How long can diesel sit? - Page 2 - PeachParts Mercedes-Benz Forum

t walgamuth · #1 02-28-2008, 04:12 AM

Quote:

Originally Posted by Colorado220

Thanks, is there a way to test for alge? or just pump some out and look?

I guess you didn't read my long post. Cloudy.

Tom W

jamesNB · #2 02-27-2008, 11:36 PM

I'd drain the fuel out of the tank. The main concern you have now is getting the car started. I'd recommend changing all the fluids (fuel, oil, trans fluid, diff oil, coolant ect).
Also, when a gas engine has set for a while, it's a good idea the pull the plugs and squirt some Marvel Mystery Oil or transmission fluid into the cylinders to make sure the pistons are free. I don't know if that is recommended for Diesel engines. Maybe someone else can chime in.

t walgamuth · #3 02-28-2008, 04:17 AM

Quote:

Originally Posted by jamesNB

I'd drain the fuel out of the tank. The main concern you have now is getting the car started. I'd recommend changing all the fluids (fuel, oil, trans fluid, diff oil, coolant ect).
Also, when a gas engine has set for a while, it's a good idea the pull the plugs and squirt some Marvel Mystery Oil or transmission fluid into the cylinders to make sure the pistons are free. I don't know if that is recommended for Diesel engines. Maybe someone else can chime in.

I would definately not dump the fuel without checking it for bacteria. It is a smelly messy job and what do you do with the fuel after you drain it? It is much more likely to be good than bad, IMHO.

Even it it does have bacteria, you can treat it with biocide and run it. After a treatment the dead bacteria will flow through the filter and burn off.

About the only reason to drain a tank imho is if you are changing the tank (a very unlikely thing).

Tom W

jamesNB · #4 02-29-2008, 12:42 AM

I still say drain the tank. That will eliminate bad fuel as a variable and also get any gunk out of the tank. If the fuel is bad you'll end up chasing your tail trying to get it started and running smoothly. If there is water in the fuel you'll be able to see it settle out in the bottom of the container. I had a Mazda (back when they were good and made in Japan) and the owners manual recommended draining the fuel tank once a year. Of course I'd run it down to Empty before draining it. It was easy because it had a plug in the bottom like the oil pan.
Drain it and save yourself some headaches.
As for disposal you can:
1. Filter it and add it back to the tank a couple of gallons at a time once it's running fine.
2. Use it for cleaning parts.
3. An oil disposal place should take it.

t walgamuth · #5 02-29-2008, 07:04 AM

the advice you got for your gasser mazda is not good advice for a diesel.

Diesel hardly ever goes bad. If it is contaminated with bacteria a treatment with biocide will kill it and render the dead carcasses harmless.

Even if you do drain out water and bacteria contaminated fuel you will still need to treat the tank with biocide to kill the residue that will not drain out easily.

You are not being helpful in stubbornly continue to recommend this useless action.

Tom W

jamesNB · #6 03-01-2008, 02:13 AM

Quote:

Originally Posted by t walgamuth

the advice you got for your gasser mazda is not good advice for a diesel.

Diesel hardly ever goes bad. If it is contaminated with bacteria a treatment with biocide will kill it and render the dead carcasses harmless.

Even if you do drain out water and bacteria contaminated fuel you will still need to treat the tank with biocide to kill the residue that will not drain out easily.

You are not being helpful in stubbornly continue to recommend this useless action.

Tom W

Stubborn? Yes. Bad advice? I doubt it.
Twelve years is a long time to let anything sit. I don't care if it's gasoline, Diesel Fuel, or asphalt. Drain all the fluids, including the fuel. Eliminate it as a variable. What is it going to hurt?
Surely you know bacteria and algae aren't the same creatures? Nonetheless, if there is or was crap growing in the tank, dead or alive, it will clog the filters. If there were organisms growing in it, surely you realize that has changed the composition of the fuel?
Even if there's no sediment, rust, crust, gunk or water and the fuel is crystal clean, what was put in it last? DF1? DF2? Who knows? It can make a difference.
Drain the tank and clean it. Worst case, it took a couple hours and if it doesn't fire up, you know the fuel's not the problem.
I can't believe you think draining the fuel is "useless". I believe it is common sense.

jamesNB · #7 03-01-2008, 05:57 PM

Quote:

Originally Posted by jamesNB

As for disposal you can:
1. Filter it and add it back to the tank a couple of gallons at a time once it's running fine.
2. Use it for cleaning parts.
3. An oil disposal place should take it.

