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Water in gas tank = frozen fuel filter

Driving down the highway yesterday, my car suddenly lost power and would not restart. I got a tow to a garage and the guys there told me there was water in my fuel that froze the filter. (I live in Philly, and it has been colder than average this winter.) Has anyone heard of this happening before? How does the water get into the fuel? Did I get a bad batch of gas, or is there a way the water could have seeped in from outside from snow/rain? I am hyper-sensitive about water getting into cars because my previous car was nearly destroyed by a leak! Any insight is appreciated! Thanks!


  • edited January 2011
    I've heard of fuel lines freezing but never specifically the fuel filter. My understanding is that there is water that disolves in the fuel from the ambient air, athough it could be a leak at the filling station. Without any additional info, I would talk to the mechanic fixing the car to get their opinion and repost with what they said. When I lived in Michigan and it got to be 'colder than average' (according to my dad) we would add something called "dry gas" to the fuel tank. I believe the idea was flamable but also was slightly polar (molecularly speaking) to keep the water from forming solid ice crystals and then you pass it through the fuel lines and engine as a liquid and through the exhaust as steam.
  • edited January 2011
    Its called gas line freeze. Used to be a big concern 30 years ago but with the alcohol in the gas now, not as much. Use a bottle of Heet de-icer in the tank once in a while in the winter to clear the water out if you are susceptible to it.

    You may have gotten some water with the gas but I suspect you may not keep your tank as full as you should. When you let your gas tank get down below 1/2 tank, there is air in the tank. When the air cools, it cannot hold as much water as warmer air, and water droplets condense inside the tank. Keeping your tank at least 1/2 full or more reduces the change of water condensing in your tank.
  • edited January 2011
    I live a little farther north in New England, and no, I have never heard of a frozen fuel filter. But I never let my gas tank go lower than half-full and never buy spot-bought gasoline at the off-brand gas stations.
    If you have been driving the car for some time until it is almost out of gas, OR /AND you always buy the cheapest gas wherever it can be found, you might have both water in your gasoline and managed to clog up your inline fuel filter. I don't expect any ice, actually, just a cold unignitable mixture of water and gasoline.
    It's cheap enough to replace the filter and add a dose of dry-gas. Then keep the gas tank at least half full with if not brand name, at least quality gasoline.
    Try these and let us know.

  • edited January 2011
    Most of the gasoline sold today contains ethanol, grain alcohol, which offers some protection against fuel line freeze-ups..But water CAN get in, usually from a gas station with leaking tank covers or missing tank covers...In this way, moisture can be introduced to your fuel tank..A very small amount of moisture will cause the gasoline, ethanol and water to separate into three layers in your gas tank..When this happens, the entire contents of the gas tank must be drained, the filter replaced, and fresh fuel pumped into the tank..

    To simply replace the filter and drive on with no further problems would be quite rare..Perhaps your filter was simply plugged up and in need of changing..
  • edited March 2011
    I also live near philly and have the same recurring problem. Do I see that you also drive a Jetta. Mine has had the check engine (emissions) light come on frequently. Each time the code says mass air flow sensor error. The car has been checked for vacuum and coolant leaks and the sensor has been replaced numerous times but the problem keeps coming back. I've noticed that the last 2 times it was when the weather suddenly got cold again and the gas tank was less than 1/2 full. Did the dry gas help you out?
  • edited March 2011

    I've seen it many times...but not in 20 years or so.
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