C6.

6 Industrial Engine 66600001-UP(SEBP4314 - 28) - Document Structure Page 1 of 6

Turbocharger - Inspect
SMCS - 1052-040

Hot engine components can cause injury from burns. Before

NOTICE
Keep all parts clean from contaminants.

Contaminants may cause rapid wear and shortened component life.

NOTICE
Care must be taken to ensure that fluids are contained during
performance of inspection, maintenance, testing, adjusting and repair
of the product. Be prepared to collect the fluid with suitable containers
before opening any compartment or disassembling any component
containing fluids.

Dispose of all fluids according to local regulations and mandates.

Before you begin inspection of the turbocharger, be sure that the inlet air restriction is within the
specifications for your engine. Be sure that the exhaust system restriction is within the specifications
for your engine. Refer to Testing and Adjusting, "Air Inlet and Exhaust System - Inspect".

The condition of the turbocharger will have definite effects on engine performance. Use the
following inspections and procedures to determine the condition of the turbocharger.

z Inspection of the compressor and the compressor housing

z Inspection of the turbine wheel and the turbine housing

z Inspection of the wastegate

Note: Inspect the wastegate solenoid if a wastegate solenoid is installed.

Inspection of the Compressor and the Compressor Housing

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Illustration 1 g01343851
Typical example of a turbocharger

(1) Turbine housing

(2) Compressor housing

1. Inspect the compressor wheel for damage from a foreign object. If there is damage, determine
the source of the foreign object. Replace the turbocharger. If there is no damage, go to Step 2.

2. Turn the rotating assembly by hand. While you turn the assembly, push the assembly
sideways. The assembly should turn freely. The compressor wheel should not rub the
compressor housing. The turbocharger must be replaced if the compressor wheel rubs the
compressor wheel housing. If there is no rubbing or scraping, go to Step 3.

3. Inspect the compressor and the compressor wheel housing for oil leakage. An oil leak from the
compressor may deposit oil in the aftercooler. If oil is found in the aftercooler, then drain and
clean the aftercooler.

a. Check the oil level in the crankcase. If the oil level is too high, adjust the oil level.

b. Inspect the engine crankcase breather. Clean the engine crankcase breather or replace
the engine crankcase breather if the engine crankcase breather is plugged.

c. Remove the pipe for the oil drain. Inspect the drain opening. Inspect the oil drain line.
Inspect the area between the bearings of the rotating assembly shaft. Look for oil sludge.

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Inspect the oil drain hole for oil sludge. Inspect the oil drain line for oil sludge in the
drain line. If necessary, clean the oil drain line.

d. If Steps 3.a through 3.c did not reveal the source of the oil leakage, the turbocharger has
internal damage. Replace the turbocharger.

Inspection of the Turbine Wheel and the Turbine Housing

1. Inspect the turbine for damage by a foreign object. If there is damage, determine the source of
the foreign object. Replace the turbocharger. If there is no damage, go to Step 2.

2. Inspect the turbine wheel for the carbon and other foreign material. Inspect turbine housing (1)
for carbon and foreign material. Replace the turbocharger, if necessary. If there is no buildup
of carbon or foreign material, go to Step 3.

3. Turn the rotating assembly by hand. While you turn the assembly, push the assembly
sideways. The assembly should turn freely. The turbine wheel should not rub turbine wheel
housing (1) . Replace the turbocharger if turbine wheel rubs turbine housing (1) . If there is no
rubbing or scraping, go to Step 4.

