Komatsu 4D98 Series Shop Manual page 114

8. Turbocharger (for 4TNE106lJ
(3) Sudden oil decrease
Cause Corrective action
1) Excessive bearing wear causing abnormalr
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Turbocharger disassembly and repair
wear or damage of seal ring
(4) Decrease in output
Cause Corrective action
1) Gas leak from any part in exhaust piping
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inspection and repair of defective portion
2) Air leak from discharge side of blower
3) Clogged air cleaner element
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Element cleaning or replacement
4) Fouled or damaged turbocharger
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Turbocharger disassembly and repair or
replacement
(5) Poor (slow) response (starting) of turbocharger
Cause
1) Hard carbon deposit on the turbine side
(wheel sealing portion) to make turbine
shaft revolution heavy
2) Incomplete combustion
Corrective action
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Turbocharger disassembly and washing with
lubricating oil replacement
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Engine combustion state inspection, followed
by improvement of combustion to normal state
(6) Abnormal sound or vibration
<Abnormal sound generation>
Cause
1) Excessively narrowed gas path due to clogged
nozzle in turbine wheel chamber or reverse
flow of blower discharge in acceleration
(generally called surging)
2) Contact rotating part
Corrective action
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Turbocharger disassembly and washing
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Turbocharger disassembly and repair or
replacement
<Vibration>
Cause Corrective action
1) Loosened intake, exhaust or oil pipe
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Turbocharger installation status check and
connection with the turbocharger repair of defective portion
2) Damaged bearing, contact between rotating
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Turbocharger disassembly with repair or
part and adjacent part, or chipping of turbine replacement, or perfect removal of forefgn
wheel or blower vane due to foreign matter in matters in case of foreign matter invasion
vasion
3) Unbalanced rotating part
0 Repair or replacement of rotating part
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