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Factory Warranty and E-15

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  • 1 month later...

A decent video . . . BUT I suspect that "Car Coach" needs to re-check some things. The "High Aromatic Fuels" warning and disclaimer of warranty coverage had been around since the middle 1980s. Remember "gasohol" in the 1980s? It's all in the owner's manual and warranty documentation, just few people read that far.

Almost all fuel lines on modern vehicles have been plastic for many years now, not metal. There is still metal in the fuel systems, though, as in fuel pumps (gear or vane style) and their related "modules". Plus the fuel rails on the engine, rubber in the fuel pressure regulator diaphram, and the injectors themselves. All of these things will be subject to the "acidic" corrosion and "drying of the rubber" which have been experiences in older vehicles with metal fuel lines and carburetors.

There is one YouTube video which shows phase separation happening in the open air with a fan blowing air across a container of E10 gasoline. In about 30 minutes, it's happening. BUT all late model fuel systems are "sealed" and vent through a complex mix of valves, containers, canisters, and lines -- not quite the same as "open air". Therefore, I highly suspect that phase separation would be much less prevalent in a newer vehicle, unless the fuel cap was left off in a humid environment. Just my suspicion . . .

I have a 2005 Impala, which I recently purchased, which had 69K miles when I purchased it. Not long after I bought it and drove it, the temperature turned "cold". In those cooler temps, it smelled like a fuel tank from under the hood, but when warmer, no significant smells. The fuel regulator was failing. The tech said it was corroded like it'd been leaking for some time.

Internal to the regulator is a rubber (I suspect) diaphram, which works against spring pressure to maintain enough fuel pressure for the injectors to "fire". As the car was that old with that few miles, I suspect it might have sat around long enough for the fuel system to become "dry". Elsewhere in these forums, there was a thread about mechanical fuel pumps and the best material for their diaphrams . . . end result is that even THAT material, which is know to be "ethanol resistant", would resist the ethanol as long as it was "wet", but when it might become "dry" for a period of time, the rubber would become brittle and fail when it was wetted by fuel again. Other than the "corrosion" issue, I somewhat suspect this might have been an issue with the fuel pressure regulator "leaking". A new fuel pressure regulator and all is well.

At one time, I suspect that conversion to an electric fuel pump might be an alternative for older vehicles . . . until I realized that many such fuel pumps have metallinc parts in them, which might be subject to corrosion from ethanol'd fuels going through them. Again, possibly becoming "dry" in an ocassional-use vehicle "between uses". Not to forget the need for some sort of pressure regulator in the fluid circuit, too!

Recently, I found an advertisment for a new product from Joe Gibbs Racing, which was another "ethanol" fuel additive. I found it online and it sounded good, until it specifically mentioned that it would not prevent phase separation. So much for that.

Some enthusiasts "wash" their gasoiine before putting it in their vehicles. They intentionally introduce water into the gasoline, to encourage phase separation and remove the ethanol/alcohol content from the fuel. As the video mentioned, this will lower the octane of the fuel by about "three numbers". BUT . . . another thing she might desire to re-check . . . all modern vehicles have electronic ignition timing controls, with "knock sensors", so a decrease in octane might lead to slightly less power, marginally I suspect, but not "engine damage" as the computer compensates for all of that. In an older vehicle where the fuel's octane can be critical, knocking the initial ignition timing spec back a few degrees might decrease any "clatter" tendencies enough to be safe--which can be a highly-variable situation, depending upon the engine and the owner's driving style.

Thanks for posting that link.

End result . . . use gaoline with NO MORE than 10% ethanol in anything, UNLESS it's certified as "FlexFuel" by the manufacturer (with appropriate emblems on the outside fo the vehicle to indicate such OR the "FlexFuel" option can be determined by the vehicle's VIN). If a modern vehicle's fuel pump fails "too soon", take a sample of fuel from the tank and check it for ethanol content. Such fuel pump replacements can usually approach or exceed $700.00.

On older vehicles, check ALL rubber fuel lines for signs of seepage, as the line will be dried-out and fail from the inside out. As the oils are removed from the rubber (by the "cleaning action" of the ethanol), it will become porous and progressively work to the inner reinforcement layer of the rubber fuel lines. ALSO, don't forget about the accelerator pump diaphrams on Holley 2bbls and 4bbls, which are in the bottom of the float bowl, actuated by external linkage!!!

On older carburetors with machined fuel passages, "sealed" with a ball bearing and solder on the exterior of the carb, the ethanol can degrage the solder and cause a HUGE fuel leak, as many of those passages connect to the float bowl of the carb. Something else to periodically check for!



Edited by NTX5467 (see edit history)
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