2004.5 LLY at idle (most noticable) it ticks out the passenger side like a manifold leak. No tracks of soot anywhere I can see. Truck has about 2000 miles and runs great. I would have expected to find something down stream of the turbo. Gets better when hot. Hope it is not the head or an injector! Have a Predator and have tried every level. Still runs good but has that annoying noise! Back at stock program and about to take it to the dealer. Work on mechanical diesels all the time but these electronic machines are beyond me!-(

Do you hear it at idle or is it when you accelerate?

Same here I have a small ticking noise from the engine compartment at idle??

Any Ideas?

same here-

same here-
Me too. Must be normal...........

Every LLY that I know of has a ticking noise. Dealers say it is normal. Only difference is that I have always been able to hear it more on the drivers side.:confused:

I noticed my GMC doing it tonight. Mine sounds like something is on the belt and slapping every time it makes a loop. I have 1800 miles. Mine is noticable on both sides. Strange thing the 2005 chevy with the same engine does not do it and it idles a lot 4500 miles and 300 hours. Truck does get ran hard with a load all the time, maby that is the diff.

Totally normal, Mine had it until about 11,000 miles. It is less noticeable now. I heard mine on the drivers side as well. FAGEDABOUTIT ;-) do a search on ticking and you should find other posts regarding this issue. Good luck

Tried it tonight on stock tune. The tick is more noticable at idle, not during accelleration, less when hot. On stock tune find more noticable turbo wine which blows away any other sounds during accelleration. Also tried the old gloved hand over the exhaust pipe, boy what pressure! Could probably explode the muffler doing this but did not hear or feel any exhaust leaks. Should have had someone up at the engine listening. Will retry the tuner and see if I can retrieve any data on cylinder balance etc.

my truck has the same noise on drivers side

"This bulletin is being revised to update the models information. Please discard Corporate Bulletin Number 02-06-01-022 (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(TM) 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(TM) 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."

The above bulletin concerns LB7s. My LLY ticks too. I don't sweat it---it's normal.

Go here for more discussion:http://dieselplace.com/forum/showthread.php?t=142

Its funny that this is more noticable due to the reduction in combustion noise usually assocated with diesels. Using the Predator at the settings that eliminates the two stage injection one usually does not hear it. That of course is due to the extreme combustion noise one gets above idle. It seems these are so quiet at idle the internal harmonics etc are more noticable. Seeing the above note I am going back to the higher setting as the throttle response is significantly better. Would have seen a bit better fuel mileage if I can keep my foot out of it!-) I work with most engines built all over the world. The ISM Perkins (japanese) is a very low combustion noise engine. I had not heard any ticking noises out of those but they are all 2-4 cyl 0.5-2L diesels. All the others sound like the usual bucket of bolts. The V8 configuration is not the usual diesel we see (or hear) and this may contribute to this phenomena. Thanks for the feedback.

2004.5 LLY Silverado 4x4, 2001 Dodge W3500 4x4 Cummins 6BTA (nasty sounding thing!)

Well I feel a little better knowing that i'm not the only one. My Truck only has 700 miles on it and I noticed it last week.

I noticed mine ticking at around 5500 mi. Took it to the dealer and they gave me 3 or 4 service bulletins and said it was normal. My engine use to idle real quiet, not no more. Mine also comes from the passenger side. I hate it, wish there was a fix............Rick

I have about 25k on mine , tick is either less noticable or I've grown accustomed to it. Pretty sure it's not a problem.

We complained about this ticking noise about 1 month after delivery. Took it to the dealer and the service manager gave us the following document:

INFORMATION ON ENGINE TICKING # 02-06-01-022C
DATED - 1/26/04

It States:
The 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 metalic ticking noise. The noise could be described as an irregular ticking or clanking sound, like random typing on a mechanical typewriter.
The truck now has 22,000 miles and the noise is alot less noticeable.

LT Construction Co.
2004 Chevrolet
D/A
Ext Cab-LT

My truck "ticks" if I use Shell Rotella dino. It does not "tick" if I use Shell Rotella synthetic. Have not tried other oils. The tick was there when I bought the truck. Tick went away with change to synthetic (two oil changes). Yesterday I put in the dino and the tick is back. Truck seems to be just a little bit louder at idle. Plan to go back to Rotella synthetic at the next change to get more data. Coincidence?