Bulletin No.:

Service Bulletin

Date:

16-NA-003
March, 2023

TECHNICAL
Subject:

Chirp, Squeak Noise from Rear of Vehicle

Brand:

Cadillac

Chevrolet

Model:
ATS-V
Series
CTS-V
Series

Model Year:
from

VIN Breakpoint:
to

from

to

2019

—

—

Engine:

Transmission:

All

All

2016

Camaro

2016

Corvette

2014

Involved Region or Country

North America Only

Additional Option (RPOs)

Chevrolet – Equipped with LT4 Engine, LGX Engine / NPP Exhaust, LT1 Engine / N10
Exhaust or LT1 Engine / NPP Exhaust
Cadillac – Equipped with LF4 or LT4 Engine

Condition

Some customers may comment on hearing a squeak or chirp noise coming from the rear
of the vehicle. The noise may be reported as being intermittent.

Cause

The noise may be caused by the opening/closing of the exhaust valves during normal
performance.

Correction
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.
Note: There is a normal, audible noise associated with
the opening/closing of the exhaust valves. The squeak/
chirp noise noting the condition is an additional, more
shrill noise, and may be intermittent, influenced by
temperature and humidity.
Confirm that the front or rear/tail pipe valves are the
cause of the condition by activating the flow control
function of the exhaust system.
1. Raise and support the vehicle. Refer to Lifting and
Jacking the Vehicle in SI.
2. Use GDS to verify the exhaust flow control valves
open and close when commanding the Exhaust
Flow Control Valve On and Off with a scan tool.
3. For Camaro and Corvette models, the engine
sound management setting must be set to “Auto” to
enable the scan tool to operate the valves.
Copyright 2023 General Motors LLC. All Rights Reserved.

Note: The noise may only occur during valve opening
OR closing of a valve, not always both.
4. Command the flow control functioning numerous
times and listen for any squeak/chirp noise, over
and above the normal activation noise.
5. If the squeak/chirp noise is evident, continue
ahead to the lubrication Service Procedure below.

Page 2

March, 2023

Bulletin No.: 16-NA-003

Service Procedure

4340727
4340714

Important: Regardless the noisy valve location,
lubricate ALL exhaust valves on the system.
Generously lubricate the forward, and rear if equipped,
exhaust valves following the steps below:
1. Fully raise the vehicle.

3. Apply DRY SLIDE Multi-Purpose Dry Lubricant, P/
N 1052948 (in Canada, use 89021511), into the
valve by inserting the nozzle into the slot on the
valve. Liberally apply a generous amount of the
lubricant.

4340730
4340724

2. Position a drop cloth below the valve being
lubricated.

4. Move the drop cloth to and repeat application at
both, or all four valve locations, depending on the
exhaust system.
5. With all valves lubricated, command the flow
control functioning numerous times on all valves,
to work the lubricant into the valve.
6. During the flow control functioning, also verify the
squeak/chirp noise has been eliminated.

Bulletin No.: 16-NA-003

March, 2023

Page 3

Parts Information
Description

Part
Number

LUBRICANT, DRI-SLIDE, 4
OZ AEROSOL VOC
COMPLIANT
LUBRICANT, DRI-SLIDE,
149 G (Canada)

01052948
P/N
89021511
(Canada)

Qty

1

Warranty Information
For vehicles repaired under warranty, use:
Labor
Operation
4081088*

Description

Labor Time

Apply Lubricant to Exhaust
Valves

0.4 hr

*This is a unique Labor Operation for bulletin use only.

Version

4

Modified

Released on January 08, 2016
Revised January 22, 2016 – Added Corvette breakpoint, updated Additional Option
RPOS, updated step #2 and added step #3 to Correction.
Revised May 05, 2016 – Updated Additional Option RPOs.
Revised March 07, 2023 – Removed the Attention statement, updated Model Years,
removed Breakpoints, added Involved Region or Country section to table, removed
Export Regions, and Added Important statement under Correction.

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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