22-NA-218

Bulletin No.:
Service Bulletin
Date:
22-NA-218
November, 2022
INFORMATION
Subject:
Information on General Motors 6.2L Normal Engine Noise Concerns
Brand:
Model:
Cadillac
to
Escalade Models
2019
2023
Silverado 1500
(New Model)
2019
2019
Silverado LD
2019
2019
Silverado 1500
2020
2021
2022
2022
Silverado 1500
2023
2023
Silverado
2500HD/3500HD
2020
2023
Suburban
2019
2023
Tahoe
2019
2023
Sierra 1500
(New Model)
2019
2019
Sierra Limited
2019
2019
Sierra 1500
2020
2021
2022
2022
Sierra 1500
2023
2023
Sierra
2500HD/3500HD
2020
2023
Yukon Models
2019
2023
Silverado 1500 - LTD
(RPO J21, VIN Digit
5 = W/Y)
Chevrolet
GMC
Model Year:
from
Silverado 1500 New (RPO J22, VIN
Digit 5 = A)
Sierra 1500 - Limited
(RPO J21, VIN Digit
5 = 8/9)
Sierra 1500 - New
(RPO J22, VIN Digit
5 = H/U)
Copyright 2022 General Motors LLC. All Rights Reserved.
VIN:
from
to
Engine:
L87, L8T
Transmission:
Page 2
November, 2022
Bulletin No.: 22-NA-218
Involved Region or Country
North America, Europe, 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),
Japan, Cadillac Korea (South Korea), GM Korea Company, China - SGM, Thailand
(ASEAN), Australia/New Zealand, Other Africa
Condition
Some customers may comment that they hear different noises coming from the engine
compartment area or under vehicle which they may think are abnormal and may request
clarification of what is causing the noise. The noises may be described as a chirp,
squeak, or sputter type noise.
Information
High pitched noise described as chirp, squeak, sputter. Typically these noise occur when
spark timing is retarded. These noises are much more noticeable on the 6.2L L87 and
6.6L L8T engines as than are on the 5.3L engines. These noises can typically be heard
outside the vehicle or with windows down. Noises will come from underneath the vehicle
in the wheel well/front door area. Being next to a reflecting surface such as a wall,
guardrail or vehicle in next lane will make the noise more noticeable.
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.
Additional Information
There are 4 different types of noise that a customer
may notice. Not all vehicles will exhibit all the noises.
Refer to the table below to see what noises may be
noticeable per model year and RPO.
1. Catalyst Light Off - Occurs on start when spark
retard required for catalyst rapid warm up. Lasts
approx. 30 sec. Catalyst rapid warm up is not
triggered on all starts. Truck generally must have
sat for an hour or more.
2. Engine Restart - Engine Restart following complete
engine shutdown coasting down through
approximately 14 MPH (22 km/h). This noise will
only last for about 1 second. Spark retarded to
prevent engine overspeed/torque bump.
Version
1
Modified
Released October 31, 2022
3. Auto-Start - following start/stop engine shutdown.
The noise will last for less than a second at the end
of the auto-start. Spark retarded to prevent engine
overspeed/torque bump.
4. Throttle Blip - Light throttle blip in park/neutral. This
is rarely noticed and may be hard to produce.
Spark retarded to prevent engine overspeed.
Important: Dealers should not attempt to compare any
customer vehicles exhibiting these noises with other
similar vehicles as the noise is different from vehicle to
vehicle and this may lead to the incorrect conclusion
that the vehicle has a condition. These noises are a
normal operating characteristic of the engine. These
noises have no short- or long-term effect on the engine.
Do not attempt repairs for these noises.
Important: Replacing the engine or internal
components for this noise will not reduce or eliminate
the noise.
Please communicate to the customer that the engine is
functioning as designed and these are normal
conditions of their vehicle. Please share this
information with the customer, including a copy of this
message.
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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