What is the purpose of a fuel filter? How much do they usually run cost-wise?

Question

I realize that it "filters." But what the heck does it filter. It's not like debris gets into your gas tank or if so, I haven't the slightest idea how. I have a Haynes Manual for my truck so I know how to replace it and how often--I just don't know what exactly their purpose is.

Answer 1

Actually, plenty gets into the gas tank. I've opened one from an older car, and it was filthy inside. You can get dirt, sand, anything that might get carried in by the wind while you're filling up, or even if the person before you dropped the hose on the ground. Plus, gas tanks can start to rust, and bits break off in the inside. Without the fuel filter, any of this stuff can clog up the tiny passageways in your carburetter or fuel injector(s) and cause a rather expensive repair. As for the cost, older cars with a carb generally have a small filter just inside the connection between the fuel line and the carb itself. These can be as cheap as $2-3. On fuel injected cars, and some others, will have one in the fuel line somewhere under the vehicle or inside the gas tank. These can run more, possibly $20 or more. However, it is still cheap insurance when you consider the possible alternative repair bills. Also, if the filter is one of the ones between the carb and the fuel line can usually be removed with a pair of wrenches, while the ones in the line or in the tank require more tools, and sometimes specific ones. Some of these, however, can be duplicated by commonly available tools and materials.

Answer 2

Fuel Filter Purpose

Answer 3

fFOR MORE INFO GO TO:http://en.wikipedia.org/wiki/Fuel_filter

Found in most internal combustion engines, a fuel filter is a filter in the fuel line that screens out dirt and rust particles from the fuel. Fuel filters serve a vital function in today's modern, tight-tolerance engine fuel systems. Unfiltered fuel may contain several kinds of contamination, for example paint chips and dirt that has been knocked into the tank while filling, or rust caused by moisture in a steel tank. If these substances are not removed before the fuel enters the system, they will cause rapid wear and failure of the fuel pump and injectors, due to the abrasive action of the particles on the high-precision components used in modern injection systems. Fuel filters also improve performance, as the less contaminants in the fuel, the more efficiently it can be burnt.
Cost depends on what type of vehicle you have.

Answer 4

You will indeed get crap in the fuel. I cut open a couple of filters with a hacksaw to see if there was any crud inside them and sure enough there was a considerable amount. If you have a fuel injected vehicle its critical to filter the gas as a small piece of crud can clog up your injectors. You can go to long without changing the filter and eventually your car will start sputtering as it is being starved for fuel do to the amount of crud in the filter. The fuel injected vehicles usually have the filter underneath the car and are in line with the fuel line. Your owners manual should tell you how often to change them. They should be good for at least 30,000 miles or more depending on the make of your vehicle.

Answer 5

Nowadays, the fuel pump is located inside of the fuel tank and is usually electric. The pump creates positive pressure in the fuel lines, pushing the gasoline to the engine. The higher gasoline pressure raises the boiling point. Placing the pump in the tank puts the component least likely to handle gasoline vapor well (the pump itself) farthest from the engine, submersed in cool liquid. Another benefit to placing the pump inside the tank is that it is less likely to start a fire. Though electrical components (such as a fuel pump) can spark and ignite fuel vapors, liquid fuel will not explode (see explosive limit) and therefore submerging the pump in the tank is one of the safest places to put it. In most cars, the fuel pump delivers a constant flow of gasoline to the engine; fuel not used is returned to the tank. This further reduces the chance of the fuel boiling, since it is never kept close to the hot engine for too long.

The electric fuel pump is generally on whenever the car's ignition switch is in the "on" position. Depressing the gas pedal results in the throttle body opening on the engine (metering the air going in) rather than engaging the fuel pump. The ignition switch does not carry the power to the fuel pump, instead it activates a relay which will handle the higher current load. It is common for the fuel pump relay to become oxidized and cease functioning; this is much more common than the actual fuel pump failing.

Some cars with an electronic control unit have safety logic that will shut the electric fuel pump off even if the ignition is "on" if there is no oil pressure, either due to engine bearing damage or a non stalled engine, e.g. in a car accident. In case of an accident this will also prevent fuel leaking from any ruptured fuel line. Other cars have an additional roll over valve, that will shut off the fuel pump in case the car rolls over.

Answer 6

Do you think that fuel is clean? It sits in a tank at the gas station that who knows when has it been cleaned!! You would be surprised at what kind of dirt is in a fuel filter that hasn't been changed! The purpose of a fuel filter is that it cleans most of the fuel before it reaches your injectors!!! It cost $20 to 30 dollars for a fuel filter compared to over a $1000 for new injectors that are damaged caused by dirty fuel !!!

Answer 7

you have to remember your tank is not the only thing the gas sits in, and none of the containers including your tank are sterile. 1/100 of an ounce of dirt every tank can add up after 30,000 miles. The cost depends on what you drive, an old school inline filter off a dodge 225 slant six would be $1.99. Some fuel injected filters and diesel filters can run $100 or more

Answer 8

Although there are no impurities in petrol/gasoline sold at retail outlets, they still manage to get in to your fuel tank. When you're filling up, airborne dirt sneaks in and - especially in older vehicles with metal tanks, the lining of the tank begins to break down and small flecks of metal, rust and similar can make their way into the fuel line.

The filter will absorb this. On your new vehicle, you really shouldn't have to change them unless you live in a dusty climate. Even then, an aftermarket in-line fuel filter replacement will cost only a few dollars compared to the vehicle's brand name filter, which is often exactly the same.

Answer 9

Fuel is one of the sources for the most dirty and contamination entering your engine. Since fuel has to be atomized, it passes throught some very tiny places. Any piece of dirt or rust flakes can plug that up in a hurry. In addition, the abrasivness of the dirt in fuel will cause problems inside the engine.

A fuel filter must be changed because they rapidly get full of contamination and dirt.

Just watch the gas truck make a delivery to the gas station. The fuel from that dirty truck is pumped through a dirty hose into a tank in the ground through a hole in the concrete. More dirt gets into fuel than you might think. change that fuel filter.

Answer 10

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RE:
What is the purpose of a fuel filter? How much do they usually run cost-wise?
I realize that it "filters." But what the heck does it filter. It's not like debris gets into your gas tank or if so, I haven't the slightest idea how. I have a Haynes Manual for my truck so I know how to replace it and how often--I just don't know what exactly their purpose...