Black fuel filter(pics included)

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

  1. God prefers Diesels

    God prefers Diesels Road Train Member

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    Kind of. A leaking injector means it's dumping fuel when it's not supposed to, and washes the cylinder wall.

    In this case, it's not sealing at the seat, so when combustion occurs, some exhaust pushes past the injector, and up where it doesn't belong. So soot can get in your fuel (depending on injector style) and in your oil (because it goes right past the injector into the valve cover, and now it's in the crank case).

    You seeing more vapor than usual out your blowby tube?
     
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  3. nikmirbre

    nikmirbre Road Train Member

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    Now that I couldn't tell you, I can say the few times ive paid attention the answer is no but, I don't know for sure.
     
  4. nikmirbre

    nikmirbre Road Train Member

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    Forgot to add this.....My boost pressure reaches about 48-50 on a hard pull or full throttle. The boost pressure sensor throws an engine code after about 42-43. It smokes a bit going through the gears especially when heavy. Don't know if that has anything to do with it......
     
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  5. jason6541

    jason6541 Road Train Member

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    Sounds like a bad wastegate or someone has some fancy program in ect and turned up. Black smoke is just unburned fuel. Yeah I believe it’s s but much for boost
     
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  6. DDoubleDD

    DDoubleDD Bobtail Member

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    I'd check the wastegate actuator for free movement. If good then see if it's being controlled. If no joy then on to the injectors. Maybe whatever is going on in your fuel tanks is the cause of injector problems.
     
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  7. Bakerman

    Bakerman Road Train Member

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    FEC9A6F8-44D3-4E9E-A40E-9F2830EC6839.jpeg
    i’ve had the same problem and have used this product with success
     
  8. Big Road Skateboard

    Big Road Skateboard Road Train Member

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    It could be algae, but not likely. Most likely combustion chamber gasses.

    Most people assume it's from injector o rings, but actually it gets into the fuel through an injector tip that's not completely sealing off.

    A fuel analysis can tell you for certain. Unfortunately, if it's gasses, there's no way to determine which injector.
     
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  9. nikmirbre

    nikmirbre Road Train Member

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    Yeah none of local places had any.......I had to order some from amazon it'll be here tomorrow
     
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  10. Rideandrepair

    Rideandrepair Road Train Member

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    I just bought 4 bottles at Wal mart. My Tanks are black inside. Been using that stuff and different bio cides for a while. No change yet. No slime yet. Even let it soak for a week with full tanks. Gonna try again. Had a bad injector, a while back, ran it a while that way. Might be from combustion gases. I still don’t know myself. Have had algae before. Couple tanks of bio cide clears it right up. Black slime looks like silicone. Can’t miss it. Floats on top of my spin on filters when I change them. Need a supply of filters. Really just primary in my case anyway. You must have a Davco? I’d think you’d see slime in it easily. Might be wrong.12.7 has copper cups. Over time the pounding of injector distorts the seat. A graphite crush washer is the easy fix. Along with a big fat O ring top washer, for the oil. O ring kits come with both, along with the 3 regular o rings for fuel supply and return valleys. They’re about $25 each at Dealer. Online much cheaper. Look them up, you’ll see. Originally the top O rings aren’t as big, and no washer for seat. The graphite washers are considered band aid repairs by some Mechanics. Others use them anytime they change injectors. Won’t hurt to use them. I prefer to. The graphite’s so soft, they crush down, and don’t even add any height to the injector. You could crush them with your fingernail. As far as fresh black oil, happens quite a bit. I’ve heard a lot of complaints about Detroit’s doing that. Mine does. When I change it myself, I let it drain a long time. Must be the angle I’m parked on? I get a better drain, oils not as black, but very soon turns black again. The design of the pan leaves some oil in the bottom. I’m going from 20k back to 15k Per Detroit’s Original recommendations. Since I’ve done an inframe. I’ve already pushed it to 22k last time. Only have 51k on inframe. Been idling a lot. See a bit of blow by or steam already sometimes. Usually in high humidity weather. It’s the 12.7 plague. Going to do a couple 10k oil changes. Had a bunch of sludge, due to excessive Lucas before inframe. Whatever the cause. Won’t hurt the engine. Can’t kill them!! I tried. Lol.
     
    Last edited: Aug 10, 2021
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  11. Rideandrepair

    Rideandrepair Road Train Member

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    Let Us know if you figure it out. I hear about asphaltene. Like a thick asphalt coating on tanks. Hard to get rid of. Caused by injectors leaking or ?combustion gases. They have additives for that. But Ive read that’s usually a new emission Truck problem. That’s my next move.
     
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