1. Compressor/Turbine Wheel Failure Modes
- Mechanical Damage
- Blade bending from improper handling or foreign object ingestion
- Fractures due to foreign object ingestion
- High-cycle fatigue (HCF) from frictional wear, blade vibration, or casting defects
- Structural Weakness
- Low-cycle fatigue (LCF) at hub-to-disk transition radius
- Hot corrosion-induced blade erosion
2. Overspeed Symptoms
- Audible Indicators
- Abnormal high-pitched noise (whine) indicating turbine wheel imbalance
- Performance Issues
- Significant power loss due to excessive RPM
- Blue/white smoke from oil burning due to bearing failure
- Mechanical Failures
- Turbine shaft fracture from exceeding rated RPM
- Oil debris in intake/exhaust pipes from bearing disintegration
3. Root Causes
- FOD Contributors
- Air filter bypass allowing ≥50μm particles
- Improper rebuild procedures introducing contaminants
- Overspeed Triggers
- Intake leaks creating excessive vacuum (>25 inHg)
- Exhaust backpressure exceeding 1.5 bar
- ECU calibration errors causing fuel over-injection
Note: All diagnostic procedures should be performed using OEM-approved tools and reference materials.
