Bulletin No.:

Service Bulletin

Date:

10-06-01-007E
August, 2020

TECHNICAL
Subject:

Active Fuel Management (AFM) Engine, Valve Lifter Tick Noise at Start Up When
Engine Has Been Off for 2 Hours or More (Evaluate Noise and/or Replace AFM Valve
Lifters)

Models:

2007 Buick Rainier
2009 Buick LaCrosse Super, Allure Super (Canada Only)
2007 Cadillac Escalade
Built Prior to April 1, 2006 with 6.2L Engine RPO L92 (These engines were built with
AFM Hardware but the AFM system was disabled)
2010-2011 Cadillac Escalade, Escalade ESV, Escalade EXT
2007 Chevrolet Monte Carlo
2007-2009 Chevrolet Impala
2007-2011 Chevrolet Avalanche, Silverado, Suburban, Tahoe, TrailBlazer,
TrailBlazer EXT
2010-2011 Chevrolet Camaro SS
2007-2011 GMC Envoy, Envoy XL, Sierra, Yukon, Yukon Denali, Yukon XL, Yukon XL
Denali
2007-2008 Pontiac Grand Prix
2008-2009 Pontiac G8
2007-2009 Saab 9-7X
Equipped with AFM (Active Fuel Management) and V8 Engine RPO L76, L94, L99, LC9,
LFA, LH6, LMG, LS4, LY5 or LZ1

Attention: This bulletin only applies to the AFM V8 engines listed above. It DOES NOT apply to
non-AFM Engines. If you are dealing with a non-AFM engine that is experiencing a
similar noise, refer to Engine Mechanical > Diagnostic Information and Procedures >
Symptoms in SI.
This bulletin has been revised to update the Part Number and Labor Operation. Please
discard Corporate Bulletin Number 10-06-01-007D.

Condition
Some customers may comment on an engine valve
lifter tick noise that occurs after the engine has been
shut off for at least two hours. The tick noise may last
from two seconds to ten minutes.

Cause
This condition may be caused by any of the following:
• Aerated oil in the valve lifter body, resulting in the
valve lifter being unable to purge the air quickly.
• A low engine oil level or incorrect oil viscosity.
• Dirty or contaminated oil.
• A low internal valve lifter oil reservoir level.

Copyright 2020 General Motors LLC. All Rights Reserved.

•
•

Debris in the valve lifter.
A high valve lifter leak down rate.

Correction
If the SI diagnostics do not isolate the cause of this
valve lifter tick noise and normal oil pressure is noted
during the concern, perform the following steps:
1. Inspect the engine oil condition and level. Refer to
Owner Manual > Service and Appearance Care >
Checking Things Under the Hood > Description
and Operation > Engine Oil in SI.
⇒ If the engine oil is more than one quart low, an
incorrect oil viscosity is being used or if poor
quality/contamination is observed, change the
oil and filter.

Page 2

August, 2020

Bulletin No.: 10-06-01-007E

Notice: Allow at least a two hour soak time
between engine OFF and start up when evaluating
the valve lifter tick noise.
2. Start the engine and evaluate the valve lifter tick
noise.
⇒ If the valve lifter tick noise is still present,
replace all 8 active fuel management (AFM)
valve lifters ONLY.
Refer to Valve Lifter Replacement (With AFM)
in SI.

Parts Information
Part Number

Description

Qty

12680871

AFM Hydraulic Valve Lifter

8

Warranty Information (excluding Saab
Models)
For vehicles repaired under warranty, use:
Labor
Operation

4062391

Description
Valve Lifter Replacement - Both
Sides

Labor
Time
Use
Published
Labor
Operation
Time

Warranty Information (Saab Models)
For vehicles repaired under warranty, use:
Saab Labor
Operation

21421-12

Description
Replace part,
Depressor

Failed
Object

21421

Fault/
Reason
Code

40

Location
Code

Warranty
Type

5

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.

1

Repair/
Action Code

STM
Labor Time

01 (Replace)

Use
Published
STM Labor
Operation
Time

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