Duramax smoking badly

[Bill and Ann]

The truck has really started putting out black smoke when idling. Took it to the dealer and as there aren't any warning lights showing they say they are going to have to do a bunch of different tests to see if they can find out what is happening to cause the smoke.
At $100. per hour this should be interesting. The injectors have been changed at around 30,000 miles. Now have around 115,000.

[cmp-shooter]

Maybe you got bad fuel some where....try changeing your fuel filter 1st and look at the contents when pouring it out, might solve your problem cheep, esp if this just started also get a bottle of "Howes" AT A TRUCK STOP AND IF YOU DON'T USUALLY RUN ADDITIVE.. ADD 2OZ PER GAL OF FUEL IN YOUR TANK. To much howes won't hurt.All us truckers use it.

http://www.howeslube.com/products/index.php/category/20

[ARJ]

Air filter?

[RickW]

Is the black smoke only at an idle? Typically black smoke means too much fuel (unburnt fuel). It typically happens when the motor is under a load and the two most common causes are dirty air filter or bad injectors.

Also is your truck stock or do you have a programmer installed?

[HughM]

RickW is correct. Black smokes is unburnt fuel.
Hugh

[TLightning]

Black smoke normally means excess fuel or insufficient air.

[gitrdun]

That happened to my LLY and they flashed the computer and reloaded, fixed mine.

[Bill and Ann]

Both fuel and air filters have been changed recently. Also been using the Hughes. I also think it is fuel related. I hope it isn't the injectors again as I saw the bill the last time they were changed under warranty.

[Tom S.]

Actually I believe your injectors are covered under a 'hidden' warranty. GM has been covering injectors on the earlier models like yours for 200,000 miles. Ask your dealer - he should be aware of it,

[TLightning]

Here are some possible causes for black smoke: defective fuel injection pump, poor injector spray pattern, low injection opening pressure, clogged air intake, restricted exhaust system, or low compression pressure. At least that's what it says for my boat's diesel.

[Sinterior]

Bill and Ann, try going to dieselplace.com for info on any GM LT diesel engines, look under Duramax First Generation 2001-2004 LB7.
There are many actual Duramax techs there and other very knowledgeable people who know more than you would ever want to know about Dmax diesels.

I hope this helps

Peter

[Bill and Ann]

Thanks for the info. My appointment is on Wed. at the GM dealer. Will keep you posted on results.

[Bill and Ann]

Got the news. I have one bad injector that is spitting out diesel. The dealer says it is not a warranty item. Total cost for diagnosis and replacing the one injector will be just over $1500.
Picking it up today.
While at the dealer, got a good deal on a 2009 Malibu. So it was an expensive repair.

[Delaine and Lindy]

Bill sounds like your back in the Saddle again. The Malibu it a great car and excellent Gas mileage... I never seen deals on new cars like they are today. But we are kinda looking for a used (Preowned) pick-up to pull the small utiliy trailer, not many good deals on used Trucks here in TN. Must have 4 doors, oue dog "Montana" requires his own windows and space. GBY....

[Tom S.]

Have the dealer check again. Your truck has an extended warranty on the injectors that covers them for 200,000 miles or 7 years from the date the truck was put in service. Since your truck is a 03, I don't know if it's under the 7 years or not. GM dealer Bulletin covering this can be found here: http://www.duramaxforum.com/forum/240744-post45.html

[SlickWillie]

Tom is correct on the warranty. Injector warranty on the LB7 Duramax was extended after all the issues with the injectors. I have a friend back in East TX that had his replaced under warranty on his 2003 Chevy, and my son received a letter from GM extending the injector (nothing else)warranty on his 2004 LB7 engine. My 2004 GMC is the LLY engine, and only carries the 5 year 100,000 mile warranty. If the dealer does not come through, I would be contacting someone higher up with GM.

[Mudchief]

They just replaced all the ones in my son's 03 under that bulletin. However some dealers will try to bill you rather than GM because GM will pay them less than they can get from you.

[dsprik]

All above are correct. It should be a warranty item, Bill. My 2002 LB7 Duramax had the injectors replaced at 122,175 miles - under warranty. Your injectors put in at 30,000 miles were unlikely the new re-designed injectors that everyone had put in under the 200K warranty. If replaced by a dealer, those 30K injector will show up on GM's computers. It will tell you if these are the new injectors.

[Montana Sky]

The LB7 does qualify for the 200k injector extended coverage; however, there are stipulations. It is not an all or nothing extension.

[Bill and Ann]

I had the bulletin that was posted on Diesel Place in my hand, but the injector failure that occurred was not covered as Dave mentioned above. Oh, one more thing, the Service Manager and the Diesel mechanic both told me that under no circumstances use any type of additive with the Duramax as it damages the injectors. I am not going to get into the pros or cons of that statement as it was been well discussed in other forum posts. Just passing info along.
Delaine and Lindy: I was hoping you would show up at Two Rivers Campground, like last time we were there. We had a blast for the week we were there for the Music Fest.