DEF IN DIESEL FUEL

[EARL KITCHENS]

I have a friend with a 2104 ECODIESEL and he accidently put less than a gallon of def into his diesel tank that had nine gallons of diesel before he realized it and shut off the def pump.. He started the engine and ran it about thirty seconds. He had it towed to the garage. What bad news should he expect to get from his mechanic? I told him it would be bad!

 

[cevans]

If DEF made it to the injectors, yes, bad. DEF is mostly water, water does extreme damage to diesel injection systems.

Two things - if it *honestly* was 30 seconds, of idling (and not 10 minutes) then it is possible that fuel from the tank didn't make it up to the injectors. The fuel filter is designed to allow water to settle at the bottom, so if the concentration of DEF was very low it might have separated in the fuel filter housing.

What needs to be done? EVERYTHING fuel related needs to get removed and fully cleaned. Every line from the tank to the fuel filter, the filter housing, new fuel filter, after the fuel filter, the hard lines, everything. If any of it is still traveling around the fuel system it will destroy injection components. It will be pricey, but spending the money to clean out the whole fuel system will be way cheaper than replacing HPFP and fuel injectors.

I would also run fuel additives after cleaning to encourage any remaining water contamination to separate. After a few hundred miles I would also drain the fuel filter housing - maybe install another replacement fuel filter.

 

[EARL KITCHENS]

He did exactly what you said to do. No more issues but he did change the fuel filter around 1000 miles. He also told me his mileage seemed to be down a little. Thanks for all your suggestions.