smoking exhaust

[gary goudeau]

I have a 2003 duramax with 97,000 miles on it. It has a sooty exhaust smell and smokes heavily when i accelerate hard in passing mode. Have truck at dealer for inspection and mech suspects #1 and #4 injectors could be bad when he performs injector bypass test. I also spoke with another diesel service tech and he sugested using the stanadyne fuel additive to see if that would solve my problem before spending money on injector replacement. Does anyone have any suggestions or experience with this problem?

[Shed]

I believe that your truck is under the 7yr. 200k mile injector warranty. Other more knowledgeable people here can verify, or ask the dealer. Read through here and you will find injectors are a common problem on the 01-03' LB7 engines. Mine were done at 65k. Any modifications to the truck? I know that GM is standing fast on warranty issues on trucks that have been modified in any way. Again there are people on here that will definately give you soild advice. Good luck! Shed

[gary goudeau]

Thanks for your reply shed. The dealer mech told me that GM is very picky on dirty fuel being the cause of my injector problem and may not cover the 7 yr., 200K warranty. Sounds like they are getting tired of replacing injectors for these engines. Always heard good things about the duramax engine. I'm beginning to think otherwise. Do the newer generation duramax engines have an improved injector design that is less problematic?
Maybe if GM would have teamed up with Cat we wouldn't be having these problem's. Never had injector problems with my Cat equipment.

[Shed]

I think that GM has improved the injectors in the newer versions of the DMAX. Seems like there are less posts about bad injectors from 04' on. Don't know about the cat engines, had an old firetruck with a cat, and she was a dog and always down for repairs. I've learned not judge by 1 bad expirience though. There is a ton of knowledge here hopefully someone can chime in with some advice. It seems as though dirty fuel is the biggest problem, I've heard some people not have any problems or atleast very few. The only difference I can see would be fuel quality. I'd push hard for GM to replace the injectors. The bulletin alson states that all 8 are to be replaced. Then maybe consider an auxillary fuel filter. Chime in boys, I've never heard you all so quiet!!! Good luck Gary. Shed

[Mark Rinker]

Your injector warranty is not an 'optional thing' for dealers. If you run into excuses, or resistance - get your truck to a new dealer that sees warranty work for what it is - guaranteed service department revenue.

I have a truck in today for my 4th set of warranty injectors, installed in three different trucks at three different dealerships. All have been installed cheerfully, professionally, and without a moment of hesitation.

[gary goudeau]

Thanks a lot guys for the feedback. Dealer says they are waiting to hear from the GM rep for approval. Dealer says that if GM tests the removed injectors and they don't meet thier specific requirements, they won't pay the dealer for a warranty claim. Service manager also said that if the injectors are replaced they use an upgraded version and the problem is solved for good.

Question: Does Bosch supply the injectors to GM? I was looking online for suppliers in case I will have to do it myself. What's your opinion on remamufactured injectors? Feedback is greatly appreciated.

[Mark Rinker]

Get to a new dealership. These guys aren't being honest with you. The 'injector test' is a bunch of bull****. As for the new injectors 'solving the problem for good' - ask him to put that in writing for you...

Injectors are simply a wearable part. They develop issues over time, and will be replaced a few times in the long life of a diesel engine. Period.

Do a burnout in their driveway, head for a better dealership with honesty and integrity at their core. Where do you live? There is probably a DP member that can make a recommendation for you...

[gary goudeau]

I'm going to take your advice Mark. I live in Napa California. Anyone know of a reputable GMC or Chev dealer within 50 miles of here? With an experienced Duramax tech.

I spoke to the mech at Kastner GMC here in Napa after I spent $180 for him to look at my 2003 GMC Duramax. He sounded a little unsure of the cause of my smoking exhaust. He was confident about the issue of GM not covering my vehicle because all of his tests passed inspection.

My feeling is that the injectors may be dirty due to bad fuel used by previous owners(2) if he is correct. What can I do to clean my injectors if this is the case?

[kaylabryn]

I would try and head towards the central valley as much as possible, a lot more farmers out there. With more farmers come more diesel trucks. Maybe southern or northern part of Sacramento.

Mike