Some of this discussion has moved from talking about diesel fuel in generators
and moved to diesel fuel in automobiles. I skimmed through my file of "car
talk" columns from the newspaper and found a familiar column which I had read
last year. I was surprised by the apparent severity of even small amount of
diesel, such as 1 gallon in 20, in the fuel for modern gasoline engines. I
found this same article on the Internet and I've copied it below, along with
appropriate credit to the authors (who have written several good books).
I am curious how extension the recommended fix would be if this person
had actually run the engine with the diesel-gasoline mixture. All his wife
did was put the mixture into the fuel tank.
Tom & Ray Magliozzi
(The "Car Talk" guys)
Dear Tom and Ray:
This evening, my overworked, overbooked, type-A wife accidentally put about 3.5
gallons of diesel into her nearly empty 1998 Honda Odyssey. Upon realizing her
mistake, she filled up the rest of the 12-gallon tank with gasoline. At that
point, she wisely decided to call me before trying to drive it. I told her to
park it, and I immediately called two mechanics to get their advice. I first
called the dealer, and he said not to drive the car and to have it towed in. He
said he would have to drain the gas tank and steam-clean it to get the diesel
out and then check to see how far into the system the diesel fuel might have
gotten. If we were lucky, it wouldn't have gotten sucked into the fuel pump,
the fuel line or the injectors. If we weren't lucky, the dealer sure would be!
Then I called my trusty curbside mechanic, who comes to the house with all his
tools and equipment in his truck and always provides me with reliable repair
service for about a quarter of what the dealer quotes. He said that we probably
could drive it. It would smoke some while the diesel burned out, but he thought
that it might be OK, except maybe we would have to replace the oxygen sensors.
I usually like to take the path of least resistance, but in this case I felt it
would be better to be safe than sorry, and we had the car towed in for service.
What should we do before driving it? Thank you, and don't fuel like my wife.
RAY: Well, I think the dealer gave you the correct advice, Neil. But you might
not need to be quite as thorough as he's suggesting. And you certainly don't
have to let him do the work, if you like your buddy, Crusty McToolbox, better.
TOM: It sounds like your wife never even ran the engine with the diesel fuel.
So, we can say with confidence that none of it got into the fuel lines. All of
it's still in the tank.
RAY: The tank needs to be removed and drained. You can probably skip the
steam-cleaning phase, as I'm guessing that less than half a cup of diesel will
remain on the fuel-tank walls.
TOM: After you reinstall the tank and refill it with gasoline, I'd have Crusty
remove the fuel line where it joins the fuel rail, up in the engine
compartment. Then you can cycle the fuel pump (without running the engine) and
take a sample of the fuel in a glass bottle. Let it settle out and see if it
looks clean. Do this several times, or until you get good, clean-looking
gasoline. Then hook everything back up and drive it.
RAY: The fuel injectors shouldn't be bothered, even if there is still a tiny
amount of diluted diesel fuel in the tank -- it'll just burn right up in the
cylinders without any problem. Crusty is right, though, that if you ran a
quantity of diesel through the engine, you'd be putting the oxygen sensors at
real risk. And they're not cheap to replace.
TOM: But I don't think the diluted remnants of half a cup of diesel fuel in 12
gallons of gasoline will do any harm. Of course, if we're wrong and your fuel
system is ruined, let us know, so we can warn the next poor schlub who does
this. Good luck, Neil.