Lovol 1004-4, Руководство пользователя, Страница: 73 / 87

Main reasons for the damage of turbochargers:
problems related to lubrication
foreign matters entering the turbocharger
the turbocharger running at a high temperature
poor operation or maintenance
Through carefully checking the damaged parts on turbocharger and correctly analyzing their working conditions, the
causes of the problem can be found definitely. In case it is difficult to find the causes in a short time, it is very
important to look for the reason for every single condition. If the turbocharger is damaged by outer factors, and
repaired without find the cause, then the replaced parts will also be damaged with unknown causes.
The causes will be analyzed below one by one:
1. If air leakage exist between the air outlet and the air inlet of the engine.
2. If air leakage exist at the pipe between the air inlet of the turbo and the air outlet of the exhausting pipe.
3. Too long idle speed
。
4. Too high oil pressure or oil level in the crankcase; Restriction in breather pipe of crankcase.
5. Too much blow-by of the engine.
Notes:
1. If a turbocharger has intact appearance, flexible rotor and no impeller friction that suggests that this turbocharger is
in a good status.
2. Most of the returned undamaged turbocharger is unnecessarily changed for misjudgement of oil leakage.
Problems related to lubrication:
1. use of dirty lubricating oil: dirty lubricating oil will cause abrasion of rotating shafts, bearings and bearing saddle
bores. The rotor dynamic balance is affected. And finally the turbocharger is damaged. The lubricating oil will be
contaminated due to following factors:
a. The oil filter does not fulfill requirements, or low quality canister is used.
b. The canister is broken, or the filter in the main oil gallery is choked causing the oil to flow through by-pass
valve.
c. The lubricating oil is not changed as required. And the main oil gallery is not cleaned before the change.
d. Foreign substance enters the oil gallery during replacement of the turbocharger or pre-lubricating.
e. The seal gum or sealing gasket fragments enter the main oil gallery.
2. Shortage of lubricating oil: the function of lubricating oil in the turbocharger is lubricating and cooling. The
shortage of lubricating oil will first affect the cooling capacity, overheat of turbocharger, rotor or bearing damage,
rotor dynamic balance is affected and turbocharger is damaged. Possible reasons for the shortage of lubricating oil:
a. The lubricating oil is not changed as required. The lubricating oil with viscosity grade lower than CD. As a
result, the lubricating oil is coked and malfunctions.
b. The engine stops immediately after running at high load, causing overheat of rotor and bearings, coking of
lubricating oil, and turbocharger damage.
c. The engine runs with load without first running idle after it is started. Or the engine is not pre-lubricated
before the turbocharger is replaced, causing the rotor to run without enough lubricating oil and the
turbocharger is damaged.
d. The fuel pipes or lubricating oil filter is choked, the oil pump malfunctions or the oil pressure is low.
3. Aged lubricating oil cause damage of the turbocharger.
4. Low quality or deteriorated lubricating oil.
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