Any place that takes old paint should take fuel. Ultimately, it's burned in cement kilns, or used to boil water to turn turbines. The tough stuff to get rid of are the chlorinated hydrocarbons like chlroform, methylene chloride and pesticides.
I was a chemist at a private lab that had contracts with oil companies, engine manufacturers and engine component manufacturers, and the Federal Government.
Later I went into clinical chemistry and then organic chemistry. About 8 years ago I made a radical career change. Now chemistry is just a hobby. (extracting essential oils from plants, making environmentally friendly pesticides and wood preservatives, making soap and a couple other Skunkworks Projects and keeping up with current research).

jamesNB · #8 02-27-2008, 11:47 PM

A more direct answer to your question, as Diesel Fuel ages:
1. Water can get into the tank from condensation
2. The lighter hydrocarbons can evaporate and make starting harder and gum up the works.
3. As mentioned above, bugs can grow in Diesel Fuel. If growth is prevent, the fuel will be cloudy.
On a final note, all diesel fuel is really old. Like dinosaur old, lol. Had to through that in.

babymog · #9 03-01-2008, 10:26 AM

The bacteria "algae' that grows in the diesel tank is in the boundry layer between the fuel and the water. Doesn't change the fuel.

Diesel fuel will oxydize, it does change the fuel, but it is still combustible in a diesel engine. Will it yield full rated BTU? No. It will probably burn less efficiently so you'll have less mileage and power, probably not noticable. It will not do any damage to the engine.

You can pump a little fuel from the bottom of the tank (or siphon) to see if there's water in it, let it settle for a while in a clear container and you'll see it if it's there.

If it doesn't have water in it, don't worry about it. Filters are important though, I recommend carrying a filter or two until you're sure it won't be fouling filters.

RUN-EM · #10 03-01-2008, 10:41 AM

After all, it already has a few million years of aging start on it. "New" purchase of SDL had 10 year old diesel in it. Added lucas fuel injection cleaner to it and fired right up. Smoked and clattered a bit but cleared up after driving a while.

Regards

Run-Em

babymog · #11 03-01-2008, 04:21 PM

I had 265gallons pumped out of one of my motorhomes, bad algae problem, the truck service place pumped it into empty 55gallon containers and used it for heat.

babymog · #12 03-03-2008, 09:36 PM

Old diesel would probably be bad to have in contact with the fuel system components for a long time, but it's already done that.

You're just considering what effects having it in contact with that system for another couple of days or so as you run it out. No significant contact time.

If there's water in the fuel tank, get it out. If there's "algae" in the fuel tank, get it out. If not, the filter will take care of particulates, keep spares around, and you'll be diluting the fuel with fresh fuel as you drive and fuel the car.

Best thing is to get it running and get fresh fluids in the engine. The oil pH is more important than the fuel pH, and the coolant pH + SCAs is important, the fuel is consumable.

You're getting "wrapped around the axle" on this fuel thing, step back and take a broader look.

#13 09-21-2009, 08:15 AM

I would be willing to bet that the fuel will be just fine. I've burned fuel so old it was probably pumped out of the ground using a steam engine with no trouble whatsoever. If you can start the engine on it, burn out about 10 gallons, fill up the thank and then change the fuel filter.

As for the 2,500 gallons in the storage tank, it would have been wise to use a more subtle method of pumping it into your vehicles. You didn't need to meter it, so you could have used a hand pump or an electric pump like the contractors use on the tanks in the back of their pickups to fuel construction and farm equipment. Oh well, hindsight is always 20 20.

vstech · #14 09-21-2009, 09:18 AM

ok,
here's what I would do.
get a good gallon container and fit 2 5/16" fuel lines in it.
disconnect your fuel lines from the tank lines in the engine compartment, and test out the car from that. after you have the vehicle running right, try the fuel in the tank.
this way you are not trying to figure out what's in the tank vs. just getting the car running.

mplafleur · #15 09-21-2009, 11:42 AM

My SDL had 7 year old fuel in it by the time I got the motor rebuilt. I through in some biocide and it drove just fine. Almost a full tank too!