Damage Analysis

Lubrication-Related

• 1. Dirt In Oil

  • Foreign materials in oil, metal shavings, abrasives from inadequate filtration and dilution can score the bearings and destroy the oil firm that supports the shaft. Dirty oil damages the turbocharger with heavy scoring of critical bearing surfaces.

  • cause

  • Blocked, damaged or poor quality oil filter.
  • Dirt introduced during servicing.
  • Engine wear or manufacturing debris.
  • Malfunctioning of oil filter bypass valve.
  • Poor quality oil carbonizing.

• 2. Insufficient Lubrication

  • Turbocharger rotor operates at high speed on very thin film of oil. Loss of this oil film for a repetitive short duration of 4-5 sec can lead to metal-to-metal contact, wheel-to-housing rub and turbocharger failure.

  • Indications:

  • Heat discoloration on shaft.
  • Polishing and scoring on critical surfaces such as journal/thrust bearing.

  • cause

  • Kinked / restricted / broken oil feed pipes
  • Low / no oil levels
  • Oil pump failures
  • Blocked oil filters
  • Long period of non-use
  • Oil contamination
  • Coked bearing housing
  • Failure to crank the engine after oil filter change

• 3. Foreign Object Damage

  • Foreign object damage is caused by foreign materials entering the turbine / compressor housing and impacting the turbine or compressor wheel.