Contaminated Diesel Fuel


Contaminated Diesel Fuel

Algae in fuel tank

21 March 2011
10:00 PM
Well despite my best efforts this past 4 months while parked at NAS Key West my diesel fuel developed algae.  I kept tank full and several times put in some fresh fuel from a busy station. But all I could add was 7-10 gal we used for genset several times.  As we headed out this AM I noted the engine bucked a little as we "climbed" the overpasses on the turnpike.  Not too bad, but noticeable. I stopped and drained some fuel from the filter and it had little black furball looking pieces in it - I assume that is algae.  I debated on whether to introduce new fuel or to drive as far as safely possible to use the exiting fuel before adding new fuel and opted to introduce new fuel now.  Tank was about half empty.  That seemed to make no difference, but since bucking was not severe I continued on to our destination where my normal RV service center was.  They replaced the filters and it is good for now.  However, we will be here for about 3 weeks and I am sure this is not the end of the problem.  In the meantime, I added some biocide to the tank (sort of like closing the barn door after the horse is out)!

So, what should I expect?  Will driving it and letting the filter take out the furballs work?  I assume the biocide will not "dissolve" them.  I expect to change the filters several times before leaving here in a month.  Is there something to dissolve them?  My first thought was to have the tank pumped out, but not sure that would get all the furballs out!!  How many of them would cling to the tank and surge plates inside?  I will keep the biocide in for now and replace it as I add fuel.

I know there are folks that have been through this before so I would be interested in your feedback on how you handled it and any do's and don'ts you care to share.

Thanks in advance for any feed back!

22 March 2011
12:13 AM
We refueled in Portland, Or at Jubics (sp) truck stop last fall and drove 36 miles before stopping for a month.  After 4 weeks, started the diesel to circulate the fluids and the engine died AFTER a lot of missing and jumping around, ran just a few minutes @ high idle.

Changed the filters and added algaecide to the fuel and started it up again.  Same result.

To make a long saga shorter...
Wound up pumping the tank dry of 90 gals.

In the barrels, it was cloudy and didn't smell like any diesel I've been exposed to.

Tried to start a trash fire and the stuff wouldn't burn.

Drained the tank, then added 20 gallons with Biocide.

Replaced filters and started her up.

Ran just fine.

Waited another week and it ran fine with no residue in the filter sump.

Filled up , added Biocide (and every tank since then) and off we went.

It hurt to lose 90 gallons of fuel, and it burns me to this day.

No damage to the engine due to the excellent filter system.  The junk COULD HAVE blown an injector or three.

I'll not run again without fuel additives.

Just relating our experience...
Good luck.

Stanley P. Miller
22 March 2011
01:17 AM
Biocide is the way to prevent this in the future, just adding a bit of fresh fuel often isn't enough when long term parking in damp areas.

As to the drain or run with the contaminated fuel question it is mostly an issue of how bad the contamination is.  If it is pretty bad, say it is going to foul several of filters you'd want to drain it as the filters are going to get expensive
and be a hassle when traveling.  If it is not so bad and your filters are lasting longer you would probably be better off to just burn the fuel and keep it treated for a while.

If you filled the tank and sloshed the fuel/biocide around pretty good to kill of the stuff growing in there it shouldn't get worse and you might be able to skip adding more biocide when you are using fuel on a regular basis but I'd keep it up for a few months just to be safe.

22 March 2011
01:54 AM
Dumping 90 gallons of fuel is way cheap compared to replacing injectors.
Bill B
22 March 2011
05:56 AM
FYI it shows you to be in central Florida??  Marina's handle this stuff all the time, maybe.  Many of them have external filtration systems that can run / filter your fuel.  Might want to check there?

I've had fuel in steel tanks for several years (farm fuel and heating oil) and not had a problem.  Usually algae requires light and stuff to grow.  Are you sure that you didn't just get a load of ???? fuel?

Friend of mine got some real bad fuel.  They were just filling the tanks and stirred it all up.  His home owners covered the repairs (I know?? but they did). He also had 2 witnesses in the truck with him, receipts, AND 4 - 5 gallons for a backhoe. WATER.  Bill was $5400 and his deductible was $500.

22 March 2011
09:24 AM
I have operated diesel cruising boats in the Florida area for over 20 years.  I had the algae problem only with 250 gals. of diesel fuel.  There are services out there in the marina trade that will "polish" the fuel, which is filtering it until the algae is gone, leaving good diesel fuel.  It is not cheap.  You pay so much per hour and pay for all the filters, and there will be quite a few filters used.  If you are considering just removing and replacing the fuel with new, you'll have a fun time trying to find anyone that will dispose of a large quantity of contaminated diesel fuel.  It is an expensive problem.  I built my own fuel polishing system, but that is too long and detailed to go into here.

At the least if you must use the unit, keep an eye on your filters if they are the see through variety RACOR filters you'll have a better idea when to change them.  You will be changing them often.  By often, I mean daily for a while
or even more depending on the severity of the algae, until the black slime does not show in the filters.  sorry there is no easy fix.

