CONDITION:
Worn turbine wheel blades (360 degrees) (Accompanied by matching wear marks on the tur
bine housing I.D.)
CAUSE:
Blade contact against turbine housing due to shaft bearing worn or failed.
RECOMMENDATION:
DO NOT REUSE:
Determine reason for bearing failure. The un
balanced condition can be the result of excessive material removal.
CONDITION:
Cracked turbine blade (minor damage shown).
CAUSE:
Foreign debris in exhaust system.
RECOMMENDATION:
DO NOT REUSE:
Further examination of the engine is required to determine the cause of the debris and eliminate it.
CONDITION:
Damaged turbine blades (major damage shown)
CAUSE:
Foreign objects from engine, such as pieces of valves or broken piston rings.
RECOMMENDATION:
DO NOT REUSE:
Determine the reason for foreign objects entering the turbocharger be fore replacement with a new assembly.
CONDITION:
Excessive oil consumption
CAUSE:
Worn, broken, or missing seal ring
RECOMMENDATION:
DO NOT REUSE:
Replace and examine other components during rebuild.
CONDITION:
Worn shaft journals
CAUSE:
Contaminated lubricating oil, overspeed, overheat, rotating imbalance or normal wear.
RECOMMENDATION:
DO NOT REUSE:
Determine the cause of contaminated oil, such as fuel dilution or extended oil change intervals.
CONDITION:
Turbine wheel/shaft assembly broken, scored and discolored
CAUSE:
Lack of lubrication to turbine bearing and shaft journal surface.
Note: Exhaust side is more sensitive to lubrication and cooling requirements due to abnormally high operating temperatures or turbocharger
overspeed.
RECOMMENDATION:
DO NOT REUSE:
Replace turbine wheel/shaft assembly. If center housing is qualified for reuse, make certain oil passages are clean and unrestricted.
CONDITION:
Turbine wheel back face cracked
CAUSE:
Excessive exhaust back pressure resulting in high exhaust temperature. Examine other engine components for cause of high exhaust back pressure.
RECOMMENDATION:
DO NOT REUSE:
Check exhaust and intake restriction according to manufacturer’s specification.