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HELP PLEASE!!! Water in gas tank?

Discussion in 'Gen 3 Prius Main Forum' started by Oso Prius, Feb 24, 2010.

  1. Oso Prius

    Oso Prius New Member

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    I just did something unbelievably stupid and I'm literally sick to my stomach. I just took my car to the gas station to fill it up and go through the brushless car wash.

    After I filled the tank, I got distracted and neglected to put the gas cap back on. I then went through the car wash and then drove home (about 3-4 miles away) without incident. I noticed the gas cap when I got out of my car at my house. It looks like there is nothing there to prevent water from going into my gas tank.

    What should I do? Thanks in advance.
     
  2. ToyotaFleetManager

    ToyotaFleetManager New Member

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    Was the gas door closed or was it opened? That and depending on the type of wash will effect how much water entered the fuel system.

    Worse case scenario is:

    Do Not Start the car. Call a tow truck and have the vehicle towed to a dealer or reliable mechanic. Have them drain the tank and flush the fuel lines if necessary.
     
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  3. samsprius1

    samsprius1 Active Member

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    This is what I would do, add a bottle of iso heet get it at the gas station and fill your car with gas and just drive it like normal.I wouldn't think that much water got in there!

    Good luck,
    Scott
     
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  4. Joe166

    Joe166 New Member

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    I agree with Sam.
     
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  5. 32kcolors

    32kcolors Senior Member

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    The tank was already filled up, so the dilution effect would be far less (assuming any water got in). I'd drive to the nearest gas station and top off again.
     
  6. Tech_Guy

    Tech_Guy Class Clown

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    Please explain "dilution effect".

    Keith

    P.S. Gas and water don't mix.
     
  7. 32kcolors

    32kcolors Senior Member

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    As in less gas available to the engine.
     
  8. Oso Prius

    Oso Prius New Member

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    Thanks, all. I called my local Toyota dealership and talked to a Master Hybrid Tech or somesuch and he said all I need to do is pour a 12 oz. bottle of BG Fuel Drier into my gas tank, which is carried by Napa Auto Parts. I've done that, now I'll let you know if I have any further problems.
     
  9. Jolly Paul

    Jolly Paul Member

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    Wouldn't the anti-vapor flap prevent most water from getting in even without the filler cap installed and filler door open?
     
  10. kbeck

    kbeck Active Member

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    In Ye Olden Days with gravity fed/one direction fuel into a carburetor it was fairly common to carry a little puddle of water at the bottom of the gas tank. This would, naturally, rust the bottom of the tank out after a 100K miles or so. If the puddle was big enough you'd get a big slug of water down the pipe and, natch, the engine wouldn't run. Hence, it was often suggested to stick a can of dry gas into the tank a couple of times a year. This stuff dissolves the water into the gas, at which point your tank becomes "dry". Hence the name.

    However, a fair number of the cars I've owned since then (a) run fuel-injected and (b) run a system where a pump, in the fuel tank, pressurizes the gas and sends it in a pipe towards the engine. At the engine, what gas doesn't get used gets sent back to the tank, through a pressure value, and discharged back into the tank. Hence, if there was a little water down there at the bottom, I'd guess that it would tend to get recycled, lots, and broken into lots of tiny little bits, the better to be burned by the engine without too much trouble.

    I guess I'd be a little more worried about what the soap in the wash would do to the engine.. I don't know. Does soap dissolve into gas or not? I can make arguments either way, since soap is designed to dissolve into grease on one side of the molecule and water on the other.

    However, maybe that's what gas filters are for. In any case: If the man says dry gas, go for it.

    Kbeck.
     
  11. hobbit

    hobbit Senior Member

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    If you drove home afterward, you likely didn't get any
    significant amount of water in there as it would have gone
    right to the bottom and been sucked up by the pump. You would
    have noticed the engine running funny by the time you got home.
    .
    _H*
     
  12. ScottG10

    ScottG10 Member

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    I don't think you got any appreciable amount in your tank either. As Mr. Hobbit said, it would have gone to the bottom and been sucked up first and you surely would have noticed. My advice is don't worry about it and enjoy the ride.
     
  13. hlkc

    hlkc New Member

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    Beside all the member suggestions and follow your tech advice, if I were you I will keep dilute it few more times, maybe fill it up every 100 miles you drove the car and I am pretty sure you will be fine then. But if you can drive home and if you don't feel anything, I won't worry much.
     
  14. Joe166

    Joe166 New Member

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    While that sounds eminently reasonable, in view of the fact that water and gasoline do not mix, means that there is no dilution possible, you are still going to have a small (hopefully) globule of water floating around in your gas tank that could cause a problem if it ever gets sucked into the fuel lines. Putting more and more gas in will only mean you have to put more dri-gas in the tank.

    I guess the alcohol (methanol) in our gas now has a purpose? Doesn't alcohol mix with water?
     
  15. David Beale

    David Beale Senior Member

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    "Dry Gas" or "gasline antifreeze" or whatever they want to call it is usually isopropyl alcohol. It "dissolves" the water and mixes it with the gasoline, so the system can then burn it. An even better thing to use would be ethyl alcohol, but you probably can't (aren't allowed to) buy that in the 95% pure state that should be used. You -can- buy gasohol, which can contain up to 10% ethyl alcohol, which -will- dissolve the water into the gasoline and -will- allow you to burn it. A tankfull of gasohol will contain about a gallon of ethyl alcohol, enough to absorb a -lot- of water! At no extra cost, I might add! ;)

    If available, you could also add a few gallons of E85 to the almost full tank. Cheaper still!

    Ethyl alcohol is much easier on the cars' systems than isopropyl alcohol. In fact, as it is added to your fuel anyway, it's expected by the engineers who designed your car.

    Water in the gas is really no longer a serious issue due to the mandated addition of the alcohol (instead of toxic chemicals such as MTBE etc). Yup, it's political, and yup, it will lower your mileage a bit, but it's actually a "good thing" as the engine will run cleaner.
     
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  16. GrumpyCabbie

    GrumpyCabbie Senior Member

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    The water will 'sink' to the bottom. It will not be diluted in the fuel. It may flow into the fuel lines when on a hill or going down a slope or under hard acceleration and cause problems.

    I know it sounds like a waste of fuel to have the tank drained but it's the safest way. You have just spent thousands on a new car.

    Why risk that investment on a tank of (possibly) contaminated fuel. :(

    But the choice is yours.
     
  17. Oso Prius

    Oso Prius New Member

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    Roughly 100 miles since the incident, and so far so good. Thanks to all for the suggestions.
     
  18. Oso Prius

    Oso Prius New Member

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    Final update. I refilled my tank after about 150 miles and have put a total of around 300 miles on the car since the incident. No apparent side effects at all. Thanks again to all for your thoughts and suggestions.
     
  19. hlkc

    hlkc New Member

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    Congratulation :cheer2: