6DK28 GenSet

Common issues

• Injector nozzle deposits leading to poor atomization and increased fuel consumption.
• Exhaust valve wear and burning, often exacerbated by HFO operation and poor fuel quality.
• Turbocharger contamination (fouling) on compressor and turbine sides, reducing efficiency.
• Fuel pump element wear, causing uneven fuel delivery and cylinder load imbalance.
• Cylinder liner wear, particularly at the top ring reversal point, leading to increased lube oil consumption and blow-by.
• Main and connecting rod bearing wear due to lube oil degradation or contamination.
• Cooling water system blockages or leaks, affecting engine temperature control.
• Governor malfunction, leading to unstable RPM or load fluctuations.

Inspection checklist

• Daily check of fuel viscosity and temperature at engine inlet, ensuring it's within manufacturer's specified range for the fuel type in use.
• Monitor exhaust gas temperatures for each cylinder and turbocharger inlet/outlet; look for spreads exceeding 30-40°C between cylinders.
• Verify cooling water temperatures (jacket water, charge air cooler water) are stable and within operating limits.
• Inspect fuel injectors (via indicator cock or bore scope if possible) for signs of carbon build-up or leakage; check spray pattern if removed.
• Visually inspect turbocharger for signs of fouling, oil leakage, or abnormal noise/vibration; check air filter condition.
• Check engine crankcase for abnormal pressure (blow-by) and lube oil level/condition (visual and sniff test for fuel dilution).
• Listen for abnormal noises (knocking, rattling, squealing) from cylinder units, bearings, or fuel pumps.
• Verify all safety devices (overspeed trip, low lube oil pressure, high cooling water temperature) are functional and alarms are active.
• Inspect fuel lines (especially high-pressure) for leaks, chafing, or signs of fatigue.
• Check engine mounting bolts and flexible couplings for tightness and signs of wear.

Service intervals

Typical wear limits

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

Critical spares

• Complete set of fuel injector nozzles (at least one per cylinder)
• Exhaust valve spindles and seats (at least one complete set)
• Turbocharger bearing cartridge / repair kit
• Fuel pump elements and delivery valves (at least one set)
• Various O-rings and gaskets for cylinder head, fuel system, and cooling system
• Lube oil and fuel oil filters (primary and secondary)
• Starting air valve and relief valve spares
• Engine safety sensor spares (e.g., temperature, pressure switches)

Safety

• High-pressure fuel oil leaks: Risk of spray fire, especially with HFO. Ensure all high-pressure lines are properly shielded and double-walled where required.
• Hot surfaces: Exhaust manifold, turbocharger, and cylinder heads operate at high temperatures. Risk of severe burns. Ensure insulation is intact.
• Rotating machinery: Crankshaft, flywheel, and turbocharger rotating parts pose entanglement hazards. Ensure guards are in place.
• Starting air system: High-pressure air (30 bar) can be dangerous. Proper draining of air bottles and checking relief valves is crucial.
• Noise levels: Engine room noise can cause permanent hearing damage. Personal Protective Equipment (PPE) is mandatory.

Class survey

A class surveyor will typically focus on the following: 1. **Documentation Review**: Verify engine logbooks, maintenance records, lube oil analysis reports, fuel oil bunkering records, and previous survey reports. Ensure all statutory certificates are valid. 2. **Safety Devices**: Witness testing of overspeed trip, low lube oil pressure shutdown, high cooling water temperature alarm/shutdown, and emergency stop functionality. 3. **Fuel System Integrity**: Inspect high-pressure fuel lines for leaks, proper shielding, and double-wall integrity. Check fuel oil filters, purifiers, and transfer pumps. Verify fuel oil viscosity control system is operational. 4. **Exhaust System**: Inspect exhaust manifold, bellows, and silencer for leaks, cracks, or excessive corrosion. Check exhaust gas temperature sensors. 5. **Cooling System**: Verify cooling water pumps, heat exchangers, and expansion tanks are in good condition. Check for leaks and proper temperature regulation. 6. **Engine Performance**: Review engine performance data (load, RPM, exhaust temperatures, fuel consumption) from logbooks to identify any abnormal trends. A load test may be requested if performance is suspect or after major repairs. 7. **Visual Inspection**: General inspection for oil/water leaks, abnormal vibrations, cleanliness, and proper securing of components. Check condition of engine mounts and flexible couplings. 8. **Crankcase Inspection**: If deemed necessary (e.g., high blow-by, abnormal oil analysis), a crankcase door opening for bearing inspection might be requested, especially during intermediate or special surveys. 9. **Alarms and Monitoring**: Verify all critical alarms (e.g., low lube oil pressure, high cooling water temp, high exhaust temp) are functional and correctly set.