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water in fuel?

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NutmegCT

NutmegCT

Great Pumpkin
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I've read stories recently about people having engine problems, going to a mechanic, and finding their fuel had water contamination.

If your engine is rough, and/or hard to start - is there a way to tell if there's water in the fuel?

Thanks.
Tom
 
The water will be in the bottom of the tank - does it have a drain? Can you run a hose to the bottom and siphon it to see what comes out?
 
are you talking about Budweiser again?:highly_amused:
 
Mickey Richaud said:
The water will be in the bottom of the tank - does it have a drain? Can you run a hose to the bottom and siphon it to see what comes out?
Click to expand...

That's a great idea. Siphon from the bottom. There a drain plug - but it's a pain to open (what else is new?).

If there's water in the sample - then I move to the Budweiser.

Thanks!
Tom
 
In general aviation aircraft, there is a small push-up valve in the bottom of each wing; during the pre-flight you push up on the valve and obtain a small sample. Since as JP says, the water is at the bottom you will see it in the sample cup.
In your case it will be a little harder to obtain the sample but it can be done.
 
Elliot - when I was taking flying lessons, I remember doing that drain-and-view test of the avgas during every pre-flight. With auto fuel, is it obvious what the water/fuel split looks like? I've googled for some examples, but none are very clear.

Tom
 
Disconnect the line at the carb, put the line into a glass container. Crank it until you get 2-3". You may have all water, and not see a dividing line.
Have a friend who had that happen in Colombia on a Helio. Indians out at the strip had siphoned all the gas out of the 55 gallon drums and refilled with water.
He did the check under the wings, no separation, 50 feet off the end of the strip it quit.

Smell it. Taste it by dabbing the tip of your finger into it and touching your tongue. If it does not smell explosive, and tastes like water, it probably is.

Pull the bottom jet on your carb, drain the float bowl, crank the engine enough to have something resembling petrol, then try it.
 
NutmegCT said:
Elliot - when I was taking flying lessons, I remember doing that drain-and-view test of the avgas during every pre-flight. With auto fuel, is it obvious what the water/fuel split looks like? I've googled for some examples, but none are very clear.

Tom
Click to expand...

Methinks there won't be any separation IF the fuel is Gas/Ethanol. You'll have goo that looks like fat in water.
 
With the fuel sample in a clear jar, let it rest for a minute or two, and you will see clearish "bubbles", or, a stratified layer of liquid rolling around at the bottom. It will be seperated like italian dressing that has been sitting for a while. It will be quite obvious that there are two seperated substances in the jar. The fuel will look like foggy Budweiser, and the water will look like the fluid you drain out of a coconut, kinda clearish white
Outside of a contamination issue from the gas station,it's more of an issue in older cars and power equipment that have vented fuel systems. as the ethanol in the fuel will literally pull the moisture right out of the air.
 
Banjo said:
...
Outside of a contamination issue from the gas station,it's more of an issue in older cars and power equipment that have vented fuel systems. as the ethanol in the fuel will literally pull the moisture right out of the air.
Click to expand...

We're talking about my 1960 Mercedes-Benz. A *very* vented fuel system. And the fuel had been kept in a fuel can with a loosely fitting cap, in a very cold garage, in very damp winter weather. hmmmm

Thanks!
Tom
 
Sta-bil now has a formula specifically designed for ethanol issues. I would look into that.
 
Gas line anti-freeze will get rid of ordinary moisture (as opposed to someone pouring water in) - should have it at pep boys or auto zone
 
Do Stabil and gas line antifreeze actually somehow eliminate the water which came from humid air?
 
Banjo said:
With the fuel sample in a clear jar, let it rest for a minute or two, and you will see clearish "bubbles", or, a stratified layer of liquid rolling around at the bottom. It will be seperated like italian dressing that has been sitting for a while. It will be quite obvious that there are two seperated substances in the jar. The fuel will look like foggy Budweiser, and the water will look like the fluid you drain out of a coconut, kinda clearish white
Outside of a contamination issue from the gas station,it's more of an issue in older cars and power equipment that have vented fuel systems. as the ethanol in the fuel will literally pull the moisture right out of the air.
Click to expand...
Prezactly. Note that the "water" is actually a water/ethanol mix, and is likely still mostly ethanol (over 100 proof but I sure wouldn't want to drink it). Depending on how much dirt and/or dye is present, it may be other colors than off-white.

Here's a shot of what came out of my TR3A after it had been sitting for a few years. It's hard to see the separation mixed in with the crud, but it's there.

DSCF0084_crop_reduce.jpg
 
NutmegCT said:
Do Stabil and gas line antifreeze actually somehow eliminate the water which came from humid air?
Click to expand...
I'm not sure how Stabil works; but the gas line antifreeze is mostly methanol (aka wood alcohol). It works by keeping the water in solution so it can't freeze and block the line. The small amount of water and alcohol mix together with the gasoline and get burned harmlessly.

Ethanol would actually do the same thing, but there is a limit to how much water it can cause to be absorbed. With too much water, the water and ethanol separate from the gasoline. The water/ethanol mix will burn (I once drove my TR3A around town on a gallon of denatured alcohol, which is about 5% water), but requires a much richer mixture than usual.
 
Stabil Blue, Marine version, was designed mostly for boats, as they are very prone to fuel contamination from water, plus it supposedly counter acts the damaging effect of Ethanol on fiberglass and rubber components. Ethanol will eat/soften fiberglass fuel tanks. You don't want that happening in a boat! I use it in all my old gas engine stuff. PJ
 
Drain it all out and start with fresh.
It's lawn mower season.
 
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