Unleaded Petrol put in Diesel Tank

[Pearcey]

Finished a cruise and tired crew put unleaded into the diesel tank. Engine was off ...tank has inspection plate ...how do I make sure we get it completely emptied. 31 Moody on a swing mooring with probably 30 litres in the tank - help!

[xymotic]

You don't need to get every last drop, but you just gotta pump it out.

[Anthonyd]

Gasoline has a lower specific gravity than diesel fuel, which means that it is lighter, so if you let the mixture sit for a day or so you can siphon the gasoline off from the top since the diesel will settle to the bottom.

[gts1544]

Pearcey, This might be a great opportunity to "CAREFULLY" clean out your fuel tank! Be sure that any electric pump that you use is "non-sparking" and approved for gasoline! We would hate to lose you! gts1544

[mrm]

Adding gasoline to diesel is a standard operating procedure in very cold climates, especially when one suspects that available diesel was not properly blended for winter. Up to 15% gas to diesel is considered normal then.

In your case, just pump out what you can, fill with diesel and call it done.

[Blue Stocking]

Originally Posted by mrm

Adding gasoline to diesel is a standard operating procedure in very cold climates, especially when one suspects that available diesel was not properly blended for winter. Up to 15% gas to diesel is considered normal then.

In your case, just pump out what you can, fill with diesel and call it done.

+1. Did that with 1 of my trucks when new kid put gasoline in the diesel tank. No problem.

[GrowleyMonster]

A trace left in the tank won't hurt anything. If you are really noid about it, you could try ventilating that tank for a few days. Gasoline evaporates pretty quick. Just beware of where the fumes are going and don't have any spark or flame sources nearby!

[Cotemar]

Originally Posted by mrm

Adding gasoline to diesel is a standard operating procedure in very cold climates, especially when one suspects that available diesel was not properly blended for winter. Up to 15% gas to diesel is considered normal then.

In your case, just pump out what you can, fill with diesel and call it done.

+1, I do this every winter in my VW Jetta Diesel. One gal of gas per 15 gal full tank of diesel

[Rocketman]

As noted already, this is not a big problem, but you will need to some how pump the fuel in the tank out and refill it with Diesel. So depending on you tank and where it is located will determine how much trouble it is going to be to pump it out. If your tank is sitting up high, then a siphon tube 10-20 ft long and several 5 gal tanks to hall off the fuel is all that is needed. If your tank is, lets say, to low to allow siphoning, then buy a small electric inlline fuel pump from an auto parts store, then pump it into again 5 gal fuel cans. If you buy the inline pump, you can leave it in the fuel line for future use when you need to prime you fuel lines when you change fuel filters or if your manual fuel pump ever quites you have a spare ready to go.

[GordMay]

Greetings and welcome aboard the CF, Pearcey, and Anthonyd.

I don’t believe that differing specific gravities between two fluids, in a solution, will prevent them from miscibility*.

With two liquids that are completely miscible, such as diesel and gasoline, the overriding factor is misciblity. These liquids will very quickly dissolve into each other, forming a resulting mixture of petroleum hydrocarbons, containing a greater proportion of higher volatile, lower molecular weight, hydrocarbons than regular diesel fuel; but not so radically different from diesel fuel as to warrant pumping out.

* Miscibility is the property of liquids to mix, forming a homogeneous solution.

[mcarling]

To separate gasoline from diesel, one would need a very tall stack, such as in a refinery. If the 30 litres of gasoline are in a tank of 300 litres or more, just top it off with diesel and you're done. Otherwise, drain most of it and use the mixture as heating oil -- or fuel for a gas turbine.

[tommyh]

Some one did that yo one of our flat beds. The gas distroyed all the seals in the top end and injection system. The truck was never the same again. I would clean it all out.

[Steve Bean]

Growley Monster is right. Be very careful about vapor of petrol
It's heavier than air and explosive. If it contains ethanol I would keep it away from seals as just mentioned.

[David M]

Although gasoline is less dense, it will mix with Diesel. All it takes is a little energy for the mixing to occur, which can come from the boat rocking at the dock. It is not like vinegar and water which will not mix because one is a polar molecule and the other is not.

At the US Naval firefighting school that I went to they used a blend of gasoline and diesel as the fuel source for most of the fires. It does indeed blend quite nicely. The fires by the way had a nice balance between not lighting at all with pure Diesel and incinerating us all or blowing us up using pure gasoline. We were then sent in to dark concrete buildings with a fog nozzle to push back the flames...what fun that was. A petroleum fire can be put out with water if you do it right, but don't try it at home. Use the correct extinguisher for petroleum fires. Sorry, I digressed.

You have to empty the tank but don't worry about what you cant remove because after you fill it up with pure Diesel, the remaining gasoline that you could not remove will be so diluted that it will not matter. Fill it up completely though in order to maximize how much the gasoline is diluted out. Be sure to change your fuel filters and to bleed out any gasoline that might be in your fuel lines.

The biggest problem with gas in a diesel engine is pre-detonation, lack of lubrication and that it can destroy seals.

[hpeer]

Originally Posted by GordMay

Greetings and welcome aboard the CF, Pearcey, and Anthonyd.

I don’t believe that differing specific gravities between two fluids, in a solution, will prevent them from miscibility*.

With two liquids that are completely miscible, such as diesel and gasoline, the overriding factor is misciblity. These liquids will very quickly dissolve into each other, forming a resulting mixture of petroleum hydrocarbons, containing a greater proportion of higher volatile, lower molecular weight, hydrocarbons than regular diesel fuel; but not so radically different from diesel fuel as to warrant pumping out.

* Miscibility is the property of liquids to mix, forming a homogeneous solution.

Yeah, that's what I thought.

I heard two distinct and mutually exclusive ideas roaming about here.

1-That the oil and gas would remain separate and the gas could be pumped out.
2- That the gas and oil would mix and, assuming there was not too much gas, the mixture would be consumable in the engine.

I suspect that if you try to pump it out quickly then you may have some luck. But as the stuff sits and mixes that will become more difficlut.

What I also hears was that a 10% mix of gas into diesel is OK, kinda sorta. But more than that? At what point does it become too much?

So my synthesis of the well meaning advice is:

Pump out the top bit as soon as you can, using a gas rated pump or siphon. Try to get the light gas off the top. Measure it and if you can get a 10% concentration or less you are good. If not, waste the tank of diesel and start over.

Yes?