RR

Common issues

• Compressor wheel fouling: Leads to reduced boost pressure, surging, and increased exhaust gas temperatures. Often caused by dirty intake air or oil carry-over.
• Bearing wear (axial and radial): Manifests as increased rotor play, vibration, unusual noise (whining/grinding), and potential contact between rotor and casing. Critical for rotor stability.
• Oil leakage at sealing rings: Can result in oil ingress into the compressor or turbine side, leading to fouling, or external leaks, indicating seal degradation.
• Turbine erosion/corrosion: Reduced efficiency, imbalance, and potential blade damage due to high exhaust gas temperatures, abrasive particles, or corrosive elements in exhaust.
• Exhaust gas leaks from casing joints: Reduces turbine efficiency and poses a safety hazard due to hot gas release into the engine room.
• Rotor imbalance: Caused by fouling, erosion, or bearing wear, leading to excessive vibration and accelerated bearing degradation.
• Air filter blockage: Restricts intake air flow, leading to reduced boost pressure and increased compressor suction vacuum.

Inspection checklist

• Visual inspection for oil/gas leaks: Check all casing joints, oil lines, and drain points for any signs of leakage.
• Rotor free rotation and play check: With the engine stopped and cool, manually rotate the compressor wheel to check for free movement and listen for rubbing. Check axial and radial play using a dial indicator if accessible and within manufacturer's specified limits.
• Compressor and turbine wheel condition: Inspect through intake/exhaust openings for fouling, erosion, damage (nicks, cracks), and signs of rubbing. Note any significant deposits or material loss.
• Bearing temperature monitoring: During operation, monitor bearing temperatures (if sensors are fitted) and compare with normal operating ranges (typically 60-90°C).
• Boost pressure and exhaust gas temperature monitoring: Compare current readings with engine load and historical data. Deviations can indicate turbocharger performance issues.
• Air filter condition: Inspect the air filter element for cleanliness and integrity. A dirty filter restricts airflow.
• Oil supply and drain lines: Check for kinks, blockages, or damage that could impede oil flow to or from the bearings.
• Mounting security: Verify all mounting bolts for the turbocharger and associated piping are tight and secure.

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 bearing set (thrust and journal bearings)
• Oil sealing rings (compressor and turbine side)
• Gasket and O-ring set for overhaul
• Compressor wheel nut
• Air filter element (if applicable)
• Balancing shims (for rotor balancing during overhaul)

Safety

• High temperatures: Exhaust gas casing and turbine components operate at very high temperatures (up to 600°C+). Always allow sufficient cooling time before inspection or maintenance.
• High rotational speeds: The rotor operates at extremely high RPMs (e.g., 30,000-60,000 RPM). Never attempt to inspect rotating parts while the engine is running.
• Pressurized systems: Air and exhaust gas are under pressure. Ensure systems are depressurized before opening any connections.
• Hot oil: Lubricating oil can be hot. Exercise caution when draining or handling oil.
• Hearing protection: Turbochargers generate significant noise during operation; hearing protection is mandatory in the vicinity.

Class survey

During annual or special surveys, the class surveyor will typically check the overall condition of the turbocharger, looking for external leaks (oil/gas), security of mounting, and general cleanliness. They will review engine logbook entries for turbocharger performance parameters (boost pressure, exhaust temperatures, bearing temperatures) and maintenance records, including any overhaul reports or bearing replacement documentation. The surveyor may request a check of rotor axial and radial play if there are concerns or if it's part of the engine's planned maintenance system. Functionality of any associated safety devices (e.g., overspeed trip, if fitted) and the condition of the air intake filter will also be noted.