8LEL35

Common issues

• Fuel injection system wear and clogging (injectors, fuel pumps) due to HFO operation and varying fuel quality, leading to poor combustion and increased exhaust temperatures.
• Exhaust valve burning and seat wear, often exacerbated by high thermal loads, poor fuel quality, and inadequate cooling or lubrication.
• Cylinder liner wear (scuffing, ovality, taper) from abrasive combustion byproducts, especially with HFO, and potential issues with lube oil distribution.
• Turbocharger bearing wear, fouling of compressor and turbine sides, leading to reduced efficiency, surging, and increased exhaust back pressure.
• Main and crankpin bearing wear due to lube oil degradation, contamination, or misalignment, potentially leading to excessive clearances and vibration.
• Cooling system issues: fouling of heat exchangers (lube oil, jacket water), leaks in piping, and corrosion, impacting engine thermal management.
• Governor malfunction: mechanical governors can become sluggish or inaccurate over time, affecting engine speed control and load response.

Inspection checklist

• Visual inspection for any leaks (fuel, lube oil, cooling water, exhaust gas) around the engine, piping, and connections.
• Monitor critical operational parameters: individual cylinder exhaust gas temperatures, lube oil pressure/temperature, jacket cooling water pressure/temperature, fuel pressure/temperature, and turbocharger RPM/boost pressure. Look for deviations or trends.
• Check engine room for abnormal noises, vibrations, or smells (e.g., burning oil, fuel, or exhaust).
• Inspect crankcase for abnormal oil mist, water ingress (via sight glasses or drain), or metallic particles in the sump oil (if safe and accessible).
• Verify fuel system integrity, including proper heating, filtration, and absence of leaks from high-pressure lines (check shielding).
• Observe exhaust gas condition from the stack for excessive smoke (color, density) indicating combustion issues.
• Confirm proper functionality of engine safety devices: overspeed trip, low lube oil pressure trip, high cooling water temperature trip, and remote/local stop mechanisms.
• Inspect engine foundation bolts for tightness and signs of movement or corrosion.
• Check general cleanliness of the engine and surrounding area, ensuring no combustible materials are near hot surfaces.

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 Nozzles (at least 2 per cylinder, or 1 complete set)
• Exhaust Valve Spindles & Seats (at least 1-2 sets)
• Piston Rings (1-2 sets per cylinder, especially top ring)
• Main & Crankpin Bearing Shells (at least 1 set of each size)
• Turbocharger Bearing Cartridge or complete repair kit
• Fuel Pump Plunger & Barrel (1-2 sets)
• High-Pressure Fuel Pipes (at least 1-2 spares)
• Assorted O-rings, gaskets, and seals for critical systems (fuel, lube oil, cooling water)

Safety

• Hot surfaces: Exhaust manifold, turbocharger, HFO lines, and steam lines pose severe burn risks. Ensure proper insulation and warning signs.
• High-pressure fuel lines: Rupture can lead to a fine spray of highly flammable fuel, creating an immediate fire hazard. Ensure proper shielding and regular inspection.
• Crankcase explosion: Accumulation of oil mist can ignite, leading to a violent explosion. Verify proper functioning of oil mist detectors and crankcase relief valves.
• Rotating machinery: Flywheel, coupling, and other rotating parts present entanglement and impact hazards. Ensure guards are in place and maintained.
• Starting air system: High-pressure air and potential for uncontrolled engine starts. Adhere strictly to starting procedures and ensure safety interlocks are functional.

Class survey

A class surveyor will typically focus on verifying the engine's structural integrity, operational safety, and compliance with statutory regulations. Key checks include: 1. **Documentation Review:** Scrutiny of engine logbooks, planned maintenance records, previous survey reports, and statutory certificates. 2. **Safety Device Testing:** Functional testing of overspeed trip, low lube oil pressure alarm/trip, high cooling water temperature alarm/trip, and main engine remote/local stop mechanisms. 3. **Crankcase Safety:** Inspection and functional test of oil mist detector, crankcase relief valves, and explosion doors. 4. **Fuel System Integrity:** Close inspection of high-pressure fuel pipes for proper shielding, leaks, and signs of wear. Verification of fuel oil supply/return lines for integrity and fire insulation. 5. **Lubrication & Cooling Systems:** Inspection of pumps, coolers, filters, and piping for leaks, corrosion, and proper operation. Lube oil analysis reports may be requested. 6. **Starting Air System:** Verification of starting air pressure, relief valve settings, non-return valves, and compressor functionality. 7. **Engine Foundation:** Visual inspection of holding down bolts for tightness, signs of movement, and corrosion. 8. **Exhaust System:** Inspection of exhaust manifold, bellows, and silencer for leaks, cracks, or damage. 9. **Operational Test:** Observation of the engine running at various loads, checking critical parameters, and response to control commands. 10. **Specific Measurements (Intermediate/Special Survey):** Crankshaft deflection measurements are often required. Cylinder liner wear measurements may be requested if performance issues are noted or as part of a planned maintenance review.