7-L16/24 GenSet

Common issues

• Fuel injector nozzle fouling or wear, leading to poor combustion and increased exhaust temperatures, especially with HFO operation.
• Exhaust valve burning or seat recession due to high temperatures or poor valve rotation, resulting in loss of compression and power.
• Turbocharger bearing wear (axial/radial play) or compressor/turbine fouling, reducing boost pressure and engine efficiency.
• Piston ring sticking or excessive wear, leading to increased blow-by, high lube oil consumption, and potential liner scuffing.
• Lube oil cooler fouling or leakage, impacting lube oil temperature control and potentially contaminating the cooling water system.
• Cooling water pump seal leakage or bearing failure, causing loss of cooling water and potential engine overheating.
• Vibration damper degradation (e.g., rubber element cracking), leading to increased torsional vibrations and potential crankshaft damage.
• Governor hunting or sluggish response, affecting engine speed stability and load sharing.

Inspection checklist

• **Visual Inspection**: Check for any leaks (fuel, lube oil, cooling water, exhaust gas) around cylinder heads, fuel pumps, turbocharger, and pipe connections. Inspect general cleanliness and condition of engine and surrounding area.
• **Gauge Readings**: Record and compare all critical parameters (L.O. pressure/temp, C.W. pressure/temp, exhaust gas temp per cylinder, turbocharger speed/boost pressure, fuel pressure) against normal operating ranges and previous records.
• **Sound and Vibration**: Listen for abnormal knocking, rattling, or hissing sounds. Check for excessive vibration on engine block, turbocharger, and generator.
• **Exhaust Gas**: Observe exhaust smoke color at stack (should be clear or light haze). Black smoke indicates poor combustion, blue smoke indicates lube oil burning, white smoke indicates water ingress or poor atomization.
• **Fuel System**: Check fuel filter differential pressure, fuel heater operation, and condition of high-pressure fuel lines for chafing or leaks. Verify quick-closing valve functionality.
• **Lube Oil System**: Check oil level, pressure, and differential pressure across L.O. filters. Review recent L.O. analysis reports for wear metals, TBN, and viscosity.
• **Cooling System**: Check expansion tank level, pressure, and temperature. Verify proper operation of cooling water pumps and heat exchangers. Check inhibitor levels.
• **Turbocharger**: Check for axial and radial play of the rotor shaft (if accessible and safe), inspect air filter condition, and look for oil leakage from compressor/turbine seals.
• **Safety Devices**: Verify functionality of emergency stop buttons and confirm alarm/shutdown settings for overspeed, low L.O. pressure, high C.W. temperature, and low C.W. pressure.
• **Generator End**: Inspect generator windings for cleanliness, check bearing temperatures, and ensure proper ventilation and earthing.

Service intervals

Typical wear limits

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

Critical spares

• Fuel injector complete unit or nozzle tips (at least one set per cylinder).
• Fuel filter elements, Lube oil filter elements (multiple sets).
• Cylinder head gasket set (complete set for one cylinder).
• High-pressure fuel pump element and delivery valve (at least one set).
• Turbocharger bearing cartridge or repair kit.
• Starting air valve (main and pilot valve).
• Exhaust valve and seat ring (at least one set).
• Various O-rings and seals (e.g., for fuel lines, cooling water lines, cylinder head).
• Sensors (e.g., L.O. pressure, C.W. temperature, exhaust gas temperature).

Safety

• **Hot Surfaces**: Exhaust manifold, turbocharger casing, and high-temperature cooling water pipes pose severe burn risks. Ensure insulation is intact and personnel are aware.
• **High-Pressure Fuel Leaks**: Pin-hole leaks in high-pressure fuel lines can create an atomized spray, leading to engine room fires (diesel spray fire). Ensure proper shielding, double-walled pipes where applicable, and regular inspection.
• **Rotating Machinery**: Exposed rotating parts like the flywheel, coupling, and fan belts present entanglement hazards. Ensure all guards are securely in place during operation.
• **Noise Levels**: Engine room noise levels typically exceed 110 dB, requiring mandatory hearing protection to prevent permanent hearing damage.
• **Starting Air System**: High-pressure air (typically 30 bar) in the starting system requires careful handling. Ensure relief valves are functional, lines are secure, and proper depressurization procedures are followed during maintenance.
• **Electrical Hazards**: The generator end presents high voltage risks. Ensure proper lockout/tagout procedures are strictly followed during any electrical maintenance or inspection.

Class survey

A class surveyor typically checks the following: 1. **Safety Devices**: Verification of overspeed trip, low L.O. pressure shutdown, high C.W. temperature shutdown, and emergency stop functionality. 2. **Fuel Oil System**: Inspection for leaks, proper insulation of hot surfaces, functionality of quick-closing valves, and fire detection/suppression systems in the vicinity. 3. **Crankshaft Deflection**: Often requested at specific intervals (e.g., 8,000-12,000 hours) to assess main bearing and crankshaft alignment. 4. **Cylinder Head Lift/Inspection**: May be required at major overhaul intervals to inspect valves, seats, and combustion chamber condition. 5. **Engine Performance**: Review of logbook data, exhaust gas temperatures, and power output to ensure satisfactory operation within design parameters. 6. **Maintenance Records**: Thorough review of planned maintenance system (PMS) records, oil analysis reports, and repair history to confirm adherence to manufacturer's recommendations. 7. **General Condition**: Overall cleanliness, absence of leaks, proper securing of components, and integrity of pipework, cabling, and insulation. 8. **Generator End**: Insulation resistance test, bearing condition, and proper earthing of the generator and associated switchgear. 9. **Starting Air System**: Inspection of air bottles, relief valves, non-return valves, and piping for integrity and proper function.