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Thread: Are my LB7's injectors leaking?

  1. #1

    Default Are my LB7's injectors leaking?

    Hi! I'm new here but have poked around in the forums for quite awhile. My 2003 LB7 has light grayish-white smoke at idle and a puff of the same color when I start from a stop. It seems to be worse if the truck idles longer or if I decelerate slowly from cruising speed to a stop without much use of the brakes. The fuel filter is new, the air Cleaner is not restricted, and I recently cleaned the MAF sensor. I usually run a fuel additive (amsoil).The truck has 104,000 miles on it but I've only had it for the last 27K so I'm not sure of it's injector history. Reading other posts it sounds as if my injectors might be going bad? If so is the condition that usually causes this color smoke covered by the 200K injector warranty or not? My apologies if this is a rehash of existing posts. I do have a Banks Stinger system that I run on the economy setting if it makes any difference.
    Thanks

  2. #2
    Join Date
    Apr 2001
    Location
    CA
    Posts
    13,573

    Arrow

    Welcome aboard!

    Sounds like injectors. They will be covered under warranty, if you can duplicate the condition without the Stinger hooked up. DO NOT, under any condition, show up at the dealer with the Stinger in sight! Leave it at home. Check your oil level, and keep a close eye on it.
    1985 Blazer 6.2
    2001 GMC 2500HD D/A
    dmaxmaverick@thedieselpage.com

  3. #3

    Default

    Try adding a quart of ATF every tank of fuel and see if the smoking clears up. I have been doing this with my 2002, and for some reason, it seems to be keeping it at bay.

    My truck has 3 or 4 injectors slightly out of range. If you get 1 or 2 way out of range, you'll know it. Fuel knock, oil dilution, mosquito-fogger type exhaust smoke, etc. will most likely follow.

    Since your coverage goes out to 200K or 7 years in-service, you should try to get as many miles out of this set as possible, IMO.
    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

  4. #4

    Default

    Thanks. The smoke every time you pull away from a stop sign is irritating as well as the smell but perhaps I'll wait till it gets a little worse. I'd hate taking it in and having them tell me that (at least while they had it) it was not bad enough to be covered by warranty--and then have to pay the $150 testing fee.

  5. #5

    Default

    You can have it checked anywhere with a Tech-II scantool. The injector balance rates are the key indicator. As I mentioned before, if you have 2 or 3 slightly out of range, the LB7 can smoke at idle for a long time before you get to real issues.

    If you are seeing clouds of white, stinky exhaust, its time for replacement. Sounds like you might be there...
    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

  6. #6

    Thumbs up fixed!

    I took the truck to the dealer about two weeks ago and explained the symptoms. The service writer said it sounded like injectors and they'd replace them if so. All eight replaced, $0, and the truck runs better than it has since I bought it--a lot quieter.

  7. #7
    Join Date
    Mar 2007
    Location
    Pacific Northwest
    Posts
    740

    Arrow

    What dealer did you take it too? Where are you located? Pacific Northwest?
    1998 Chevy k-2500 454 147,000 miles and climbing!

    1993 Pontiac G/A Big Block 3.3 Liter 140,000 miles and still going too!

  8. #8

    Default

    I'm in the central valley in California. The dealer was Chase in Stockton.

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