METxxSR/SRII/SRC

Common issues

• Excessive bearing wear (axial and radial play exceeding limits) leading to rotor contact or imbalance.
• Fouling or erosion of compressor and/or turbine blades, reducing efficiency and potentially causing vibration.
• Oil leakage from bearing casing, oil seals, or supply/drain lines, posing fire risk and oil consumption.
• Exhaust gas leakage from turbine casing joints, inlet/outlet flanges, or expansion bellows, reducing performance and creating hot spots.
• Malfunction or damage to the nozzle ring (if variable geometry) or nozzle ring segments, impacting engine response and efficiency.
• Failure of electronic actuators, sensors, or control linkages for variable turbine geometry (VGT) or wastegate systems.
• Rotor imbalance due to component damage, fouling, or bearing wear, leading to excessive vibration and potential catastrophic failure.
• Clogging of air filter elements (if fitted) or compressor inlet, restricting airflow and reducing boost pressure.

Inspection checklist

• Visually inspect for any signs of oil leakage from the bearing casing, oil supply/drain lines, or seals.
• Check for exhaust gas leakage from turbine casing joints, inlet/outlet flanges, and expansion joints (look for soot marks or listen for hissing).
• Inspect compressor and turbine blades (via inspection ports or boroscope) for fouling, erosion, foreign object damage (FOD), or cracks.
• Check rotor axial and radial play (if accessible and safe to do so, typically during engine shutdown) against manufacturer's limits.
• Verify the condition and cleanliness of the compressor air inlet and air filter element (if fitted).
• Inspect the water washing system components (nozzles, drain lines) for blockages, corrosion, or damage.
• Check the security of all mounting bolts, brackets, and anti-vibration elements.
• Examine the condition of insulation on hot parts of the turbine casing and exhaust piping for damage or missing sections.
• Verify the smooth operation and condition of any control linkages, actuators, or positioners for VGT or wastegate systems.
• Monitor operational parameters (boost pressure, exhaust gas temperatures, bearing temperatures if sensors are present) for abnormal readings or trends.

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 journal and thrust bearings (including bushes and thrust collar).
• Gasket and O-ring set for bearing casing, gas seals, and inspection covers.
• Oil filter elements (if separate from engine lube oil system).
• Air filter element (if applicable to the specific installation).
• Nozzle ring segments or complete nozzle ring (depending on design and common failure mode).
• Actuator/positioner for VGT or wastegate (if fitted) or critical sensor (e.g., speed sensor).
• Water washing nozzles and associated seals.

Safety

• **High Temperatures**: Exhaust gas casing and piping can reach 400-600°C. Risk of severe burns and fire if flammable materials (e.g., oil, fuel) contact hot surfaces.
• **High Rotational Speed**: Rotor operates at 15,000-30,000+ RPM. Risk of catastrophic rotor burst if imbalance, material fatigue, or foreign object damage occurs, leading to high-velocity projectile fragments.
• **Pressurized Systems**: High-pressure exhaust gas and charge air. Risk of injury from sudden release, component failure, or improper handling during maintenance.
• **Hot Lubricating Oil**: Oil supply and drain lines carry hot oil under pressure. Risk of burns, fire, and environmental pollution from leaks.
• **Noise**: High noise levels during operation, requiring mandatory hearing protection in the vicinity.

Class survey

Class surveyors typically verify the maintenance records (logbook entries, service reports, overhaul certificates), conduct a visual inspection for external oil/gas leakage, casing integrity, and security of mounting. They will check the functionality of safety devices (e.g., overspeed trip if fitted and testable), confirm operational parameters are within normal ranges, and assess general cleanliness and condition. Review of onboard critical spare parts inventory as per manufacturer's recommendations is also common.