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Failure:
Piston ring fracture
Cause: Exceptionally high
combustion pressure, as may be caused by advanced injection pump
timing, over use of aerosol starting aid, increased compression ratio
Symptom: Loss of power.
Oil consumption. Emission of fumes from engine breather
Solution: Establish
cause and take remedial action. Replace piston assembly
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Failure: Piston ring scuffing, or localized
areas of piston ring seizure
Cause: Excessive cylinder surface
temperature. Marginal lubrication, particularly during early engine
life. Cylinder bore distortion
Symptom: Oil consumption, with possible
fumes from engine breather
Solution: Rectify
any cylinder bore damage. Replace piston rings, also the piston, if
necessary. Ensure the complete engine lubrication system is fully
primed (oil pump, filter, etc.) Observe running in procedures as
recommended by the engine manufacturer
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Failure: Fracture of cylinder liner in the under flange area
Cause: Incorrect distribution of
pressure of liner flange, as may be caused by: Cylinder block distortion.
Incorrect tightening of cylinder head studs. Misaligned block
counter bore. Foreign material assembled under
Symptom: Combustion gases
ventilating to coolant. Engine noise. Eventual destruction of liner
Solution: Establish
cause and take corrective action. replace cylinder liner and any other
affected components
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Failure:
Erosion and burning of piston crown
Cause: Incorrect fuel injection,
injection timing, over fueling, damaged or incorrectly located injector
Symptom: Loss of power, emission
of fumes from engine breather. Exhaust smoke
Solution: Inspect
and correct fuel injection equipment and timing, check and correct any
damage to cylinder bore. Replace piston
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Failure: Pitting and erosion of liner outer surface
Cause: High frequency vibration resulting in cavitations
erosion. this may be promoted by general engine wear or
repetitive use for long periods at higher than normal engine loads
Symptom: Loss of coolant
Solution: Clean
and cheek sealing ring grooves and contact areas. Replace cylinder liner.
Ensure that the coolant system is operating at the correct pressure. Use
coolant inhibitors as recommended by the engine
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Failure: Piston seizure, with severe damage to the top land
Cause: Exceptionally high combustion
temperature. Malfunction of piston oil cooling jets (in engine
incorporating this equipment). These cause seizure close to the
piston crown, which may result in piston damage and progression of seizure
down the piston skirt
Symptom: Loss of power. Engine noise. Fumes from
engine breather
Solution: Check
adjustment o fuel injections equipment and correct as necessary. Rectify
or replace damaged cylinder components. Ensure any piston under crown
cooling jets are functioning correctly
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Failure: Cylinder liner bore distortion. Scuffing or seizure of
piston and piston ring. Carbon deposits on outside of cylinder
liner
Cause: Cylinder block distortion. Cylinder head
distortion. Damage or incorrectly fitted cylinder had gasket. Incorrect
liner fitting
Symptom: Loss of power. Oil consumption. Fumes
from engine breather. Piston seizure in extreme cases
Solution:
Thoroughly clean the engine block bores. Check for block bore distortion
and rectify if possible
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Failure:
Erosion of piston skirt adjacent to piston hole. damage to
cylinder bore
Cause: Incorrect assembly of circlip. Fitting of
used circlips. End pressure transmitted via the piston pin, possibly
associated with connecting rod mis-alignment, tapered crank journals, or
excessive crankshaft end float. Foreign material assembled in piston pin
bore
Symptom: Engine noise. Oil consumption
Solution: Correct
any cylinder bore damage. Check and correct any connecting rod or small
end bush mis-alignment. Check for and correct any crankshaft end float.
Replace piston assembly, ensuring that the circlips are correctly located |
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Failure: Cracks radiating from the combustion bowl
Cause: Extremes of temperature applied to piston
crown, resulting in thermal shock. may be promoted by exceptionally high
engine load when operating in low ambient temperature
Symptom: Cannot be detected during normal engine
operation
Solution: Replace
damaged components
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Failure: Piston seizure, with severe damage concentrated in the lower
area of piston skirt
Cause: a) Damaged concentrated on one face: Lack
of lubrication. b) Damage on both faces: Progression of damage caused by
lack o lubrication. Insufficient piston to cylinder clearance. Cylinder
bore distortion. General engine overheating. Restricted coolant
circulation
Symptom: Loss of power. Engine noise. Fumes from
engine breather
Solution: Inspect
cylinder bore and coolant circulation. Correct as necessary. Replace
damaged cylinder components
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