File in Section:

Service Bulletin

Bulletin No.:
Date:

06 - Engine
02-06-01-022O
September, 2014

INFORMATION
Subject:

Information on Diesel Engine Ticking Noise

Models:

2001-2015 Chevrolet Silverado
2003-2009 Chevrolet Kodiak C4500/C5500 Series
2006-2015 Chevrolet Express Vans
2001-2015 GMC Sierra
2003-2009 GMC TopKick C4500/C5500 Series
2006-2015 GMC Savana Vans
Equipped with Duramax™ Diesel Engine (RPOs LBZ, LB7, LGH, LLY, LML, LMM)
Please Refer to GWM/IVH
This bulletin has been revised to add the 2014-2015 Model Years. Please discard
Corporate Bulletin Number 02-06-01-022N.

Some of the above vehicles may exhibit a random ticking noise that is most audible on an engine with a coolant
temperature of 70°C (158°F) or higher and from idle to approximately 1500♦RPM. The noise usually is most
noticeable at the rear of the driver's side front wheel well. Customers may also comment about hearing a tick noise
inside the vehicle at idle such as when sitting at a drive through window. All 6600 Duramax™ diesel engines have
this condition; however, some are more audible than others. Engine build variation from engine to engine contributes
to differences in perceived volume. All Duramax™ engines are manufactured to very close tolerances to meet the
durability and reliability standards.
This noise is caused by the relationship of the engine cylinder block, crankshaft journals, bearing inserts and the oil
film. This relationship may allow a vibration that resonates through the cylinder block and is heard as a metallic
ticking noise. The noise could be described as an irregular ticking or clacking sound, like random typing on a
mechanical typewriter.
This condition has been present in diesel engines produced for the last 20 or more years. The overall noise
reduction in engines produced today makes this noise seem new when, in fact, it was masked by other noises in the
past. Many manufacturers such as Isuzu, Hino, Mitsubishi, and Nissan report a similar condition in their diesel
engines. Testing and engine teardowns with this condition reveal no condition that would affect reliability or durability
of this engine.
Dealers should not attempt to compare any customer vehicles exhibiting this noise with other similar vehicles as the
noise is different from vehicle to vehicle and this may lead to the incorrect conclusion that the vehicle has a
condition. This noise is a normal operating characteristic of the engine. This noise has no short or long term effects
on the engine. Do not attempt repairs for this noise.
Important: Replacing the engine or internal components for this noise will not reduce or eliminate the noise.
Please share the information found in this bulletin with customers who inquire about this condition. In the event they
have additional questions or concerns, please advise them to contact Customer Assistance at the numbers listed
below for further information.

Division

Number

Deaf, Hearing
Impaired or
Speech
Impaired*

Chevrolet

1-800-222-1020
8:00 AM - 11:00
PM (EST)

1-800-833-2438
8:00 AM - 11:00
PM (EST)

GMC

1-800-462-8782
8:00 AM - 11:00
PM (EST)

1-800-462-8583
8:00 AM - 11:00
PM (EST)

Canada

1-800-263-3777
(English)
1-800-263-7854
(French)
7:30 AM - 11:30
PM (EST)
(Mon-Fri)
7:30 AM - 6:00
PM (EST) (Sat)

1-800-263-3830
7:30 AM - 11:30
PM (EST)
(Mon-Fri)
7:30 AM - 6:00
PM (EST) (Sat)

*Utilizes Telecommunication Devices for the Deaf/Text
Telephones (TDD/TTY)