4. Inspect the turbine and turbine housing (1) for oil leakage. Inspect the turbine and turbine
housing (1) for oil coking. Some oil coking may be cleaned. Heavy oil coking may require
replacement of the turbocharger. If the oil is coming from the turbocharger center housing go
to Step 4.a. Otherwise go to "Inspection of the Wastegate".

a. Remove the pipe for the oil drain. Inspect the drain opening. Inspect the area between
the bearings of the rotating assembly shaft. Look for oil sludge. Inspect the oil drain
hole for oil sludge. Inspect the oil drain line for oil sludge. If necessary, clean the drain
line.

b. If crankcase pressure is high, or if the oil drain is restricted, pressure in the center
housing may be greater than the pressure of turbine housing (1) . Oil flow may be forced
in the wrong direction and the oil may not drain. Check the crankcase pressure and
correct any problems.

c. If the oil drain line is damaged, replace the oil drain line.

d. Check the routing of the oil drain line. Eliminate any sharp restrictive bends. Make sure
that the oil drain line is not too close to the engine exhaust manifold.

e. If Steps 4.a through 4.d did not reveal the source of the oil leakage, turbocharger (3) has
internal damage. Replace the turbocharger.

Inspection of the Wastegate

When the engine operates in conditions of low boost (lug), a spring presses against a diaphragm in
the canister. The actuating rod will move and the wastegate actuator will close. The turbocharger can
then operate at maximum performance.

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When the boost pressure increases against the diaphragm in the wastegate actuator, the wastegate
actuator will open. The rpm of the turbocharger becomes limited. The rpm limitation occurs because
a portion of the exhaust gases bypass the turbine wheel of the turbocharger.

The following levels of boost pressure indicate a problem with the wastegate actuator:

z Too high at full load conditions

z Too low at all lug conditions

The boost pressure controls the maximum rpm of the turbocharger, because the boost pressure
controls the position of the wastegate. The following factors also affect the maximum rpm of the
turbocharger:

z The engine rating

z The horsepower demand on the engine

z The high idle rpm

z Inlet air restriction

z Exhaust system restriction

Note: If the engine is equipped with a wastegate solenoid, check the operation of the wastegate
solenoid. Refer to Troubleshooting, "Wastegate Solenoid -Test".

If the wastegate solenoid is not serviceable, replace the solenoid.

Check the Wastegate for Proper Operation

Table 1

Required Tools
Tool Part Number Part Description Qty
A 8T-5096 Dial Indicator Group 1

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Illustration 2 g01343854
Typical example

(1) Circlip

(2) Pin

(3) Bracket

(4) Actuator rod

(5) Nut

(6) Wastegate actuator

(7) Pipe for boost sensor

1. Disconnect the pipe for the boost sensor (7) at the wastegate actuator (6) . Connect an air
supply to the wastegate actuator that can be adjusted accurately.

2. Install Tooling (A) to the turbocharger so that the end of the actuator rod (4) is in contact with
Tooling (A) . This will measure axial movement of the actuator rod (4) .

3. Slowly apply air pressure to the wastegate so that the actuator rod (4) moves 1.0 mm (0.039
inch). Refer to Specifications, "Turbocharger" for the correct pressure for the wastegate.
Ensure that the dial indicator returns to zero when the air pressure is released. Repeat the test
several times. This will ensure that an accurate reading is obtained.

4. If the operation of the wastegate is not correct, the actuator rod (4) can be adjusted.

5. Remove Tooling (A) from the turbocharger.

6. When the air pressure is applied, loosen the nut (5) on the actuator. Remove the circlip (1) .
Remove the pin (2) from the actuator rod (4) .

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7. When the air pressure is too low, adjust the end of the actuator rod (4) in order to reduce the
length of the actuator rod (4) . If the air pressure is too high, adjust the end of the actuator rod
(4) in order to increase the length of the actuator rod (4) .

8. Install the pin (2) to the actuator rod (4) . Install the circlip (1) to the actuator rod (4) . Tighten
the nut (5) to a torque of 5 N·m (44 lb in).

9. Repeat steps 2 to 3 in order to repeat the pressure test.

10. If the air pressure is correct, remove the air supply. Remove Tooling (A) . Install the pipe for
the boost sensor (7) .

If the engine is equipped with a wastegate solenoid, then check the operation of the wastegate
solenoid.

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