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Diesel in oil Cat 3160

Discussion in 'Engines' started by perdiem, Mar 3, 2013.

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  1. perdiem

    perdiem New Member

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    I have a Cat 3160 (forerunner to the Cat 3208 natural) that is getting fuel in the oil. I have had all the connections in the fuel return system changed and now the injectors have been removed and are at the shop getting checked. We also changed the fuel lift pump with a spare. I've been told that if servicing the injectors doesn't cure the problem, the only other place fuel can get into the oil is from behind the fuel injection pump. Is this true? Is there anything else we should try before removing the injection pump?

    Thanks,
    Gregg
  2. Old Phart

    Old Phart Senior Member

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    I dunno
    Are you talking about a Cat 3160 or a Cat 1160, which is the forerunner to the Cat 3208?
  3. PacBlue

    PacBlue Senior Member

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  4. Capt Ralph

    Capt Ralph Senior Member

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    Was that a large increase of sump oil (pints,quarts,gallons / hour?), is there any smoke? loss of power ? New vibrations?
  5. perdiem

    perdiem New Member

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    Are you talking about a Cat 3160 or a Cat 1160, which is the forerunner to the Cat 3208?

    I believe my 1974 Cat 3160 marine engine became the 3208 natural in 1975.

    Was that a large increase of sump oil (pints,quarts,gallons / hour?), is there any smoke? loss of power ? New vibrations?

    I forgot to mention the smoke. That is what we first noticed. No vibrations or loss of power and maybe a liter (quart) an hour of excess oil. I am going to pick up the injectors this morning so we'll see what they have to say.
  6. dennismc

    dennismc Senior Member

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    It would surprise me if injectors are the issue, that's a fair bit of fuel to get into the sump from faulty injector (s)
    My suspicion would be the fuel pump and would advise confirmation before refiring up the engine, possible runaway exists. I once had a Waukasha gen set with a Stanadyne fuel pump that passed fuel into the crankcase.

    Good luck....
  7. dsharp

    dsharp Senior Member

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    The 1160 was the number for the truck engine. The injectors on the 3160 and 3208 are similar but, the injector pumps any completely different. I don't think they ran a fuel cooler on that engine so the lift pump is about the only place that would leak fuel in the engine oil. I think there is a seal on the injector pump that could leak fuel inside the front housing but, I would take a look at the fuel pump first. I know the gas pumps leak internally to keep from dumping gas in the bilge but I'm not so sure about the diesel pumps. I burnt up a brand new 454 Mercruiser long block re-using a fuel pump and swore to never put and old one on again.
  8. Capt Ralph

    Capt Ralph Senior Member

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    I hope you kept track of what injector went where AND the shop tells you what injector tip was blown. You will have to keep track of that cylinder. Over-fueling a lung will cause fuel in the sump. It also washes away needed oil for proper piston & rings. Worst case includes bent push rods, bent rod, damaged piston. Hopefully you did not run it hard or much when smoke was observed. BTW, what color was the smoke. White or white/grey that brings tears to your eyes would be an over-fueled injector. Low compression (rings, valves) the same.
    Faulty pump would cause fuel in the sump and some blue smoke. Not good either. I'm NOT a Cat expert, but the design has been around many engines and a long time. I don't think the fuel pump would leak that much thru the block & into the sump.
    Please keep us up to date.
  9. 993RSR

    993RSR Senior Member

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  10. K1W1

    K1W1 Senior Member

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    Hi,

    Any update on this issue?
  11. Bryant

    Bryant New Member

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    hi,

    When you put the injectors back i think there should be x2 crush rings with like a wierd looking o-ring in the middle. i know if you dont heat up the crush rings they wont seat right and thats where you can run into problems. are the fuel lines internal or external?