Page 233 of 715
04-51719-00
3) Troubleshooting Sequence
The basic checks for intake system are as follows:
Basic Checks for Intake System ▶
Make sure to replace or clean the air cleaner
element periodically. Otherwise, engine will be
derated or work abnormally because of low
intake air volume.
Unlike the fuel system, which is a closed
circuit, the intake system is an open circuit
system. Therefore any malfunction may occur
due to dust and dirt.
Most of the connections consist of hoses so
the system cannot withstand high temperature
and pressure. Also it can be deformed or
loosened easily because it is a clamp
mounting system. Thus, when checking the
engine, basic inspections, such as tightened
status check and visual inspection for hose,
etc., should be carried out in advance.
Other Checks for Intake System ▶
If the intake system is free of any faults,
check for EGR and PCV oil separator.
Page 245 of 715

06-4
2. INSPECTION
1) Cautions During Driving
The following lists cautions to take during test drive and on the turbocharger vehicle, which must
be considered during the operation.
It's important not to drastically increase the engine rpm starting the engine. It could make
rotation at excessive speed even before the journal bearing is lubricated and when the
turbocharger rotates in poor oil supply condition, it could cause damage of bearing seizure
within few seconds.
If the engine is running radically after replacing the engine oil or oil filter brings poor oil supply
condition. To avoid this, it's necessary to start off after idling the engine for about 1 minute
allowing oil to circulate to the turbocharger after the replacement.
When the engine is stopped abruptly after driving at high speed, the turbocharger continues to
rotate in condition where the oil pressure is at '0'. In such condition, an oil film between the
journal bearing and the housing shaft journal section gets broken and this causes abrasion of
the journal bearing due to the rapid contact. The repeat of such condition significantly reduces
life of the turbocharger.
Therefore, the engine should be stopped possibly in the idle condition. 1.
2.
3.
After string for long period of time during winter season or in the low temperature condition
where the fluidity of engine oil declines, the engine, before being started, should be cranked
to circulate oil and must drive after checking the oil pressure is in normal condition by idling
the engine for few minutes.
Page 252 of 715

06-111914-01
3. TROUBLESHOOTING
The followings are cautions to take in handling defects of turbocharger, which must be fully aware
of.
1) Cautions
After stopping the engine, check whether the bolts on pipe connecting section are loose as
well as the connecting condition of vacuum port and modulator, which is connected to the
actuator.
During idling of the engine, check for leakage in the connecting section of pipe (hoses and
pipes, duct connections, after the turbocharger) by applying soap water. The leakage condition
in the engine block and turbine housing opening can be determined by the occurrence of
abnormal noise of exhaust.
By running the engine at idle speed, abnormal vibration and noise can be checked.
Immediately stop the engine when abnormal vibration and noise is detected and make
thorough inspection whether the turbocharger shaft wheel has any damages as well as
checking the condition of connections between pipes.
In case where the noise of engine is louder than usual, there is possibility of dampness in the
areas related with air cleaner and engine or engine block and turbocharger. And it could affect
the smooth supply of engine oil and discharge.
Check for damp condition in exhaust gas when there is sign of thermal discoloration or
discharge of carbon in connecting area of the duct.
When the engine rotates or in case where there is change in noise level, check for clogging of
air cleaner or air cleaner duct or if there is any significant amount of dust in the compressor
housing.
During the inspection of center housing, inspect inside of the housing by removing the oil drain
pipe to check for sludge generation and its attachment condition at shaft area or turbine side.
Inspect or replace the air cleaner when the compressor wheel is damaged by inflow of foreign
materials.
Inspect both side of the turbocharger wheel after removing inlet and outlet pipe of the
turbocharger. 1.
2.
3.
4.
5.
6.
7.
8.
9.
Page 648 of 715
11-10
Oil Pump Pressure Check ▶
Check the oil pump pressure to locate any defect
in oil pump.
Before checking the pressure, check the oil
level and belt tension. Prepare the empty
container to collect the spilled oil during the
service.
Unscrew the pressure line fitting in power
steering pump.
Install the pressure gauge between the
power steering pump and the power steering
oil pressure line.
Place the shift lever to neutral position. Apply
the parking brake.
Open the valve in pressure gauge. Start the
engine and let it run at idle speed.
Turn the steering wheel several times so that
the oil temperature reaches to normal
operating level. A.
B.
C.
D.
E.
Fully close the valve in pressure gauge and
measure the oil pressure. F.
To prevent internal damage, do not close the
gauge valve over 10 seconds.
Keep the oil temperature at proper range. -
-
Relief pressure90 ± 3 bar