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kubota engine-diesel fuel in oil?

Discussion in 'Mechanic and Repair' started by smokey, Oct 24, 2005.

  1. smokey

    smokey LawnSite Member
    Posts: 27

    I have a mower with a 37HP kubota engine and all of a sudden there is diesel fuel mixed with the engine oil. I'm thinking it is a head gasket problem,is there any other way fuel can get in with the oil? Thanks for any input.
  2. riches139

    riches139 LawnSite Senior Member
    Posts: 369

    Dead cylinder? Hows your compression?
    Valves, Rings.
  3. TLS

    TLS LawnSite Fanatic
    Posts: 7,940

    Leaky injector is the only reason this can happen.
  4. smokey

    smokey LawnSite Member
    Posts: 27

    If the injector was leaking wouldn't the fuel just get burned or blown out the exhaust?
  5. TLS

    TLS LawnSite Fanatic
    Posts: 7,940

    Not when it sits overnight.
  6. bob

    bob LawnSite Platinum Member
    from DE
    Posts: 4,254

    This is the same thing that happened to my Duramax engine. The problem was, bad injector seals.
  7. fixer67

    fixer67 LawnSite Silver Member
    Posts: 2,100

    I seen this once and it was the injector pump. A seal had gave way where the pump mounts to the engine and fuel was leaking from the pump into the crack case. Those injector can run over 1000 PSI so it does not take much of a leak to cause problems.
  8. niederhauser lawn care

    niederhauser lawn care LawnSite Member
    from Utah
    Posts: 13

    I had a john deere tractor do the same thing. It was the fuel pump. I dont know about your kubota but the john deere tractor fuel pump fuctioned off the engine crank and it leaked in that way.
  9. lawnmaniac883

    lawnmaniac883 LawnSite Silver Member
    Posts: 2,613

    This is definately a bad injector. Same thing will happen on a cummins diesel with a bad injector, it will "make oil". Should be taken to a repair shop for the fix.
  10. rancherman84

    rancherman84 LawnSite Member
    Posts: 3

    any diesel engine can make oil,could be a injector,could be the injection pump,could be the fuel transfer pump.
    these are the only places where the fuel oil and engine oil have a chance to mix.
    these can be hard to track down,take it to a good diesel tech.for diagnosis

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