BULLETIN NUMBER:
IB23-J-001B

IMPORTANT SERVICE
INFORMATION FOR:
✓ SERVICE MANAGER
✓ SERVICE ADVISOR
✓ TECHNICIAN
✓ PARTS DEPARTMENT
✓ WARRANTY PERSONNEL

ISSUE DATE:
OCTOBER 2023
GROUP:
ENGINE

REPLACEMENT LONG BLOCKS & INSTALLATION TIPS
AFFECTED VEHICLES
▪

2012 - 2020MY Isuzu N-Series Vehicles
Equipped with 6.0L Gasoline or RPO KL8 Alternative Fuel Capable
Engines

▪

2022MY Isuzu N-Series Vehicles
Equipped with 6.0L Gasoline Engines

This bulletin supersedes information bulletin IB23-J-001A. This bulletin is being
revised to update content. Please disregard previous bulletin IB23-J-001A.
INFORMATION
In the past, replacement 6.0L gasoline and RPO KL8/LC8 Alternative Fuel Capable
engines came as a certain configuration. These engines are now provided as different
long block assembly configurations. The new configurations do not include many of the
components that were provided with or pre-installed on the complete engine assemblies
previously sold as replacement parts.
NOTE: Before installing the replacement long blocks, be sure to carefully read
and understand completely all documentation included with the replacement
blocks (e.g., bulletins, installation instructions, and warnings).
The following components must be transferred from the old engine or replaced with new
components as necessary:
I = Included with engine assembly
T=Transfer from original engine if undamaged and clean
R=Replace with new
Components
Crankshaft Pulley Bolt
Crankshaft Pulley
Crankshaft Position Sensor
Camshaft Position Sensor and Wiring Harness
Camshaft Position Actuator Magnet
Engine Oil Pressure Sensor
Engine Coolant Temperature Sensor
Knock Sensors
Oil Filler Cap
Oil Level Indicator, Indicator Tube

Gasoline
I
T
T
T
T
T
T
T
T
T

KL8/LC8
I
I
I
I
I
T
T
T
T
T

Water Pump
Cylinder Heads Bypass Pipe
Exhaust Manifolds
Motor Mounts
Ignition Coils, Spark Plugs and Wires
Engine Oil Filter
Intake Manifold Assembly
Fuel injectors and rail, the throttle body, the PCV hoses,
attached sensors, and vacuum hoses
All drive belt driven components and brackets (e.g., cooling
fan, generator, vacuum pump, power steering pump, drive
belt tensioner, etc.)
The flex plate
The transmission bellhousing adapter (2022MY Only)
Oil Pan and oil pickup/screen *
Gaskets, all

T
T
T
T
T
R
T

T
T
T
T
T
I
T

T

T

T

T

T

T

T
T
R

T
T
R

*NOTE: If the old oil pan, oil pickup/screen assembly, or oil pan baffle are damaged
or contaminated with failed engine debris that cannot be completely removed, they
must be replaced with new components.

New Crankshaft Bolt

Figure 1. Gasoline Engine

Figure 2. KL8/LC8 Engine

Crankshaft Pulley Installation Tips
There are specific procedures related to removing and reinstalling the crankshaft pulley.
Please refer to the appropriate Workshop Manual for the detailed repair procedure.
Additionally, to properly remove and reinstall the crankshaft pulley, the following essential
service tools are required:
J 45059 Angle Meter
J 41816 Crankshaft Balancer Remover
J 41816-2 Crankshaft End Protector
J 42386-A Flywheel Holding Tool
J 41665 Crankshaft Balancer and Sprocket Installer
J 41478 Crankshaft Front Oil Seal Installer

Essential service tools may be purchased from isuzutrucks.service-solutions.com.

Serial Number Locations
Refer to Figures 3 and 4 for the locations of the replacement Engine Serial Numbers
(ESN) on 6.0L Gasoline engines.

Engine Serial
Number
EXAMPLE ONLY
Figure 3. Gasoline Only

Figure 4. Gasoline Label Detail

Refer to Figures 5 and 6 for the locations of the replacement Engine Serial Numbers
(ESN) on 6.0L KL8/LC8 engines.

Engine Serial
Number
EXAMPLE ONLY

Figure 5. KL8/LC8

Figure 6. KL8/LC8 Label Detail

Note: for replacement KL8 engines, the ESN can be found on labels on the oil pan
and on the cylinder head and also on a label on the packaging material for the
new engine.
The ESN is programmed into the ECM for 6.0L Gasoline and KL8/LC8 2013MY
and later.
a. An ESN is not required but is programmed into the ECM on 12K GVW
vehicles.
b. An ESN is required to be programmed into the ECM on 14.5K GVW
vehicles.
c. The Factory Installed ESN is 15 or 16 characters long, depending on the
Model Year
d. Remanufactured and replacement KL8/LC8 Engine ESNs are 8
characters long. When programming an 8-digit ESN into the ECM, place 7
or 8 zeros, as necessary, before the 8-digit serial number to fulfill the
required number of digits.
PARTS INFORMATION
Part Number
8-12729-512-0

Description
ENGINE ASM; GAS 6.0L

Application
2012-2020MY NPR/NPRHD with
6.0L RPO KL8 ‘Alternative Fuel
Capable’ option

8-19260-746-0

ENGINE ASM; GAS 6.0L

2012-2020MY NPR/NPRHD 6.0L
without RPO KL8 ‘Alternative
Fuel Capable’ option
2022 6.0L NQR/NRR GAS