Isuzu N-Series. Manual - part 472

6G-8 TURBOCHARGER

Exhaust Manifold

Component

Removal

1. Turbocharger as outlined previously in this section.
2. Heat shield
3. Loosen the exhaust manifold bolts, nuts and wash-

ers in numerical order shown in the illustration.

4. Exhaust manifold
5. Gaskets

Caution:

• Exhaust manifold and cylinder head for cracks or

damage to gasket surfaces.

Installation

1. Gaskets.
2. Exhaust manifold.
3. Washers nuts and bolts.

Tighten:
Exhaust manifold to 34 N

⋅m (3.5 kg⋅m/ 25 lb⋅ft)

4. Heat shield
5. Turbocharger as outlined previously in this section.

Turbocharger Turbine Housing Replace-
ment (For 4HG1-T Model)

Changing the turbine housing of the turbocharger
(integrated with the exhaust manifold)

Inspection

Before replacing the turbine housing, make sure there
are no abnormalities in other parts.

Legend

1. Heat shield

4. Exhaust manifold

2. Exhaust adapter

5. Exhaust manifold gasket

3. Turbocharger

N6A1600E

N6A1683E

TURBOCHARGER 6G-9

Notice:

• It is normal to find some oil inside the compressed-

air duct. The oil is to lubricate the turbine shaft, and
as long as the exhaust is not abnormally white in
color, this does not indicate a problem.

1. Make sure the parts have no cracks, impeded

movement, damage, or distortion of shape, that
there is no oil leakage from the seal, and that there
is no gas leakage.

2. Turn the rotor to see if it rotates smoothly, also

checking the rotation direction as well as the
amount of slack.
Refer to the separate reference sheet for the prop-
er amount of slack.
If there is an abnormality in any of the above, you
will have to change the turbocharger as a unit.

Disassembly

1. Separate the end of the actuator rod (1) from the E

Ring (2), then remove the crank (3) from the end of
the rod (1).

2. Remove the turbine housing tie-down bolts (7).

3. Separate the turbine housing from the sensor

housing.

Notice:

• Be careful not to scratch the turbine blades when

removing parts.

Inspecting the center housing assembly:
Check that none of the blades is bent, cracked, or
scratched. Make sure there are no obstructions that
would interfere with the movement of the blades or with
mounting the new housing. Remove any excess carbon
or oil.
Replacing Parts
When reassembling, be sure to replace the following
parts. (Use only genuine Isuzu parts.)

1. E Ring (2)
2. Turbine housing tie-down bolts (7)
3. Turbine housing clamp (6)
4. Adapter nut (4)
5. Adapter stud (5)

Legend

1. Compressor port

N6A1385E

N6A1386E

N6A1386E

6G-10 TURBOCHARGER

Cleaning

Thoroughly clean off the oil and carbon from abutting
surfaces, the oil passages, flange surfaces, air and ex-
haust ducts, etc. Always air-dry the parts after cleaning.

Assembly

1. Insert the sensor housing into the turbine housing.

Notice:

• When inserting the sensor housing, make sure it

will not impede the movement of the turbine
blades.

2. Apply molybdenum disulfide to the thread and un-

derside of the head of each bolt (1).

3. Temporarily secure the sensor housing in place

with the clamp (2).

4. Connect the oil side of the sensor housing (1) and

the EGR-connection side of the exhaust manifold
(2) to the angle setting gauge, then tighten the bolt
to secure the gauge in place. (The angle of the
sensor housing and turbine housing will be set with
the use of this gauge).

Turbocharger housing setting gauge: 5-8840-2673-0
(1) M6 

× P = 1.00

(2) M8 

× P = 1.25

5. To give the sensor housing some slack, loosen the

bolt on side (1) by half a turn.

6. Tighten the turbine housing tie-down bolts to the

specified torque.

Tighten:
Housing tie-down bolts to 22 N

⋅m (2.2 kg⋅m/ 16 lb⋅ft)

7. Remove the bolt that secures the pressure gauge,

then remove the gauge.

8. Manually turn the rotor clockwise to be sure it it ro-

tates smoothly. Check for abnormal noise, drag,
etc.

9. Attach the end of the actuator rod (1) to the crank

at the waste gate (3), and secure with the E Ring
(2).

10. (Indicate on the nameplate that parts were re-

placed.)

N6A1388E

N6A1389E

N6A1386E

TURBOCHARGER 6G-11

11. Pour clean oil through the oil filler port to prevent

corrosion.

12. Seal the air and exhaust ducts of the turbocharger,

as well as the water and oil filler ports to prevent
foreign matter from entering.

Follow the assembly directions to reattach to the engine.

N6A1391E