Car won't start in cold ; are feathers/sensors in fuel line frozen?

I live in St. Louis and have a 2004 Mazda 3 4-door hatchback. Its been pretty cold in January and February in St. Louis. About 4 or 5 weeks ago my car wouldn?t start. Called AAA and since starter was working fine he never tried jumping it. He ultimately took a rubber mallet out and banged on the underneath rear passenger side of the car on the fuel line/tank (pretty much directly below where my gas tank cap is for fillups) ? AAA guy said there are feather sensors in the fuel line that most likely were getting froze up due to cheap gasoline with water in it that he?s breaking loose.

(It seems to make sense because with as much as he held the accelerator pedal down trying to get it started before banging on it you would have thought it would?ve flooded the engine and it didn?t. I asked him why it didn?t flood and he said because no fuel is even reaching the pistons/engine.) For the past 4-5 weeks since then I?ve been adding ?Heet? to my gasoline and haven?t had any problems up and until this weekend. Saturday night I had to rescue my husband from grocery store parking lot by bringing a piece of wood with me and lightly banging on same area. Just again after driving in from work and letting my car sit for 4 hours I had to bang on it again (I?m getting good at banging by the way, lol). When I park in my garage at home I never have this problem of not starting due to fuel line ?feathers? getting stuck from watered down gasoline. Also I have never had this problem before in the past 7 years that I have owned the car (original owner) and although this winter seems a tad colder than others I don?t think significantly colder. I called the Mazda dealership and the service scheduler didn?t know anything about fuel line ?feathers? as sensor but said he?d ask his technician.

Just curious what you think of all this ?

Banging on the gas tank usually addresses a worn fuel pump problem. (don’t know what ‘feathers’ are). I think it’s more likely your fuel pump is starting to give out, and cold weather makes it worse.

There are no “feathers” in a fuel system.
Attached to the fuel pump is a strainer, and this keeps the pump from sucking up debris that might damage the pump. After the pump, it is straight fuel line right up to the engine, which is usually made of plastic. This hooks up to a metal fuel rail, and then into the fuel injectors.

The AAA tow truck guy feed you a line of malarkey.

When the car fails to start, how much gas is in the tank?
Do you normally drive with a mostly empty tank?


The car currently has a 1/2 tank of gas and each of the last 3 times it didn’t start it had about a 1/2 tank of gas. But yes I normally fill my tank up and drive it til the fuel light goes on and then fill it up to full. It seemed adding “HEET” helped for the past 3 weeks but now that its cold again it seems to be acting up again. Although HEET seems to have helped it might be just a coincidence. What do you think I should have the service station do ? Just curious … when AAA or I have “banged” on underneath of car right below gas cap, what part of the fuel feeding system are we really banging on that is helping the car start again ? (the pump itself or the straight fuel line right up to the engine, which is usually made of plastic … its seems like he/I have been banging on the plastic fuel line and if so why is that helping start the car?)

The pump is in that general area, so it might be jostling it enough to get it going.

Here’s Tom and Ray’s answer to a similar question: