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Water in gas tank and possible ruined fuel pump

We began having problems with surges & hesitations shortly after filling our tank at the local station. We called the station and the owner tested the station tank. Nothing showed up. The next day the problem with our car continued and the check engine light came on. We took the car into the dealership and their testing said we needed to replace the fuel pump. We later found out that there was water in the station tank and thus in our car tank. My question is: can water in the fuel tank ruin a fuel pump?
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Comments

  • edited January 2010
    Yes, and any dealer or shop who tells you that water is involved should be prepared to take a sample of at least a quart and keep it for your inspection.
  • edited January 2010
    Tell the fuel station of your complaint. Tell the fuel SUPPLIER of your complaint.
  • edited January 2010
    Fuel pumps are designed to pump liquid, and gasoline is not much different than water. I once had a vehicle into which a large amount (many gallons) of water was pumped. The mechanic disconnected the fuel line and used the vehicle's fuel pump to empty the gas tank.

    The engine ran poorly for about a week until the last bits of water made their way through the system, but there was no permanent damage and the fuel pump continued to function normally.
  • edited January 2010
    Can water ruin a fuel pump? Maybe. I'm skeptical. As you are probably aware, air slips into the tank as you burn off fuel and that air can contain a fair amount of water vapor -- especially in humid climates. The water then condenses on the cold walls of the tank at night and ends up at the bottom of the fuel tank where it is sucked up by the fuel pump, mixed with the gasoline and burned harmlessly. (Some of it dissolves in the gasoline and is burned that way)

    Folks in cold climates frequently dump a pint of isopropyl alcohol into their gas tanks in the late fall to help dissolve and get rid of the Summer's accumulation of water in the tank before it freezes and causes trouble. Fuel pumps have to be designed to deal with the worst cases of water accumulation in the fuel tank. And Toyota tends to build their vehicles like tanks. Their fuel pump probably will not be flimsy.

    So, maybe the fuel pump is damaged. And maybe it isn't. You should at least hold open the possibility that the folks at the dealership don't know what they are talking about.

    You can either have the fuel pump replaced which may not be outrageously expensive. On many Japanese cars, the fuel pump is quite accessible and can be replaced without dropping the fuel tank. Or you can get a second opinion from a good independent mechanic. Or you can do your own checks if you have some basic tools, some time, and the inclination.
  • edited January 2010
    Reference the old cold weather practice of adding isopropyl alcohol or "dry gas" to the tank to soak up water. Now that almost all gas contains at least 10% ethanol in the winter months, is there any need to continue the old dry gas treatments?
  • edited January 2010
    The tanks would have to be leaking for this to occur. Ethanol should make water content a thing of the past.

    I too don't see why a fuel pump would fail with water while not with a solvent like volatile. Fuel has no lubrication qualities.

    Now if it's fouled with stuff contained in the water, that's another story, but the sock and the mesh that's on the inlet of the pump should protect it.
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