6RT-flex96C-D

Common issues

• Exhaust temperature spread between cylinders exceeding acceptable deviation, pointing to injector, exhaust valve or fuel timing issues
• Common-rail fuel injection valve wear/leakage causing poor combustion or increased smoke
• Exhaust valve spindle/seat wear leading to blow-by and loss of compression
• Piston ring and liner wear affecting lube oil consumption and blow-by
• Turbocharger fouling on the compressor or turbine side reducing scavenge air pressure
• Crosshead/guide shoe wear from lubrication film breakdown
• Cylinder liner cold corrosion from extended low-load running with poor cooling water temperature control
• Scavenge fire risk from oil/soot accumulation in the scavenge space

Inspection checklist

• Check exhaust gas temperature deviation between cylinders against baseline
• Inspect cylinder liner bore for wear (liner wear gauge) and scuffing marks
• Check piston rings for wear, gap and sticking during scheduled overhaul
• Inspect exhaust valve spindle, seat and rotator condition
• Check common-rail fuel injection valves for spray pattern and leakage
• Inspect crosshead bearing and guide shoe clearance
• Check turbocharger compressor and turbine blades for fouling/erosion and bearing condition
• Inspect the scavenge space for oil/soot accumulation and check scavenge drain function
• Verify crankshaft deflection readings against the maker's limits
• Check main and crankpin bearing shells for wear pattern at scheduled opening

Service intervals

Typical wear limits

Ranges are typical for this design class. Always confirm against the manufacturer documentation for your serial number.

Critical spares

• Piston ring set per cylinder
• Spare cylinder liner
• Exhaust valve spindle and seat
• Complete fuel injection valve
• Crosshead bearing shells / guide shoes
• Main and crankpin bearing shells
• Turbocharger nozzle ring / bearing cartridge for the fitted turbocharger

Safety

• Crankcase explosion risk from oil mist/hot spots - relief doors and oil mist detection must be maintained and tested; never work inside the crankcase without confirming it is cold and isolated
• Scavenge space fire risk from accumulated oil/soot - follow the maker's scavenge fire procedure and keep drains clear
• High-pressure common-rail fuel system (several hundred bar) - depressurize and lock out before any injection system work
• Rotating/reciprocating parts at very high torque - full lockout/tagout and barring gear interlock before entering the engine
• Starting air system pressure vessels - inspect and relieve per maker instructions before opening

Class survey

Main propulsion 2-stroke engines fall under Continuous Machinery Survey in most class societies, with crankshaft deflection readings, bearing clearances and piston/liner condition checked against an approved planned maintenance schedule; keep cylinder condition reports, deflection logs and lube oil analysis trends on hand, as surveyors commonly cross-check these against the engine running-hours log.