19NA256

Service Bulletin
Bulletin No.:
19-NA-256
Date:
May, 2021
TECHNICAL
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:
Enclave
Buick
Model Year:
VIN:
from
to
2008
2021
3.6L (LLT, LFY)
3.0L
(LF1, LFW)
3.6L (LLT,
LFX, LGX)
LaCrosse
2010
2019
Regal
2018
2020
3.6L (LGX)
ATS
2013
2019
3.6L
(LFX, LGX)
ATS-V
2016
CT5
2020
2021
3.0L (LGY)
CT6
2016
2020
3.0L (LGW)
3.6L (LGX)
CTS
2007
Cadillac
CTS V-Sport
—
to
Engine:
from
—
—
3.6L (LF4)
2019
—
—
3.0L
(LF1, LFW)
3.6L (LY7, LLT,
LFX, LGX)
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
2021
3.6L (LGX)
XTS
2013
2019
3.6L (LF3, LFX)
Copyright 2021 General Motors LLC. All Rights Reserved.
Transmission:
—
Page 2
Brand:
Chevrolet
May, 2021
Model:
Model Year:
Bulletin No.: 19-NA-256
VIN:
from
to
Blazer
2019
2021
3.6L (LGX)
Camaro
2010
2021
3.6L (LLT,
LFX, LGX)
Caprice PPV
2012
2013
3.6L (LFX)
Captiva
Sport
2012
2015
3.6L (LFX)
Colorado
2015
2021
3.6L
(LFX, LGZ)
Equinox
2008
2017
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
2021
3.6L (LLT, LFY)
Acadia
2007
Canyon
2015
—
to
—
Pontiac
Saturn
3.0L
(LFW, LF1)
3.6L (LFX)
—
—
3.6L
(LFX, LGZ)
Terrain
2010
2017
3.0L
(LF1, LFW)
3.6L (LFX)
G6
2008
2010
3.6L (LY7)
G8
2008
2009
3.0L
(LF1, LFW)
3.6L (LY7, LLT)
Torrent
2008
AURA
2007
VUE
2008
OUTLOOK
2007
Transmission:
—
3.6L (LY7,
LLT, LGX)
2021
GMC
Engine:
from
—
—
—
—
3.0L (LFW)
3.6L (LLT)
2009
2010
3.6L (LY7)
—
—
3.6L (LY7)
3.6L (LY7, LLT)
—
Bulletin No.: 19-NA-256
May, 2021
Involved Region or Country
North America
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.
Page 3
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.
Correction
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
May, 2021
Bulletin No.: 19-NA-256
Service Procedure
3966789
3961448
2. Inspect for damage to the cam caps journals and
camshaft journals on the heads (obvious signs of
metal through the cap).
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.
3961451
Bulletin No.: 19-NA-256
May, 2021
3961452
3. Inspect the timing chain idler sprockets for stiffness
when turning (Should turn smooth and free).
Page 5
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
3
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.
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.
WE SUPPORT VOLUNTARY
TECHNICIAN
CERTIFICATION