Diagnostic Tips for Knocking, Rattle, Squeak and/or Squeal Type Noise from Engine – Engine Replacement Recommendations for HFV6 Gen 1 and Gen 2 – 2007-2022 Buick Cadillac Chevrolet GMC Pontiac Saturn

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Copyright 2021 General Motors LLC. All Rights Reserved.
Service Bulletin Bulletin No.: 19-NA-256
Date: August, 2021
INFORMATION
Subject: Diagnostic Tips for Knocking, Rattle, Squeak and/or Squeal Type Noise from Engine –
Engine Replacement Recommendations for HFV6 Gen 1 and Gen 2
This bulletin replaces PIP5216G. Please discard PIP5216G.
Brand: Model:
Model Year: VIN:
Engine: Transmission:
from to from to
Buick
Enclave 2008 2022
— —
3.6L (LLT, LFY)
LaCrosse 2010 2019 —
3.0L
(LF1, LFW)
3.6L (LLT,
LFX, LGX)
Regal 2018 2020 3.6L (LGX)
Cadillac
ATS 2013
2019
— —
3.6L
(LFX, LGX)
—
ATS-V 2016 3.6L (LF4)
CT4 2022 2022 3.6L (LF4)
CT5 2020 2022 3.0L (LGY)
CT6 2016 2020
3.0L (LGW)
3.6L (LGX)
CTS 2007
2019
3.0L
(LF1, LFW)
3.6L (LY7, LLT,
LFX, LGX)
CTS V-Sport 2014 3.6L (LF3)
SRX 2007 2016
2.8L (LAU)
3.0L
(LF1, LFW)
3.6L (LFX)
STS 2007 2011 3.6L (LY7, LLT)
XT5 2017 2022 3.6L (LGX)
XT6 2020 2022 3.6L (LGX)
XTS 2013 2019 3.6L (LF3, LFX)
Page 2 August, 2021 Bulletin No.: 19-NA-256
Brand: Model:
Model Year: VIN:
Engine: Transmission:
from to from to
Chevrolet
Blazer 2019 2022
— —
3.6L (LGX)
—
Camaro 2010 2022 3.6L (LLT,
LFX, LGX)
Caprice PPV 2012 2013 3.6L (LFX)
Captiva
Sport 2012 2015 3.6L (LFX)
Colorado 2015 2022 3.6L
(LFX, LGZ)
Equinox 2008 2017
3.0L
(LFW, LF1)
3.6L (LFX)
Impala
VIN W 2012 2016 3.6L (LFX)
Impala VIN 1
(including
Bi-fuel)
2014 2016 3.6L (LFR, LFX)
Impala 2017 2020 3.6L (LFX)
Malibu 2008 2012 3.6L (LY7)
Traverse 2009 2022 3.6L (LLT, LFY)
GMC
Acadia 2007
2022
— —
3.6L (LY7,
LLT, LGX)
—
Canyon 2015 3.6L
(LFX, LGZ)
Terrain 2010 2017
3.0L
(LF1, LFW)
3.6L (LFX)
Pontiac
G6 2008 2010
— —
3.6L (LY7)
—
G8 2008
2009
3.0L
(LF1, LFW)
3.6L (LY7, LLT)
Torrent 2008
3.0L (LFW)
3.6L (LLT)
Saturn
AURA 2007 2009
— —
3.6L (LY7)
VUE 2008 —
2010
3.6L (LY7)
OUTLOOK 2007 3.6L (LY7, LLT)
Involved Region or Country North America, Middle East
Condition
Some customers may comment on one or more of the following conditions:
• Knocking noise
• Seized engine
• Lower end squeak or squeal
Cause This condition may be caused by a crankshaft main or rod bearing failure.
Bulletin No.: 19-NA-256 August, 2021 Page 3
Correction
1. Verify there is metal in the engine oil by removing the oil pan.
2. Remove the main or rod bearing caps:
• If the main and/or rod bearing are not the cause of the debris, refer to SI for
further diagnostics.
3961446
3961447
• If the main and/or rod bearings are found to be the cause of the debris, before
deciding whether to replace the engine or repair it, refer to the Service
Procedure below before making that determination.
Page 4 August, 2021 Bulletin No.: 19-NA-256
Service Procedure
3961448
3961450
1. Inspect the oil control solenoids for metal debris.
This shows the oil filter is in by-pass and unfiltered
oil with bearing debris was pumped into the oil
lubrication galleys, throughout the engine.
3966789
2. Inspect for damage to the cam caps journals and
camshaft journals on the heads (obvious signs of
metal through the cap).
3961451
Bulletin No.: 19-NA-256 August, 2021 Page 5
3961452
3. Inspect the timing chain idler sprockets for stiffness
when turning (Should turn smooth and free).
Any of the above 3 instances would be cause to
replace the engine instead of repair.
While engine replacement at this point will be
necessary, additional inspections should also be made
for conditions:
– Sludging caused by lack of maintenance. Refer to
Service Bulletin# 16-NA-222.
– Global oil starvation caused by running the engine
very low on oil.
– Intentional abuse to the engine.
Important: If this is the case, then a call to the
Technical Assistance Center (TAC) is NOT required
prior to engine replacement.
If these conditions exist, warranty could be declined or
feedback made on Warranty Parts Center (WPC)
inspection. Maintenance documentation should be
obtained in these instances for warranty validation.
Clearly document your findings on your repair order, fill
out the cost worksheet, and call Product Quality Center
(PQC) only if required for your dealer.
A repair and then replacement will usually be cause for
additional inspection and scrutiny that could result in
more questioning about the repair methods.
HFV6 engines are scheduled to be returned to the
WPC for inspection to verify the concern, as well as the
information provided in the repair order to support the
engine replacement.
Version 4
Modified
Released November 13, 2019
January 14, 2021 – Added the 2021 Model Year to applicable Models.
May 24, 2021 – Added the Blazer and CT5 models.
August 20, 2021 – Added 2020-2022 XT6 (RPO LGX), 2022 CT4 (RPO LF4), 2022 Model
Year to Enclave, CT5, XT5, Blazer, Camaro, Colorado, Traverse, Acadia and Canyon and
added Middle East to Involved Region or Country section.
Additional SI Keywords: PIP5216, PIP5216A,
PIP5216B, PIP5216C, PIP5216D, PIP5216E,
PIP5216F, PIP5216G, PIP5216H, PIP5216I, PIP5216J,
PIP5216K, PIP5216L, PIP5216M
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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