17NA307

File in Section:
-
Bulletin No.:
Service Bulletin
17-NA-307
Date:
October, 2017
INFORMATION
Subject:
Brand:
Information On Remanufactured Engine Misfire Diagnosis After Installation
Model:
Allure
Buick
Model Year:
VIN:
from
to
2007
2011
from
GMC
Pontiac
Saturn
Transmission:
LF1, LLT, LY7
Enclave
2008
2018
LLT, LFY, LY7
LaCrosse
2007
2016
LF1, LLT, LY7
ATS
2013
2015
LFX
CTS
2007
2016
LP1, LF1, LFW,
LY7, LLT, LFX
SRX
2007
2016
LAU, LF1, LFW,
LFX, LP1, LY7
Cadillac
Chevrolet
Engine:
to
STS
2007
2011
LLT, LY7
Camaro
2010
2015
LFX, LLT
Colorado
(VIN 4)
2015
2018
LFX
Equinox
2010
2017
LF1, LFW, LFX
Impala
2012
2018
LFX
Malibu
2007
2018
LY7
Traverse
2009
2018
LFY, LLT
Acadia
2009
2016
LLT
Acadia (VIN
R, V)
2017
2017
LLT
Canyon
2015
2016
LFX
Terrain
2012
2017
LF1, LFW, LFX
G6
2007
2009
LY7
G8
2008
2009
LY7
Torrent
2008
2009
LY7
Aura
2007
2010
LY7
Outlook
2007
2010
LLT, LY7
Vue
2008
2010
LY7
Involved Region or Country
North America and N.A.Exports
Condition
The technician may experience a misfire immediately after installing a GM remanufactured HFV6 engine, usually limited to 1 bank or 1 cylinder.
Cause
This condition may be caused by the wrong camshaft being installed in the engine at the
reman facility.
Correction
If you experience this concern, inspect the camshafts to ensure the correct camshaft is
installed in each intake and exhaust position by comparing the ring strategy to either the
engine that was removed (best way) or the charts below for the engine you are
working on.
Copyright 2017 General Motors LLC. All Rights Reserved.
Page 2
October, 2017
Bulletin No.: 17-NA-307
Information
Note: Ring strategy camshaft identification is a series
of rings along the camshaft that are either simply cast
on the camshaft or machined down.
There are 5 rings on each camshaft.
Identification occurs by the order in which the machined
or cast rings are placed on the camshaft.
4870447
Top of Table is Rear of
Camshaft
M = Machined Ring (1)
HFV6 Cam Ring
strategy
Cast = Cast Ring (2)
2007–2011 (N.A.,
Holden, Suzuki) (IT
Drive)
RH EXH
RH INT
Rear of Camshaft
C
C
LH INT
LH EXH
M
C
M
C
M
C
C
C
M
C
M
M
C
C
Front of Camshaft
C
C
C
C
2007 LP1, LY7 HO (IT
Drive)
RH EXH
RH INT
LH INT
LH EXH
Rear of Camshaft
M
M
C
M
M
C
M
C
C
C
M
M
C
M
C
M
Front of Camshaft
M
C
C
M
2008-11 LLT ( IT drive,
Hollow), 2010-11
LF1/LFW
RH EXH
RH INT
LH INT
LH EXH
Rear of Camshaft
M
M
C
M
C
M
C
C
M
M
C
C
C
M
C
M
Bulletin No.: 17-NA-307
October, 2017
Page 3
Front of Camshaft
M
C
M
M
2012 LF1/LFW (new
thrust ring diameter)
RH EXH
RH INT
LH INT
LH EXH
Rear of Camshaft
M
M
C
C
C
M
C
M
M
M
C
C
C
M
C
M
Front of Camshaft
M
C
M
M
2012-2017 LFX (new
thrust ring diameter)
RH EXH
RH INT
LH INT
LH EXH
Rear of Camshaft
M
M
C
C
C
M
M
M
M
M
M
C
C
C
M
M
Front of Camshaft
M
C
C
M
2012 LY7 (new thrust
ring diameter)
RH EXH
RH INT
LH INT
LH EXH
Rear of Camshaft
C
M
C
M
C
M
C
C
C
M
C
C
M
M
C
C
Front of Camshaft
C
C
M
C
2012 and newer LLT
(new thrust ring
diameter)
RH EXH
RH INT
LH INT
LH EXH
Rear of Camshaft
M
M
C
M
C
M
C
C
M
M
C
C
C
M
C
M
Front of Camshaft
M
C
M
M
2014 and newer LF3
(vac. Pump slot,
SADI lobe)
RH EXH
RH INT
LH INT
LH EXH
Rear of Camshaft
M
M
C
M
M
M
C
C
C
M
C
M
M
M
C
M
Front of Camshaft
C
C
M
C
2018 and newer LFY
and LFX
RH EXH
RH INT
LH INT
LH EXH
Rear of Camshaft
M
M
M
C
M
M
C
M
M
C
M
M
Front of Camshaft
C
M
M
M
M
M
M
M
Page 4
October, 2017
Version
1
Modified
Released September 26,2017
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.: 17-NA-307
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