MAN TCR18

Common issues

• Bearing wear (thrust and journal bearings) due to high rotational speeds, insufficient lubrication, or contamination, leading to increased axial/radial play and potential shaft damage.
• Fouling of compressor wheel and diffuser by oil mist or airborne contaminants, reducing efficiency and potentially causing surging.
• Fouling and erosion of turbine blades and nozzle ring by exhaust gas particulates and high temperatures, leading to reduced power output and increased exhaust gas temperatures.
• Corrosion of casing components (especially compressor casing and water-cooled sections) due to saltwater exposure or condensation, compromising structural integrity and sealing.
• Malfunction of electronic control components (e.g., speed sensors, actuators for variable turbine geometry if fitted) due to vibration, moisture ingress, or aging, affecting turbocharger performance and engine control.
• Oil leakage from bearing housing seals, indicating seal wear or excessive bearing play, leading to oil consumption and potential fire hazard.
• Cracks in turbine casing or exhaust gas manifold connections due to thermal stress and vibration, causing exhaust gas leaks and reduced efficiency.

Inspection checklist

• Check axial and radial play of the rotor shaft (cold and warm if possible) against manufacturer's limits. Typical new axial play: 0.1-0.3 mm, service limit: 0.4-0.6 mm. Radial play: 0.08-0.2 mm, service limit: 0.3-0.4 mm.
• Visually inspect compressor wheel for fouling, erosion, bent blades, or foreign object damage (FOD). Check for rubbing marks on the casing.
• Visually inspect turbine blades and nozzle ring (if accessible without full disassembly) for fouling, erosion, cracks, or signs of overheating. Check for free movement of nozzle ring segments if VGT equipped.
• Inspect turbocharger casing for external cracks, exhaust gas leaks, oil leaks, and secure mounting bolts. Check condition of insulation blankets.
• Verify lubricating oil supply and drain lines for leaks, proper flow, and cleanliness. Check oil pressure and temperature at turbocharger inlet.
• Inspect air filter condition and ensure air intake is clear. Check functionality of water washing system (if fitted).
• Check functionality of overspeed trip device (if mechanical) or verify speed sensor readings against engine RPM. Inspect actuator for variable turbine geometry (if fitted) for smooth operation.
• Monitor exhaust gas temperatures before and after the turbine, and boost pressure, comparing to engine load and historical data for performance deviations.
• Check condition of vibration dampers and mounting feet for signs of wear or damage.

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 cartridge assembly (thrust and journal bearings)
• Set of O-rings and gaskets for casing and oil lines
• Oil filter elements (if applicable to turbocharger's oil system)
• Speed sensor and associated wiring
• Nozzle ring segments (if VGT type and prone to wear/fouling)
• Actuator repair kit (if VGT type)
• Compressor wheel nut and locking washer

Safety

• High surface temperatures (up to 500°C on turbine casing) posing severe burn hazards. Ensure insulation is intact.
• High-speed rotating components (up to 60,000-100,000 RPM) present a risk of disintegration if bearings fail or foreign objects enter, leading to catastrophic damage and potential injury.
• High noise levels (100-120 dB) requiring hearing protection in the vicinity during operation.
• Risk of exhaust gas leaks (CO, NOx) from casing or manifold connections, leading to asphyxiation or fire hazard in enclosed spaces.
• Oil leaks from bearing housing can create slip hazards and increase fire risk on hot surfaces.

Class survey

The class surveyor will typically review maintenance records, running hours, and any reported defects. They will conduct an external visual inspection for leaks (oil, exhaust gas), cracks, and secure mounting. Key checks include verifying rotor axial and radial play, inspecting the condition of the air filter, checking the functionality of the overspeed trip device (if fitted), and confirming the integrity of the lubricating oil system and cooling water connections. Performance parameters like boost pressure and exhaust gas temperatures may be reviewed against design values. The surveyor will also ensure compliance with fire safety regulations regarding insulation and oil containment.