Have an 06 LLY 2500 HD 4x4. It's starting getting colder in the mornings now and I have been noticing a ticking noise, not rythmic, but more random. I can hear it more prominently on the driver side. It only seems to do it at an idle and when I'm warming it up in the mornings... Any ideas??? I was thinking it may be a belt or something since it seems so random.

Search here on ' typewriter tick '. That is what it sounds like to me. If that sounds like your noise then it is common and does not hurt anything. Mine does from time to time. usually after a fresh oil change. But have not noticed this time since fill will amsoil oil.

Brian

I hope that's the case. It sorta sounds like it's just heating up or something. Hope everything is fine. Thanks for the comment

i would bet typewriter tick, my LBZ does it real bad. Learned to live with it.

Have an 06 LLY 2500 HD 4x4. It's starting getting colder in the mornings now and I have been noticing a ticking noise, not rythmic, but more random. I can hear it more prominently on the driver side. It only seems to do it at an idle and when I'm warming it up in the mornings... Any ideas??? I was thinking it may be a belt or something since it seems so random.

This is what the dealer gave me. And so far so goog.

#02-06-01-022G: Information on Engine Ticking Noise - (Jun 19, 2007)
http://gsi.xw.gm.com/image_en_us/gif/000/999/999/999999995.gif
Subject:Information on Engine Ticking Noise
Models:2001-2007 Chevrolet Silverado (Classic)

2003-2007 Chevrolet Kodiak C4500/C5500 Series

2006-2007 Chevrolet Express

2001-2007 GMC Sierra (Classic)

2003-2007 GMC TopKick C4500/C5500 Series

2006-2007 GMC Savana

with 6.6L Duramax™ Diesel Engine (VINs D, 1, 2, 6 -- RPOs LBZ, LB7, LLY, LMM)


This bulletin is being revised to add the 2007 Classic Pickup model. Please discard Corporate Bulletin Number 02-06-01-022F (Section 06 -- Engine/Propulsion System).

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)
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.