank