23-NA-170

Bulletin No.:
Service Bulletin
Date:
23-NA-170
September, 2023
INFORMATION
Subject:
Diagnostic Tips for Seized Engine or Engine Noise
This bulletin replaces PIP5900. Please discard PIP5900.
Brand:
Model:
VIN:
2022
2023
6.2L (LT4)
2021
2023
6.2L (L87)
2023
2023
6.2L (LT4)
Camaro
2019
2023
6.2L (LT1, (LT4)
Corvette
2019
2023
6.2L (LT1,
LT4, LT2)
Express
2021
2023
6.6L (L8T)
Escalade
from
Engine:
to
CT5
Cadillac
Model Year:
from
to
Silverado 1500
2019
2023
4.3L (LV3)
5.3L (L82)
5.3L (L84)
6.2L (L87)
Silverado
2500HD/3500HD
2020
2023
6.6L (L8T)
Suburban
2021
2023
5.3L (L84)
6.2L (L87)
Tahoe
2021
2023
5.3L (L84)
6.2L (L87)
Savana
2021
2023
6.6L (L8T)
Chevrolet
Sierra 1500
2019
2023
4.3L (LV3)
5.3L (L82)
5.3L (L84)
6.2L (L87)
Sierra
2500HD/3500HD
2020
2023
6.6L (L8T)
Yukon
2021
2023
5.3L (L84)
6.2L (L87)
GMC
Copyright 2023 General Motors LLC. All Rights Reserved.
Transmission:
Page 2
September, 2023
Bulletin No.: 23-NA-170
Involved Region or Country
North America, Europe, Kazakhstan, Uzbekistan, Russia, Middle East, Iraq, Israel,
Palestine, Argentina (Mercosur), Brazil (Mercosur), Bolivia (West), Chile (West),
Colombia (West), Ecuador (West), Paraguay (West), Peru (West), Uruguay (West),
Venezuela (West), Other Central America, Japan, Cadillac Korea (South Korea), GM
Korea Company, China - SGM, Taiwan , Thailand (ASEAN), Singapore, Philippines,
Australia/New Zealand, Caribbean, Egypt, Other Africa, South Africa
Condition
Some 4.3L, 5.3L, or 6.2L engines may not crank due to being seized with possible starter
fuse being open.
Various engine noises such as but not limited to:
• Thumping (which may be perceived as upper engine noise or possibly from the
transmission)
• Knocking
• Rattling
Cause
This condition may be caused by a crankshaft bearing failure.
Bearings Diagnosis:
If any of the above issues are present and the condition has been identified as an internal
engine concern, the following may be helpful:
– Inspect the engine oil and filter for excessive metal debris, specifically bearing
material.
⇒ If bearing debris has been identified, then it will be necessary to remove the
engine oil pan for further inspection of the crankshaft rod and main bearings.
Information
If it has been found there is damage to the crankshaft bearings, please follow the latest
versions of Technical Service Bulletins 22-NA-074 and 18-NA-073 for further repair
direction.
Starter Concerns:
• If you find it necessary to replace the engine assembly, upon completion of the engine
replacement, ensure that the engine starts and runs as designed and there are no
other concerns. If the starter fuse is or was blown, replace the starter fuse and ensure
the vehicle starts up and operates as designed.
• If you noticed that the starter fuse was blown, it will be necessary to replace the starter
fuse once new engine is installed. Do not replace the starter assembly. After fuse
replacement, if you find that there may be a possible starter concern refer to
diagnostic information in service information for further details.
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.
Version
2
Modified
Released September 19, 2023
Revised September 22, 2023 - Revise Model section and added Additional Countries to
Involved Region or Country section.
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.
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