What about "old diesel"?

[Albinvega27]

Y purchased my new "old" boat last year and the owner had deviated the diesel fuel system, as off the "old" tank. During the winter I have drained the "old" tank, washed out and since the boat was 3 years in a temperate storage and sealed, whatever came out (yellow clear and transparent liquid). When I washed the diesel tank with some new diesel and sucking out the whole stuff, what came out was still clear and transparent. Since, I have filled about 5 Gallons of diesel and run the engine for several hours and it runs smooth. But I still have this canister with about 10 Gallons of "old" diesel, transparent and clean.

My question here is: "Should I use this "old" diesel, or not?" I know the problem can be in the particles in the fuel, but if it is completely transparent? Also, the system has new filter I have set in, so - shouldn´t this filter?

What is a general appreciation here? Is it better to discharge the hole batch and put new one, or to be more "environmental and ecology" friendly and? use the "old" one mixed with new diesel?

[mvweebles]

If it's clear and clean and smells like diesel, burn it. It's diesel fuel.

Peter

[Compass790]

Originally Posted by mvweebles

If it's clear and clean and smells like diesel, burn it. It's diesel fuel.

Peter

+1 with what he said. I've burnt +5 year old diesel no worries in our IDI yanmar

[Joh.Ghurt]

You easily can polish the diesel to remove particles, but when it turns dark like caramel, I've been told it isn't wort the risk using it engine but it still fine for a furnace in a house. But I'm talking here about 15+ year old diesel.

[John_Trusty]

+1 use it. I've used diesel stored over a couple years with stored boats, and never a prob. Treat it with a good biocide treatment (if you have not already) to prevent further growth of algae (or whatever grows in diesel). Getting a small amount of fuel 'polished' is prohibitively expensive.

[tkeithlu]

Leave gasoline around too long ( a few months, even) and the more volatile parts evaporate. Then your lawn mower, small outboard, genset (choose one or more) won't run. Diesel only starts producing flammable vapor at about 150 degrees F. (-40 for gasoline) and diesel engines are not dependent on volatility, so it sits just fine. You can under some conditions grow stuff in it, and it becomes cloudy and slimy, but until then, go right ahead and use it.

[Albinvega27]

Thanks for all the replies! My only worry is the diesel injection pump. I will just mix it with some new One and then install a session with Poseidon, to see if he´approves. If not, I will se him in Hadas...

[sail sfbay]

As others have said the old diesel is OK to burn. I had 3 year old diesel in my sailboat and truck while living overseas and when I came home both started right up and burned it without any issue.

[RiverRat37]

The worst thing about gasoline is ethanol. It's the ethanol that causes the most problems in "old" gas. But one can buy gasoline that doesn't have ethanol. You may have to search for it (most airports sell it because ethanol lowers the power of the gas somewhat -- not a great idea for aircraft). A search on the web can often help find some. The more ethanol, the worse it is. All 2-cycle engines detest old ethanol gas and often fail because of it usually requiring a carburetor rebuild. The whole ethanol-in-gas thing was a very poor idea at best -- except for corn farmers.

Diesel on the other hand doesn't do ethanol. But over time old diesel can grow algae. Not good. I believe there are algaecides to help with this if diesel is going to sit for a long time.

[sail sfbay]

You can have the diesel polished if that will give you more assurance the diesel is OK to use. I have done that on occasions after the boat sat for many years.

OR you can treat with Starcon enzyme diesel treatment then check your fuel filters for plugging.

[lvictorlucas]

I would suggest you polish the fuel yourself. Just get a cheap transfer pump and the smallest micron filter you can and let it run in a loop a few times. If the filter does not plug up just transfer it back into the tank and install the filter after the filter you already have. A pressure gauge across each filter is the easiest way to monitor the filter. Valving the filters is the easiest way to be able to change filters incase one plugs up at a critical time when you don't want to shut the engine down. I usually run a pair of filters in parallel just in case as the fuel is stirred up when going in and out of inlets or during rough weather when losing the engine would be critical. Also don't forget to add biocide and preservative as others have said.

[Joh.Ghurt]

Originally Posted by sail sfbay

As others have said the old diesel is OK to burn. I had 3 year old diesel in my sailboat and truck while living overseas and when I came home both started right up and burned it without any issue.

I wouldn't even start worrying about 3 years. If you have algea and other crud, filter it a few times and you're set. 10-15 years and older can become a problem.

[OBT]

You can add a Cetane booster which will help Make sure it burns properly.

[tkeithlu]

QUOTE " If not, I will se him in Hadas...

We'll all reserve judgement on whether you will meet him in Hades anyway, independent of your burning old diesel in your engine.

[stormalong]

If it is only five gallons why bother to polish it. At $3/gallon it is 15 bucks. See if your local recycle takes old oil and ask them if they can take old diesel. Either that or mix it with fresh diesel and use it.