Click for Llebroc Click for Nordhavn Click for Glendinning Click for Northern Lights Click for JetForums

Oily film out of exhaust

Discussion in 'Ocean Yacht' started by ShionMcIntosh, Dec 30, 2021.

You need to be registered and signed in to view this content.
  1. ShionMcIntosh

    ShionMcIntosh New Member

    Joined:
    Sep 6, 2020
    Messages:
    13
    Location:
    Emerald Ilse, nc
    Anyone have any idea what would cause this. It occurred after I shut the engines down today and I went back to the boat several hours later and it seems to still happening. Also coming Screenshot_20211230-192225.jpg Screenshot_20211230-192211.jpg out of both exhaust
  2. Capt Ralph

    Capt Ralph Senior Member

    Joined:
    Sep 8, 2004
    Messages:
    10,464
    Location:
    Satsuma, FL
    Un-burned oil or fuel, weeping out.
    If you stick your finger in it, is it dark or smells like fuel?
    How much oil are your engines using?
    What engines?
    What color is your exhaust smoke when idling to the dock?

    The only down hill source I can think of is a leaking turbo.
    Next would be leaking fuel coolers.
  3. mapism

    mapism Senior Member

    Joined:
    Aug 9, 2008
    Messages:
    1,564
    Location:
    Sardinia
    I wouldn't rule out leaking injector(s) either.
  4. KoffeeCruising

    KoffeeCruising Member

    Joined:
    May 27, 2018
    Messages:
    90
    Location:
    Fl
    I had same filmy issue from stbd engine. Ran injector cleaner and it cleared it up.
  5. Capt Ralph

    Capt Ralph Senior Member

    Joined:
    Sep 8, 2004
    Messages:
    10,464
    Location:
    Satsuma, FL
    I was thinking while the engines are sitting, not running, the fuel would not be able to leak up hill to the riser, thru the turbo then down out the exhaust.
    But, oil could leak from the turbine shaft then drain down hill.
    I'm assuming you kids think while idling up to the dock, leaking injectors, over fueling the cylinder, would blow out with the exhaust gases, mix with the exhaust water and be the last to drain out of the transom.
    That could work also.
    Hopefully the OP can answer my questions and help tighten our theories.
  6. Capt Ralph

    Capt Ralph Senior Member

    Joined:
    Sep 8, 2004
    Messages:
    10,464
    Location:
    Satsuma, FL
    Question to all, Does it look like an oil film coming out of his exhaust? Or just coming around the boat from somewhere else?
  7. ShionMcIntosh

    ShionMcIntosh New Member

    Joined:
    Sep 6, 2020
    Messages:
    13
    Location:
    Emerald Ilse, nc
    Got here this morning and it wasn't still leaking out. So I fired engines up one at a time and a steady stream of whatever that is would come from each engine. No smoking and I dipped my finger in it and didn't have a smell and no color. Just weird to me that it's both engines.
  8. Capt Ralph

    Capt Ralph Senior Member

    Joined:
    Sep 8, 2004
    Messages:
    10,464
    Location:
    Satsuma, FL
    How much oil are your engines using?
    What engines & HP tune?
  9. DOCKMASTER

    DOCKMASTER Senior Member

    Joined:
    Feb 26, 2012
    Messages:
    1,001
    Location:
    Ketchikan, Alaska
    Although difficult to tell just from photos, but appears to be diesel vs lube oil. Lube oil tends to stay together more and form circular pattern. Diesel is lighter and thinner and usually leads to the ribbon type streaking you are seeing.
  10. ShionMcIntosh

    ShionMcIntosh New Member

    Joined:
    Sep 6, 2020
    Messages:
    13
    Location:
    Emerald Ilse, nc
    I changed oil in October and haven't run the boat but a couple short runs since then so I don't know how much oil there using since then but this past season they rarely needed oil. They are Cat 3126 420hp 2350hrs. Two new turbos in July 2021 and didn't see this after installing those
  11. mapism

    mapism Senior Member

    Joined:
    Aug 9, 2008
    Messages:
    1,564
    Location:
    Sardinia
    Good point, CR.
    For some reason, I had in mind that it happened upon cold start, rather than after shutdown (as the OP actually said).
    On the other hand, if I understand correctly his post #7, he did experience the same leak also upon cold start, which is indeed a scenario that might point to injectors.
    But I agree with the OP that it would be a weird coincidence if it never happened in the past, and out of the blue it happens on both engines... o_O
  12. rtrafford

    rtrafford Senior Member

    Joined:
    Jul 13, 2019
    Messages:
    1,218
    Location:
    Vero Beach
    I'm going to go out on a limb here and call it on the injectors or fuel cooler. Buildup in the exhaust water during idle running during docking, etc, leaves residue in the exhaust that slowly washes out in a manner where a little goes a very long way. Let the boat sit, and it completes its discharge. Fire it up again, and you're re-introducing the unburned fuel to the exhaust water. So, bad low idle spray or drip from an injector that produces unburned fuel through the valves, or some small amount of fuel weeping within the fuel coolers. Fuel coolers seems much less likely to be happening on both engines at the same time. So injectors...
  13. Capt Ralph

    Capt Ralph Senior Member

    Joined:
    Sep 8, 2004
    Messages:
    10,464
    Location:
    Satsuma, FL
    :rolleyes::rolleyes:
  14. Prospective

    Prospective Senior Member

    Joined:
    Sep 27, 2016
    Messages:
    222
    Location:
    New England
    I get this on my '43 with Volvo TamD 480's. It happens with cold weather. If the water temp drops blow about 50 degrees I get a slight sheen from both engines. But it stops when the engines are shut down and I never see it in warmer weather. I was told it's pretty normal.
  15. motoryachtlover

    motoryachtlover Senior Member

    Joined:
    Jan 29, 2007
    Messages:
    474
    Location:
    smithfield, VA
    I to have experienced this with cold temperatures with my MAN 820s. I was told not to worry about it. I will say I don’t believe I ever saw the same amount of “sheening” as the OP’s pictures show.