22 March 2011
03:23 PM
Typically, the problem is a bacterial contamination in the oil - not algae.  The bacteria requires water to live - it actually inhabits the interface between the water and diesel fuel.  It feeds on some of the hydrocarbon components
in the fuel, typically the smaller chain hydrocarbons (i.e. cetane).  If left alone long enough it will emulsify the fuel and turn it into a cloudy stinky mess.  Once the fuel gets to this point it is not recoverable by polishing.  Ambient temps of 50 to 80F will also help the little critters grow.

ULSD will not retain water due to its molecular make-up.  So even the smallest amount of water will collect at the bottom of the tank.  I have seen a teaspoon of water support a colony of bacteria.

Once a bacteria colony takes up residence, eviction is pretty difficult.  A biocide and full scale chemical attack are about the only real chances for victory.  This is especially once an infestation has occurred and if the vehicle will sit for a prolonged period of time.

Good luck - PM me or call if you have additional questions.  I have spent a good portion of a 30 year engineering career dealing with these bugs - published a paper, etc.  In a way, the bacteria are kind of fascinating but they can also be very expensive.

Kevin H
22 March 2011
04:02 PM
I've never had an oil burning furnace in my home but don't they burn diesel?  Could the contaminated fuel be burnt in a home furnace?  Perhaps Bob & BJ could sell it to a homeowner to recover a bit of the loss and then it would be
utilized rather than dumped.
Good Luck! -- Kevin
22 March 2011
04:43 PM
Here is an article which pretty much says it all.

Algae, Not the Other White Meat.
22 March 2011
05:28 PM
Thanks for sharing. Good article.

Safe Travels!

22 March 2011
06:24 PM
I had this issue several years ago on my HDT here at the farm, and used the biocide and bought several fuel filters, but we run the truck nearly daily hauling grain, we went thru it pretty quick.  And I kept topping it off with new fuel as well.

Can't say that would work for everyone, but it worked for us at the time.

Stanley P. Miller
23 March 2011
04:03 PM
You'd have similar filter clogging and orifice blocking issues in a furnace and I have no clue how you'd manage to decontaminate the underground diesel tank.
23 March 2011
07:39 PM
Do they still allow the smug pots for use in the citrus fields?  If so perhaps you could sell the fuel to one of the orange growers.  The pots are illegal in California but at one time they were widely used.  Good luck.
23 March 2011
08:08 PM
Smudge pots - haven't heard of them in years.  I earned extra $ in college lighting smudge pots in the groves around Lakeland FL when it got too cold!!

Thanks for the inputs above.  I appreciated the advice.  The article on Algae-X from VeganFlyer seemed to follow on with RWinslow's advice.  I am hoping I caught this before it got too bad.  I am at Patrick AFB in East Central FL for several weeks, but have biocide in the tank at shock levels and will drive it weekly and add new fuel with biocide at shock levels.  Will change filters as needed and keep close eye the issue for several months. When we leave here we will be traveling until Jan when we get to Quartzite for the month and I will certainly use it when we stop for a month!  Will keep the biocide at treatment levels for several months or longer as needed.

If it appears I don't have it under control I will look at the drain or polish options.  When we leave here we will be working our way to RI so there will be opportunities to access the marine businesses along the way.

Thanks again for the inputs.

Greg R
23 March 2011
09:40 PM
I have run my AG gasoline tractors on diesel to save money when diesel was cheaper.  And used to add gasoline to the diesel for anti-gel before the modern fuels.  Av gas was used to dilute the engine oil in aircraft engines in Alaska, thinned the oil.  The gas evaporated when the engine reached op temp.  It works.  Anyway, would gasoline addition help with the contamination problem?  I would like to kill it with another chemical.  One could experiment with one of the replaced filters, in a bucket.  FWIW
Stanley P. Miller
23 March 2011
09:50 PM
The methanol in some gas blends will eat your injector seals, newer diesels are very picky beasts.
24 March 2011
03:29 PM
The biologics that contaminate diesel fuel and other petroleum products digest hydrocarbon molecules.  So, changing the hydrocarbon from diesel to gasoline will probably not make much difference.  The biocides are typically a morholine chemistry derivative and they work quite well. However, the water must be removed to stop the growth and prevent it from returning.

I scanned the article quoted above, with respect to ULSD (Ultra Low Sulfur Diesel) some of the representations in the article are not an issue any more. However, ULSD, if water can get into the system, will support biologic activity.  If you are parked in a warm / high humidity area and do not frequently drive your rig, then a biocide in the fuel is probably prudent preventative maintenance.

