Bulletin No.:

Service Bulletin

Date:

17-NA-304
February, 2020

TECHNICAL
Subject:

Brand:

Cadillac

Chevrolet

GMC

Ticking, Rattle and/or Buzzing Noise Heard from inside Passenger Compartment,
Possible Fuel Leak

Model:

Model Year:
from

VIN:
to

from

Engine:
to

Escalade

L86

Escalade
ESV

L86

Suburban
Tahoe

Transmission:

L83
2015

2020

L83

Yukon
Models

L83, L86

Yukon XL
Models

L83, L86

Involved Region or Country

North America, Middle East, Europe, Russia, Chile, Columbia, Ecuador and Peru.
Some customers may comment on the following condition:
• A rattling and/or ticking noise that may be louder inside the vehicle than outside.

Condition 1

⇒ The noise may be picked up at the back of the left valve cover, and/or
underneath the vehicle near middle of the driver’s door.
⇒ This noise will be noticeable at idle, most noticeable in the 700-900 RPM
range.
⇒ The noise may also sound like a lifter tick.
⇒ This may also be called a fuel line buzz or ringing noise.
• While the rattle is occurring, the S-shape portion of the fuel feed line, right in front of
the tank, will be vibrating / rattling.

Condition 2

Some customers may comment on a fuel leak.
Diagnosis that the fuel leak is originating from the fuel feed line at the molded-in clip on
top of tank.

Cause

The rattling, ticking noise may be caused by the check valve in the low pressure fuel feed
jumper line at the engine not fully seating, allowing pressure pulses from the high
pressure side back into the low pressure side of the fuel system.
These pressure pulses could cause the S-shaped portion of the fuel feed line, in front of
the tank, to vibrate and/or rattle
If the S-shaped portion of the fuel line rattles over a period of time, the fore-aft motion in
the line could result in wear. This wear could result in a fuel leak where the line is secured
into the molded-in clip on the tank.

Copyright 2020 General Motors LLC. All Rights Reserved.

Page 2

February, 2020

Bulletin No.: 17-NA-304

4863652

1. Using a stethoscope or equivalent, engine running, listen to the low pressure fuel
pipe connection (1) at the left side of the engine (2). (Will be very loud in
stethoscope while issue is occurring.)
Correction 1

4863631

2. Engine running, inspect the low pressure fuel pipe S-shaped portion (1) in front of
the fuel tank for vibration / rattle.
• If the vibration / rattle condition is present, then the low pressure fuel feed
jumper pipe at the engine will need to be replaced and the fuel feed pipe at the
tank will need to be replaced with the updated design.

Bulletin No.: 17-NA-304

February, 2020

Page 3

Correction 2

4863689

1. Inspect to determine whether the fuel leak is originating from the fuel feed pipe
where it is retained into the molded-in clip (1) on top of the fuel tank.
• If the fuel leak is originating from the molded-in clip area of the fuel feed line,
then the low pressure fuel feed jumper pipe at the engine will need to be
replaced and the fuel feed pipe at the tank will need to be replaced with the
updated design.

Service Procedure
Install a new low pressure fuel feed jumper line at the
engine, and replace the original design fuel feed line at
the tank with the appropriate updated design PN listed
in the Parts table, following the procedure below.

Page 4

February, 2020

Bulletin No.: 17-NA-304

4863828

Low pressure fuel feed jumper pipe at engine

Original design fuel feed line at tank

4870639

4863840

Updated design fuel feed line at tank
Note: Summarized below are key notes for both the
low pressure fuel feed jumper pipe at the engine and
the low pressure chassis fuel feed pipe at the tank.
Refer to Fuel Feed Pipe Replacement (At Engine) and
Fuel Feed Pipe Replacement (At Tank) for complete
procedures.

Bulletin No.: 17-NA-304

February, 2020

Page 5

4864094

1. Replace the low pressure fuel feed jumper pipe (1)
at the engine.
2. Lower the fuel tank assembly and remove from the
vehicle.
3. Remove the low pressure chassis fuel feed pipe
from the fuel tank.
Note: Provide protection for the fuel feed port on the
fuel pump module.

4. Using shop air, clean the fuel feed pipe run
channel on the tank to remove dirt and debris.

4863840

5. Position the updated design fuel feed pipe to the
fuel tank and make connection to the fuel pump
module.

4863833

Page 6

February, 2020

Bulletin No.: 17-NA-304

Parts Information
Causal
Part

Description

Part
Number

Qty

x

Pipe Asm-Fuel
Feed (Jumper at
Engine)

12618338

1

x

Hose Asm-Fuel
Feed (at Tank)
(Updated
Design, SWB)

84200271

1

x

Hose Asm-Fuel
Feed (at Tank)
(Updated
Design, LWB)

84200274

1

Warranty Information
4864117

6. Install the fuel line into the tank molded-in clip and
ensure the line is fully seated.
7. Install the fuel tank to the vehicle.
8. Validate the vibration / rattle in the fuel line has
been eliminated.

For vehicles repaired under the Emission coverage,
use the following labor operation. Reference the
Applicable Warranties section of Investigate Vehicle
History (IVH) for coverage information.
Labor
Operation
4081878*

Description

Labor Time

Fuel Feed Pipe
Replacement at Engine
and Tank

2.7 hrs

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

Version

3

Modified

Released September 22, 2017
Revised August 08, 2018 - Added 2018 and 2019 Model Year and removed cutoff dates.
Revised February 03, 2020 - Added 2020 to Model Year.

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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