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Fuel Life Span

Discussion in '1982-Present GM Diesel' started by Smitty, Aug 18, 2006.

  1. Smitty

    Smitty 1/2 ton status

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    Any idea how long diesel can sit in a tank before it goes bad? I know gas goes bad over time, but what about diesel?
     
  2. Cricket

    Cricket 3/4 ton status

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    Found this article:

    Diesel fuel begins to deteriorate as soon as it is produced. Within 30 days of refining, all diesel fuel regardless of brand, goes through a natural process called re-polymerization and oxidation. This process forms varnishes and insoluble gums in the fuel by causing the molecules of the fuel to lengthen and bond together. These components now drop to the bottom of the fuel tank and form asphaltene also known as diesel sludge. The fuel begins to turn dark in color, smell bad, and in most cases causes engines to smoke. The engines smoke because some of these clusters in the early stages are small enough in size to pass through the engine filtration and into the combustion chamber. As these clusters increase in size, only part of the molecule gets
    burned. The rest goes out the exhaust as unburned fuel and smoke. With increases in cluster size they begin to reduce the flow of fuel by clogging filters. The filters only address the symptom and not the cause.
    It is estimated that eight out of every ten diesel engine failures have been directly related to poor quality and contaminated fuel. The build-up of contaminates in the fuel systems and storage tanks can quickly clog filters, thus resulting in engine shut down, fuel pump wear, and diesel engine damage.

    Understand that most fuel has some amount of water in it from either condensation or vents. This threat requires that we realize the added burden placed upon diesel fuel as opposed to gasoline. Gasoline acts as a fuel only. Diesel fuel, on the other hand, also must cool and lubricate injection
    system parts. These parts are engineered to very close tolerances - up to 0.0002 of an inch - and any contamination means rapid part wear. Water displaces the diesel fuel. When the fuel is displaced wear occur because lubrication is now absent. Water that enters the combustion chamber results in even more serious damage. When it comes in contact with the heat of the combustion chamber (in excess of 2000 degrees F), it immediately
    turns to steam and often explodes the tip of the injector. Water causes corrosion of tanks, lines, injectors, and greatly reduces combustibility.
    Other areas of concern include the producing more exhaust emissions and effecting EPA standards.
     
  3. 4by4bygod

    4by4bygod 1/2 ton status

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    Good article... in addition to water contamination, you also have bacteria, fungus and yeast to contend with as well.. these can foul a diesel tank very quickly, and with the sulfur reductions, the fuel is at a greater risk than ever before..

    To answer your question, I wouldn't leave any sit for more than a few weeks.. you just don't know what the heck you're getting anymore.

    Tom
     
  4. k5blazin

    k5blazin 1/2 ton status

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    My diesel sat for three years before i bought it and it still ran on the same fuel that was in the tank!!
     
  5. diesel4me

    diesel4me 1 ton status Premium Member

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    me 2!!

    My 82 K20 has sat mostly since I bought it,other than plowing my driveway..it was "down" for 2 years prior to that with a blown motor ,and I ran it just fine on what was left in both tanks....(I'm now using only 1 tank)..

    I've also used diesel that sat for at least 5 years an Elgin Pelican street sweeper we had at the boneyard--we used it in our forkloader,which rarely had more than a few gallons in it!..it didn't look exactly "clear",(more like amber!)but we used it anyway,and it seemed to run OK..

    Not saying the facts are wrong,I'm sure they ARE true,but I think it would take a few years for it to not fire up and run a diesel motor,or cause big trouble...I'm sure they are 100% correct about the water causing damage to injectors,and the other stuff about it not burning completely though..in an ideal world,I guess it pays to always have clean fresh fuel..

    I have added some fuel conditioner or anti-gel every time I put in more fuel,and I hope that no damage has been done by the old fuel in the system when I got it..unfortunately I can't afford to top off the tank,and if it goes stale that quickly,maybe I'm better off NOT too??....:crazy:
     
  6. darkshadow

    darkshadow 1 ton status

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    that is good info, dident know it would turn that quickly
     
  7. colbystephens

    colbystephens 1 ton status GMOTM Winner

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    speaking of water in fuel ... how often do you drain the water from that water/fuel separator on the firewall? if you open the valve on the bottom of it, will fuel begin to start draining after teh water is gone?
     
  8. diesel4me

    diesel4me 1 ton status Premium Member

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    no water??...

    I've "drained" mine into a glass jar several different times,and never saw any water! (you have to open the petcock on top of the filter too,so it can drain,otherwise it might not drain right,if its airlocked)...

    I also drained the "siphon" valve/hose setup the factory put on the fuel tank sending unit, that exits near the spring hanger,and no water came out there either!..so I either have "dry" fuel with no water,or its hiding in the tank,if there is any at all...

    I'd say once a month is often enough to drain the water from the fuel filter,unless you suspect you got a good dose of it recently for whatever reason..I've used a bottle or two of Isopropanol dry gas in wintertime with no troubles--just be sure the bottle says "for gas AND diesel engines"...:crazy:
     

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