BULLETIN NUMBER:
IB12-J-005E

IMPORTANT SERVICE
INFORMATION FOR:

 SERVICE MANAGER
 SERVICE ADVISOR
 TECHNICIAN
 PARTS DEPARTMENT
 WARRANTY PERSONNEL

ISSUE DATE:
JUNE 2021
GROUP:
ENGINE

INTAKE MANIFOLD INSPECTION/REPLACEMENT
AFTER SEVERE INTERNAL ENGINE DAMAGE
AFFECTED VEHICLES


2020MY and Prior Isuzu N-Series
Equipped with 6.0L Gasoline Engine
 2022MY Isuzu N-Series Equipped with 6.0L Gasoline Engine
 2020MY - Current Isuzu N-Series Equipped with 6.6L Gasoline
Engine
This bulletin supersedes IB12-J-005D. This bulletin is being revised to update
models, model years, and to provide additional content. Please discard previous
bulletin IB12-J-005D.
INFORMATION
Severe Engine Damage
When replacing an engine due to internal damage, extreme care should be taken when
transferring the intake manifold to the engine long block. The internal engine damage may
have resulted in the potential discharge of internal engine component debris into the
intake manifold via broken pistons and/or bent, broken, or missing intake valves.
After removing the intake manifold from the engine, the technician MUST carefully inspect
all of the cylinder head intake ports to see if the valve heads are still present and not bent.
Usually when the valve heads are missing or sufficiently bent, internal engine component
debris will be present to varying degrees in the intake port of the cylinder head. If this
debris is present in any of the cylinder head ports, the intake manifold should also be
replaced.
Broken Valves, Broken Pistons, and Piston to Cylinder Head Damage
Broken Valves, Broken Pistons, and Piston to Cylinder Head damage all create material
debris that scatters throughout the induction system. If you find any damage or breakage
of this type, you MUST replace the intake manifold.
This replacement is required due to the complex inlet runner and plenum configuration of
most of the intake manifolds, making thorough and complete component cleaning difficult
and nearly impossible to verify the complete removal of debris. Reinstallation of an intake
manifold removed from an engine with deposits of internal engine component debris may
result in the ingestion of any remaining debris into the new service engine. This will cause
damage or potential failure of the new service engine long block.

Transferred Components
Additionally, when replacing an engine, ALL transferred components (such as exhaust
manifolds) should be inspected for debris. If there is any debris that cannot be completely
removed, please discuss/review with Technical Assistance or your DSPM whether the
affected component should be replaced.