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if the 6.2 is a knockin', don't bother rockin'...

Discussion in '1982-Present GM Diesel' started by DieselBurb, Aug 19, 2003.

  1. DieselBurb

    DieselBurb 1/2 ton status

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    if the 6.2 is a knockin\', don\'t bother rockin\'...

    I just replaced the head gasket on my 85 6.2 and after getting it going again, it has a knock that I don't remember it having before. It doesn't sound like a lifter, so I thought maybe it's a rod talking. I have good oil pressure, so that rules out con rod bearing, right? It knocks under acceleration, but no during decelleration.

    Any ideas?
     
  2. arveetek

    arveetek 1/2 ton status

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    Re: if the 6.2 is a knockin\', don\'t bother rockin\'...

    Could be an injector. When an injector goes bad, they can cause a knocking by squirting the fuel wrong or dribbling the fuel.

    Here's how to check for a bad injector: with the engine running, loosen one injection line, see if the knock goes away. If it doesn't, tighten that injection line down, move on to the next one in line. Do this for both sides of the engine. If loosening one of the injection lines does make the knock goe away, try swapping the injector with one on the opposite bank. If the noise follows the injector over to the other side of the engine, then you've found your problem.

    A rebuilt injector from my local Standayne diesel shop costs me about $24.95.

    Casey
     
  3. DieselBurb

    DieselBurb 1/2 ton status

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    Re: if the 6.2 is a knockin\', don\'t bother rockin\'...

    Casey, thanks for the info. I think I have an injection line that is leaking which might be causing the problem with the injector. If the injector is in fact the problem, will it hurt it to drive it with the knock?
     
  4. arveetek

    arveetek 1/2 ton status

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    Re: if the 6.2 is a knockin\', don\'t bother rockin\'...

    If it is an injector, it's not good to run it for very long. If it's dripping fuel, it could burn a hole into the piston.

    Casey
     
  5. ZZ4x4

    ZZ4x4 1/2 ton status

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    Re: if the 6.2 is a knockin\', don\'t bother rockin\'...

    I had the same problem (major knock), and it definitely was a bad injector. I had the signs of a leaking fuel line (bubbles when I cracked the fuel line at the injector). Turns out the piston was pushing air back through the injector. A rebuilt one for $14.95 solved the problem. /forums/images/graemlins/smirk.gif
    Good luck.
    Jeff /forums/images/graemlins/usaflag.gif
     

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