Lovol 1004-4, User Handbook Manual, Page: 74 / 87

5. Oil leakage:
Oil leakage is a common fault. The fault should be diagnosed and eliminated in time to avoid malfunction of
turbocharger. Possible reasons for oil leakage in the turbocharger:
a. The air filter or intake manifold is choked, causing excessive vacuum degree.
b. The fuel return pipe of the turbocharger is bent or damaged.
c. The carbon residual is accumulated in the fuel reservoir of center housing, causing unsmooth fuel return.
Foreign substance entering turbochargers
1. The compressor surface is damaged by foreign substance entering the former through intake manifold or air filter.
a. Poorly sealed intake pipes, causing intake air to enter the compressor without being filtered.
b. The air filter is not replaced as required or poor quality filter element is used, causing poorly filtered air.
c. Foreign substance enters the intake pipes upstream the turbocharger during engine maintenance.
2. The turbine is damaged by foreign substance from exhaust manifolds. For example:
a. Damaged parts fragments enter the turbine with exhaust gas.
b. Something as bolts drop into the exhaust manifolds during its installation, and they enter the turbine with the
exhaust gas.
Every foreign substance will influence the rotor dynamic balance, causing the rotor to choke or rotating shaft to
break.
Abnormal noises
1. gas leakage noises:
In the engine exhaust manifold, turbocharger turbine and exhaust pipes. Can be judged by exhaust traces.
In the engine intake manifolds and turbocharger compressor. Can be judged using soap solution.
2. mechanical noises:
The rotor dynamic balance is damaged.
The blades touch the turbocharger housing.
Fasteners become loose.
3. Surge: choked intake air; wrong application.
Excessive temperature
Regardless of engine running or stop, even high-quality lubricating oil will be decomposed due to excessive
temperature. As a result, carbon residual will accumulate in the whole space of center housing, blocking the oil
gallery and even the pipes. Moreover, the lubricating oil will carry the carbon residual to the bearing system,
corroding the working surface, influencing the dynamic balance, and damage the turbocharger. General reasons for
excessive temperature:
excessive exhaust gas temperature
excessive lubricating oil temperature
stopping the engine when it is still hot
blocked air filter
use of low quality lubricating oil
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