23-NA-032

Bulletin No.:
Service Bulletin
Date:
23-NA-032
March, 2023
INFORMATION
Subject:
Brand:
Information on Servicing Diesel Engines with Ceramic Glow Plugs
Model:
Cruze
Chevrolet
GMC
Model Year:
from
to
2017
2019
VIN:
from
to
Engine:
LH7
Equinox
2018
2019
LH7
Silverado 1500
2020
2023
LM2, LZ0
Silverado
2500HD/3500HD
2017
2023
L5P
Silverado
4500HD, 5500HD
and 6500HD
2019
2022
L5D
Suburban
2021
2023
LM2
Tahoe
2021
2023
LM2
Sierra 1500
2020
2023
LM2, LZ0
Sierra
2500HD/3500HD
2017
2023
L5D
Terrain
2018
2019
LH7
Yukon Models
2021
2023
LM2
Involved Region or Country
Transmission:
North America
Whenever replacing a ceramic glow plug on a diesel engine, it is required to use a glow
plug hole bore cleaning tool to remove the soot built up on the inside of the glow plug
hole. The only exception to this is when servicing a glow plug on the 2.0 L or 2.8 L diesel
engine.
Information
As the engine runs during normal operation, soot builds up between the outside of the
glow plug and the inside of the glow plug hole. Once a glow plug is removed, this soot
that collected in the bore must be removed. If not, when installing a new glow plug, the
soot could "side load" the new glow plug and induce a premature failure.
The recommended tools for cleaning these glow plug holes are as follows: 6.6 L Diesel,
3.0 L Diesel, and 1.6 L Diesel all use the EN-52074 Glow Plug Bore Reamer
Important: Service agents must comply with all
International, Federal, State, Provincial, and/or
Local laws applicable to the activities it performs
under this bulletin, including but not limited to
handling, deploying, preparing, classifying,
packaging, marking, labeling, and shipping
dangerous goods. In the event of a conflict between
the procedures set forth in this bulletin and the
laws that apply to your dealership, you must follow
those applicable laws.
Copyright 2023 General Motors LLC. All Rights Reserved.
Page 2
March, 2023
Version
1
Modified
Released March 06, 2023
GM bulletins are intended for use by professional technicians, NOT a "do-it-yourselfer". They are written to inform these
technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper
service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions, and know-how to do a
job properly and safely. If a condition is described, DO NOT assume that the bulletin applies to your vehicle, or that your
vehicle will have that condition. See your GM dealer for information on whether your vehicle may benefit from the
information.
Bulletin No.: 23-NA-032
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