Black fuel filter(pics included)

Discussion in 'Heavy Duty Diesel Truck Mechanics Forum' started by nikmirbre, Aug 9, 2021.

  1. Big Road Skateboard

    Big Road Skateboard Road Train Member

    4,684
    22,368
    May 2, 2021
    0
    If you'd have done the fuel analysis, you'd have gotten the results already. No guesswork involved, and takes seconds.

    Still betting on combustion chamber gasses. Seen it many times. Oil cannot get into your fuel through injector o rings or cups, and while it's possible the fuel pump could, never seen it in 27 years of Detroit work.
     
    jason6541, nikmirbre and Rideandrepair Thank this.
  2. Truckers Report Jobs

    Trucking Jobs in 30 seconds

    Every month 400 people find a job with the help of TruckersReport.

  3. nikmirbre

    nikmirbre Road Train Member

    5,104
    8,828
    Jul 27, 2011
    High Point NC
    0
    Youre probably right
     
    Rideandrepair Thanks this.
  4. nikmirbre

    nikmirbre Road Train Member

    5,104
    8,828
    Jul 27, 2011
    High Point NC
    0
    Combustion chamber gases= are you saying worn piston rings?
     
    Rideandrepair Thanks this.
  5. bad-luck

    bad-luck Road Train Member

    3,070
    5,531
    Nov 16, 2013
    Baltimore, Maryland
    0
    Looks like oil in your fuel. Check you fuel tanks to see if they are discolored.
     
    Rideandrepair Thanks this.
  6. nikmirbre

    nikmirbre Road Train Member

    5,104
    8,828
    Jul 27, 2011
    High Point NC
    0

    Its a 12.7 there is virtually no place for that to happen. Tanks are clear and clean!
     
    Rideandrepair Thanks this.
  7. Big Road Skateboard

    Big Road Skateboard Road Train Member

    4,684
    22,368
    May 2, 2021
    0
    No. It is almost always minute amounts of gas getting into an injector from one of the injector tips not sealing off completely.

    Unlike a loose injector or bad injector o rings, where the amount of gasses affect driveability, the small amount getting into the fuel through a tip is rarely noticed until the fuel darkens.

    Don't just throw 2k into a set of injectors though. Do the fuel analysis first to verify the reason it's dark.
     
    nikmirbre and Rideandrepair Thank this.
  8. nikmirbre

    nikmirbre Road Train Member

    5,104
    8,828
    Jul 27, 2011
    High Point NC
    0
    Ok yes I was gonna say I don't exhibit any of the other symptoms of worn rings at all. Ive ordered a fuel test kit already from blackwater labs I think is the name of it....
     
  9. bad-luck

    bad-luck Road Train Member

    3,070
    5,531
    Nov 16, 2013
    Baltimore, Maryland
    0
    I never heard that it can't happen to a 12.7. It can happen to any diesel engine through the return fuel line to the tanks. It looks like oil to me, its possible you got bad fuel somewhere. I recommend you get your fuel analysis done, before you proceed any further.
     
    nikmirbre and Rideandrepair Thank this.
  10. nikmirbre

    nikmirbre Road Train Member

    5,104
    8,828
    Jul 27, 2011
    High Point NC
    0
    Ill take a picture of the fuel when I dump some out of the fuel filter.

    On a 12.7 there is no oil rail feeding the injectors. And there is a 1/2 inch gap between the fuel pump and air compressor with a spill port to the outside. Oil in fuel on a 12.7 just doesn't happen.

    The fuel looks like little bits of black soot(which I actually thought soot was thin and would dissolve) when I pour in a bottle.

    Ill take a picture either tonight or the morning..probably the morning lol
     
    Rideandrepair Thanks this.
  11. Rideandrepair

    Rideandrepair Road Train Member

    16,643
    54,395
    Aug 8, 2015
    0
    I had the black fuel and pieces of fuel lines. Replaced the lines from tank to GT return valve. They were probably 15 yrs.old.
     
    nikmirbre Thanks this.
  • Truckers Report Jobs

    Trucking Jobs in 30 seconds

    Every month 400 people find a job with the help of TruckersReport.