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Thread: Exhaust question

  1. #1
    Join Date
    Jan 2005
    Posts
    19

    Default Exhaust question

    My 2002 HD 2500 Duramax has started smoking a lot and the exhaust smells rich like it is unburned diesel. It isn't using any oil. Can someone give me an idea what may be causing this problem?
    thanks for any help.
    Jack

  2. #2

    Default

    Welcome to the board.

    You are describing classic symptoms of an injector 'hanging up', or not spraying fuel properly.

    You should have it analyzed by a dealership ASAP - the problem won't likely correct itself, and continuing to run the truck until it gets worse and worse can do damage to the piston and/or valves of the offending cylinder(s) if left unrepaired. The next thing that will likely happen is the oil level rising, due to dilution from excess fuel making its way past the rings and mixing with crankcase oil. In layman's terms - that is 'bad'.

    Search the Duramax forum - where I am moving this post - for more information on this common malady. Hopefully you have under 200K miles on your truck, you will probably get a new FREE set of 8 injectors. Don't let the dealership replace individual injectors if that is suggested.

    If they are following the GM warranty program, you'll get all 8 on an LB7 (2002 engine) without having to ask.
    2011 Chevrolet Tahoe 5.3L daily driver
    • Previous owner of two 1994 6.5L K3500s, '01, '02, and '05 6.6L K2500s, '04 C4500, '06 K3500 dually, '06 K3500 SRW, '09 K3500HD SRW, '05 Denali
    • Total GM diesel miles to date : ~950K

  3. #3
    NutNbutGMC Guest

    Default

    Quote Originally Posted by JackRH View Post
    My 2002 HD 2500 Duramax has started smoking a lot and the exhaust smells rich like it is unburned diesel. It isn't using any oil. Can someone give me an idea what may be causing this problem?
    thanks for any help.
    Jack
    Read up here on the fuel injectors for the LB7 engine. It's a common and inherent problem. I agree with Mark.

  4. #4
    Join Date
    Jan 2005
    Posts
    19

    Default

    Many thanks for the help. Took my truck to a dealer and was told the injectors would fall under warranty but the flow rate,???, was low so that voided the warranty. Took the truck to another dealer and they changed all injectors under warranty, no charge. Feel like I just hit the lottery since the first dealer wanted almost $5000 to repair the injectors.
    Don't want to look a gift horse in the mouth but had just changed my oil and filter (Amsoil) and they replaced it with regular oil. not a bad exchange for $5K.

    Now tell me about adding oil and diesel additve to my fuel when I fill up. A buddy tells me I should put in a quart of 2 cycle oil plus some of the diesel fuel additive. Is this good advice? what do most people do?
    Again thanks for the help and sorry to be long winded and short on mechanical skill.
    Knapper

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