Isuzu N-Series. Manual

Engine Mechanical (4HK1-TC) 6A-3

ISUZU DIESEL ENGINE (4HK1-TC)

Service Precautions

Matters that require attention in terms of
maintenance
To prevent damage to the engine and ensure reliability
of its performance, pay attention to the following in
maintaining the engine:

• When lifting up or supporting the engine, do not

apply a jack on the oil pan.
When taking down the engine on the ground, do
not make the bearing surface of the oil pan touch
directly the ground. Use a wood frame, for
example, to support the engine with the engine
foot and the flywheel housing.
Because there is only a small clearance between
the oil pan and the oil pump strainer, it can damage
the oil pan and the oil strainer.

• When the air duct or air cleaner is removed, cover

the air intake opening to prevent foreign matter
from getting into the cylinder. If it gets into it, it can
considerably damage the cylinder and others while
the engine is operating.

• When maintaining the engine, never fail to remove

the battery earth cable. If not, it may damage the
wire harness or electrical parts. If you need
electricity on for the purpose of inspection, for
instance, watch out for short circuits and others.

• To protect and lubricate the rotational surface

during the initial operation, apply plenty of engine
oil to it.

• When valve train parts, pistons, piston rings,

connecting rods, connecting rod bearings or
crankshaft journal bearings are removed, put them
in order and keep them.

• When installing them, put them back to the same

location as they were removed.

• Parts, such as gaskets, oil seals and O-rings, have

to be replaced by brand-new ones every time the
engine is dismantled.

• As for parts where a liquid gasket is used, remove

an old liquid gasket completely and clean it up
thoroughly so that no oil, water or dust may be
clung to them. Then, apply the designated liquid
gasket to each place anew before assembly.

• Assemble it within 7 minutes after applying the

liquid gasket.
If 7minutes or longer passed, remove the liquid
gasket and apply it again.

• When assembling or installing parts, fasten them

with the prescribed tightening torque so that they
may be installed properly.

Matters that require attention in specifically dealing
with this engine
Holes or clearances in the fuel system which serve as a
passage of fuel, including the inside of injector, are
finished extremely precisely. For this reason, they are
highly sensitive to foreign matter. If it gets inside, it can
lead to breakdown on the road. Be sure to prevent it
from getting inside.

6A-4 Engine Mechanical (4HK1-TC)

How To Read The Model

Legend

1. Engine Model

2. Engine Selial Number

Explanation of Functions and Operations
Electronic Engine Control
With the control unit, the range from injection to air
intake/exhaust, including fuel injection quantity,
injection timing, intake air restriction, EGR, and idling
rpm, is controlled.

Cylinder Block
The cylinder block is cast-iron with the center distance
of each bore being equal and is of the highly rigid,
symmetrical structure with the crankshaft center being
the center. The bearing cap is of the ladder frame
structure and tightened up under the plastic range
rotation angle method.

Cylinder Liner
The cylinder liner is selected to match an internal
diameter of a bore of the cylinder block and built, which
is imprinted on the left side of the cylinder.

Piston
The piston is aluminum-alloy and an autothermatic
piston with a strut cast, while the combustion chamber
is a round reentrant type.

Cylinder Head
The cylinder head is cast-iron and there are 4 valves
per cylinder. The angular tightening method of the
cylinder head bolt further increases reliability and
durability.

N6A6001E

Isuzu N-Series. Manual - part 474