Have read all the threads on engine ticking. My 2004 LB7 has
more of a rattle. It is very noticeable at idle. It started at
about 400 miles. I now have 5200 miles on it & it is getting
louder. You can hear it in the cab at 70 mph on the freeway.
Dealer checked it at about 600 miles & at 1,500 miles & says it is normal. Normal my butt. Have to wear ear plugs before long to drive it. The parts guy at my dealership heard it & said it sounded like a lifter. When driving in the city, people on the sidewalks look at the truck like it is going to blow up.
Have listened to a lot of LB7's. None make this loud of a noise. Sounds more like a Cummins on steroids. Any of you Pro D'maxers have a clue what to look for? Thanks for any help anyone can give.

My best guess would be that the pilot injection isn't working. That's the pre injection system that is supose to make the diesel run quiet. I would assume if it is not working it would throw a code to alert the mechanics to fix something. Then again it could be an internal mechanical problem. If the dealership doesn't address the problem, get the district GM rep. involved. At least you want this problem well documented.
Good Luck,
Brad

blumax...when i bought my 2004 it only had 2000 miles and it sounded like what you are saying..after 40,000 miles ..chevy dicieted to replace the engine,mine did it at idle too.mine was more like a lifter tick than a rattle thu. take it to diffrent dealer,one that gives a s***ht.

Definently take it too a different dealer, call the ones in your area and ask if they have a Duramax/Diesel mechanic, I know it sounds funny but I found out that the Chevy Dealer I was taking mine too when I first bough it didn't. Before I moved from Juneau there was only a Duramax mechanic at the dealership on wednesdays because he traveled between the three chevy dealerships the owner owned around the state...my .02

Thanks guys for the info. Taking it into the dealer Monday to see
if they can finally find something. Had a mechanic that worked for a Chev dealer listen to it last night, he thinks injectors. Will
let everyone in on the good news next week.

Any chance you could post a recording of the sound? I'm thinking my '03 LB7 has gotten louder in the last 5k miles and even with a fresh oil change, sounds the same. The pilot injection system seems to kick in like it's supposed to, but the engine seems to rattle like a cummins (and it kinda comes and goes when I'm at idle in drive).

the tick is oil a cast mark in the block most noticed at 1500rpm's i have the bulletin from GM and will dig it out if you need the # so you can down load it to have for later reference or warrenty?