Stanley P. Miller
24 March 2011
05:31 PM
Don't just dump biocide in the tank once you are parked either, you want to add it just before your last fill-up so it gets well mixed with the fuel.  You then need to drive a few miles to get it well circulated into your filters and the rest of the fuel system
25 March 2011
05:00 PM
I do have a question I meant to include in my post the other day.  RWinslow brought it up in his first post and again in the most recent one.  Water in the tank; I know there are some products for removing water in gas tanks - typically an alcohol I think. It seems they would work in diesel too.  Will check when I am in auto parts store tomorrow.
Agree with Stanley's comments about mixing the biocide.  I have a filler tube on each side of RV and I split the dose between the two after adding some fuel to roil the fuel in the tank then completed filling.
Stanley P. Miller
26 March 2011
11:15 AM
If you have an IH diesel and add alcohol you may need new O-rings in the injection system, huge expense.  You have to be very careful just what you add to an electronic diesel's fuel supply.
26 March 2011
01:12 PM
There are a number of water removal products for diesel fuel, bio-diesel blends up to B20.

Hydroburn, Power Service 9-1-1, and of course the preferred method_fuel filtration and water separators.

27 March 2011
05:00 AM
This is getting too complex for my simple brain!!  The "fuel filtration & water separators" article was interesting and contained the following quote "Collectively, the result of blending additives and biodiesel into ULSD is deactivation of the fuel-water separator and escape of water into the injection manifold."  The additives reduce surface tension between water and fuel and allow the water to become emulsified and pass through the filters/water separators.  The two additives mentioned by RayIN seem to work like that.

The problem I see is if I leave the water in the tank it continues to promote the algae growth, if I "dissolve" it and it passed thru the water separator it will be detrimental to the fuel injection system.  That leaves the other recommended solution - drain the fuel tank.

For now I am going to monitor the fuel/water separator, drain the cup frequently, and keep the biocide at shock level for several weeks.  While we are FT, we are currently back in home territory for medical appointments and visit family and friends and driving the RV is limited to some short trips (20 mi or so) for some scheduled routine service and maintenance not associated with this issue.  However, I am anxious to get on the road and use up the fuel that is there from our 3 month stay in the Keys!!

Thanks again for the inputs!!

27 March 2011
09:19 AM
I would like to know if you have your tanks turned so that when you start up it sucks what is in the bottom of the tank first. a young fellow in Wisconsin I was talking to him and i don't think he had a high school education explained to me that when you go down the road the sludge is mixing in the fuel so what is the difference if it sucks off the bottom.  Use fuel filters that are water separators they have a knob on bottom to drain the water out.  Since I have done that i never even carry a spare filter start my truck once a week for 15 minutes.  It is not just sitting that
does this as I have a friend that drives full time and has had the algae problem never gave this a thought until the engineer said it was water and you can well bet he had to fill his tanks in the rain and we been blaming the farmers corn for this.  When you don't know enough to know that you don't know you say in my opinion. (IMO)
27 March 2011
01:16 PM
I would have to agree with Stanley that an alcohol based water dispersant type of fuel additive is probably not the best selection for a diesel fuel system.  Hence, I would recommend extreme caution with attempting to emulsify the water and burn it off.

Your fuel tanks may have a small hex head cap screw / bolt on the bottom - mine are a 5/16" hex head.  These can be used to drain the water out of the bottom of the tank, but it is a bit messy.  I have also had luck inserting a small clear plastic tube down into the bottom of the tank, through the filler neck and sucking the water out that way.  However it is helpful to be able to see the water in the bottom of tank through the filler neck.

The most typical method of introducing the water into the fuel tanks is through humid air.  As the tanks are heated by the sun, the air and fuel in the tanks warms up.  When night falls and the temp cools off significantly (i.e. spring time), the fuel in the tank will cool and the warm daytime air in the tank will also cool.  Since the cool night air in the tank is more dense than the daytime air, additional air flows into the tanks through the tank vents (if the tanks were not vented they would collapse due to the partial vacuum).  This night air is loaded with moisture (that is why you have dew on your windshield in the AM) and after several nights of this activity, water will become present in the fuel.  Obviously, the smaller the amount of air that is drawn into the tanks each night, the less moisture introduction opportunity - hence the old advice to keep the fuel tanks full when not in operation.

27 March 2011
03:37 PM
Several years ago I ran out of fuel twice (first was a mistake, second was stupid, but that is another discussion!).  What I found out was that there was about 12+ gals left in the70 gal cross member tank both times.  So I don't think it is sucking fuel from the bottom and there is plenty of "room" for water to lay in the bottom.  So far there has been no visible water in the cup under the water/fuel separator.  My concern with water is it promotes/allows the algae to grow.  The biocide will kill the algae, but as long as water is there it will enhance the return of the algae.

I will look into draining from the bottom of the tank.  Removing 5 gal or so after it has been sitting for awhile would seem to be a good idea/ safeguard.

Thanks again for all the inputs. They do help

30 March 2011
02:39 PM
I took a fuel sample out of the bottom of the water/fuel separator and result was promising.  Only 4 very small dark spots in the approximately one pint sample of fuel.  The dark "spots" were so small as to be barely visible. Probably would have noticed them under normal circumstances!  No visible water.  Still considering draining several gal from bottom of tank but in researching more options I found this info Aquasock info.

I moved the RV to FHU today so fuel is "disturbed" but will not move for another few weeks so will give it time to settle in a few days.  May try it then.

Anyone with water in fuel may be interested in this product.  If I use I will report back!