My 2004 Silverado with 6.6 turbo diesel LLY, smokes black smoke mainly on acceleration. This problem occurs either with or without a load. I have had the truck to 2 different dealers, both concluded that fuel was the culprit. They stated no codes were present. I have since ran through a full tank and the problem has resurfaced. Are additives the answer to better lubricate the injectors? I am currently having a sample of fuel taken to be analized by one of the dealers. I will advise further. Thanks for your comments. No more bugs alive in Indiana.

Do you have any mods done on the truck?

Define "black smoke".

If you can still see the car behind you, you are OK.

If you can't see the car behind, make sure it wasn't a cop.

Do you have any mods done on the truck? No, this truck is stock with about 3,500 miles on it. Thanks for the reply.

Define "black smoke".

If you can still see the car behind you, you are OK.

If you can't see the car behind, make sure it wasn't a cop.So bad that vehicles were changing lanes and/or slowing just to find oxygen.

is it like foot-to-the-floor acceleration?

is it like foot-to-the-floor acceleration?No, had a dealer tech with me and he could not believe the smoke. This is a very intermittent problem, not on every ecceleration. It occurs while towing and/or normal driving.

I had the same problem...dealer found a bad injector. Also had the low speed surge. After a new injector and reflash nos moke..picked up almost 2MPG.

My LLY started doing this at about 4250 miles.:mad: Got the reflash which fixed the rough idle at a stop/parking lot surge, but not the smoke. Took it back in and asked for a full Tech II analysis to include injector balance rates. One injector was intermittently bad and GM approved new injector(s). Since my injectors were on backorder during the period that the GM restrictions went into effect, I had to take it in for more testing. This time the injectors were working great, almost perfectly balanced, so they did nothing other than place my customer concern on file. After research on this forum, I had already decided to start putting in Stanadyne Performance Formula All Season Diesel Fuel Conditioner. I proposed this to the diesel shop manager and he concurred with using it since it is the only one approved by GM (his words). Bottom line: in less than a quarter of a tank, the truck is running better, the smoke is now minimal under hard acceleration, and it feels like it did prior to my problems starting. I don't like having to put an additive in my fuel, but until they solve whatever's going on with the injectors, that's what I'm going to do. The diesel shop manager said he expects something to come out of all the LLY injector problems since GM and Bosch are working hard to find out what is causing the problems. IMO it's the low sulfur fuel we're getting. Any other ideas?:confused:
http://www.stanadyne.com/new/ppt/showfile.asp?id=1295

Try some STANADYNE!!!!!

that Stanadyne addative workes great i have used it since i got the my truck. i got 18000 miles on it now and the only time i have problems (rough idle, surging, smoking) is when i don't use it. The tech i know at chevy said to use it all the time. I have been useing it on every tank since then and he is right you notice a difference.

I am now driving a new 05 that GM replaced since my 04 was doing the same as yours!!!!

To get mine to smoke:
Drive on the freeway first thing without more than 15 mins of warmup time.
It sometimes took another 15 mins of freeway driving and the smoking and knocking started.

To get it to stop:
Pull over, let it idle for 5 mins, sometimes shut it off and restart and I was good to go. After that I could drive it all day and night without ever knowing anything was wrong. The dealer didn't have any problems making it smoke and rattle and knew it was the #8 injector doing it but after replacing it and all the computers it still didn't fix the problem.

I have never believed it was a fuel problem and refused to add Stanadyne to mask a problem. Most of these engines run fine without it and I know a few guys that get their fuel at the same place as I do without problems.

The new 05 with 700 miles is running like a top!!

Dennis

:ro) Here's my story, I have a 05 chevy 2500HD CC LWB w/ duramax set up. It ran great no smoke till this week. At 2500 mile i'm getting black smoke on acceleration, the harder I push it the more smoke. Now here's my question could the air cleaner's starting to plug cause this to start? What do you guys think. I'm going to change mine out tomorrow and see what happens. My grandfather always said try the easy stuff first, or KISS keep it simple st--pit ):h
PS no mods on this truck, Nictane pre fuel filter, 409 fuel treatment and we live in western Penna.

Here's the rest of my story, got the new air filter ( napa gold ) this morning in between stops, put it in right there on the spot. started off to the next stop and no black smoke on aceleration :D . the old filter had 2500 mile on it and the surface was dirty ( black soot ), but in between the pleats was clean. ( it was the original AC ). Has anyone else had this happen? Diesels are new to me so i'm trying to learn. if this filter had been on one of my gassers it would of been good for 15K more? I love this truck so no problem here changing filters at 2500 mile interums :ro)