X15 Exhaust smoke while climbing a steep grade

Discussion in 'Heavy Duty Diesel Truck Mechanics Forum' started by Josiah Harder, Apr 23, 2023.

  1. Josiah Harder

    Josiah Harder Light Load Member

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    I'm in Montana climbing a grade and I notice heavy smoke coming from the stacks. It seems white but looked dark at times when really thick and also blue as it dispersed behind me so hard to tell what color it really is but mostly white I'd say. I took a quick video that I'll attach. I pulled over 10 miles after noticing this but it seemed to only be smoking when I would be pulling a grade. Even a small grade but when I was going flat or down I could be at full throttle and not notice any smoke. After 10 miles I could smell something burning and it smelled like my DPF. The smoke seemed to go away at times I would be at full throttle and not see anything but then I would be at half throttle and see it billowing out. When I parked my truck it
    went into passive Regen for a little bit and I could see puffs of smoke leaking from the dpf can somewhere but there was no smoke coming out the stacks. I sat for 45 minutes looking up shops and found one 4 minutes away so I drove there and gave it full throttle through my high gears and didn't see anything and also nothing when it idles so idk. I have no codes and all gauges were reading normal and nothing sounded weird and there was no loss of power. But something is clearly wrong cus it was pouring so much smoke it was falling onto the highway like a river behind me. The video I took isn't the worst of it but gives a pretty good idea of what it was like.

    I'm waiting till the morning to have a shop look at it but do you think it's worth having them pull the head off to inspect?

    Here is a link to Youtube where Ive uploaded a video clip
    https://youtube.com/shorts/A_Y47cpFcrI?feature=share
     
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  3. JB7

    JB7 Medium Load Member

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    Blue would be burning oil, looks white to me. A lot of diagnostics can be done before pulling the head. "I could see puffs of smoke leaking from the dpf" Should be no leaks in the intake or exhaust. Check, have checked, and take care of the simple things first. They should smoke or pressure test the intake and exhaust piping to start after a visual inspection. Connecting to the truck and getting data from the computer can also tell a lot. Check the coolant level, there may be coolant going into the combustion chamber.
     
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  4. SmallPackage

    SmallPackage Road Train Member

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    What were/are the gauges telling you? Were/are they giving any indication that something wasn’t/isn’t happy?
    Sounds like it was just going thru a good old california clean air regen.
     
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  5. Josiah Harder

    Josiah Harder Light Load Member

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    All the gauges were normal I definitely wasnt overheating but I dont think It was a regen either Ive never seen it do that and even during a manual regen it doesnt smoke like that haha
     
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  6. Goodysnap

    Goodysnap Road Train Member

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    The smoke most definitely has color to it. With no run ability issues, fluid loss or CEL, I would suspect a cracked or breached DPF.

    During a passive regen with a breached DPF, the smoke you’re seeing is unburned hydrocarbons from the regeneration process not being contained by the DPF.

    Wipe the inside of the stacks with your finger. If there is black residue, you have confirmation.
     
  7. SmallPackage

    SmallPackage Road Train Member

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    Check for wet in the stacks. If it is passing enough coolant into a cylinder to white smoke that bad it will have some in the pipe since burning coolant white smoke is mixed with steam.
     
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  8. MACK E-6

    MACK E-6 Moderator Staff Member

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    I thought emissions engines with smoke catchers weren’t supposed to do that.
     
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  9. JB7

    JB7 Medium Load Member

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    I would also check the DEF fluid in the tank to see if you are burning excessive amounts of that. DEF is 2/3 distilled water so excessive amounts could produce white smoke.
     
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  10. Josiah Harder

    Josiah Harder Light Load Member

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    So black residue inside of the stacks would indicate a failed DPF? I was suspecting it might be the DPF since even if I was pushing coolant into my cylinders I didnt think that much smoke would escape past the DPF and out my stacks. Also I was seeing puffs of smoke from around the canister when I pulled over and crawled under. The smell while driving with all that smoke coming out also smelled like what a regen smells like but much worse and stronger
     
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  11. Short Fuse EOD

    Short Fuse EOD Road Train Member

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    Mine does the same. Looks like normal def emissions, especially if outside air is cool. Many drivers don’t notice cause they got weed burners
     
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