A100-M 100-M42

Common issues

• Bearing wear or failure (journal and thrust bearings) leading to increased axial/radial clearances and potential rotor contact.
• Compressor fouling due to dirty intake air or oil carry-over, reducing air flow and boost pressure.
• Turbine fouling (sooting) and erosion of nozzle ring and turbine blades, impacting efficiency and exhaust gas flow.
• Oil leakage from bearing housing seals, indicating seal wear or improper oil drain conditions.
• Rotor imbalance or vibration due to fouling, blade damage, or bearing issues, causing abnormal noise and potential structural damage.
• Cracks in turbine or compressor casings, often due to thermal stress, vibration, or foreign object damage (FOD).
• Surging, indicated by fluctuating boost pressure and characteristic 'whooshing' sound, often caused by engine load changes, air filter blockage, or severe fouling.

Inspection checklist

• Monitor bearing oil inlet/outlet temperatures and pressures; check for abnormal deviations from manufacturer's specified ranges.
• Visually inspect for oil leaks around the bearing housing, oil supply/drain lines, and casing joints.
• Check for abnormal noise or vibration during operation; use a stethoscope or vibration meter if available.
• Inspect the compressor wheel (via air filter opening) for fouling, erosion, or blade damage. Ensure air filter is clean and intact.
• Inspect the turbine wheel and nozzle ring (via inspection port) for fouling, erosion, or foreign object damage.
• Verify exhaust gas temperatures before and after the turbine; significant deviations can indicate fouling or damage.
• Check axial and radial rotor clearances during planned maintenance or if vibration is suspected, comparing to manufacturer's limits.
• Inspect casing for any signs of cracks, deformation, or excessive heat discoloration.
• Ensure all safety guards and insulation covers are in place 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 (journal and thrust bearings, including sleeves and O-rings).
• Gasket and O-ring set for bearing housing and casing covers.
• Oil filter elements (if applicable to turbocharger's oil system).
• Nozzle ring (especially if operating on heavy fuel oil or known for rapid fouling/erosion).
• Rotor shaft balancing weights (for re-balancing during overhaul).
• Overspeed trip sensor/actuator (if fitted).

Safety

• High surface temperatures of turbine casing and exhaust piping (burn hazard).
• High rotational speeds of the rotor (up to 60,000+ RPM) pose a catastrophic failure risk, potentially ejecting high-velocity fragments.
• Pressurized systems (exhaust gas, charge air, lubricating oil) can cause injury if lines or casings fail.
• High noise levels during operation require hearing protection in the vicinity.
• Hot exhaust gas leaks can cause burns and create an oxygen-deficient atmosphere.

Class survey

Class surveyors typically verify the turbocharger's maintenance records, including running hours, bearing replacements, and major overhauls. They will visually inspect for external damage, oil leaks, and excessive vibration. Performance parameters (boost pressure, exhaust gas temperatures, bearing temperatures) from logbooks are reviewed. The condition of air intake filters, exhaust gas ducting, and insulation is checked. If an overhaul has recently been performed or is due, the surveyor may request to see relevant documentation, including clearance measurements and balancing certificates. Confirmation of overspeed trip functionality (if fitted) and general cleanliness of the unit is also part of the inspection.

Estimated lifetime: 16,000 - 24,000 running hours before major overhaul is typically required, with proper maintenance.