Biodiesel sludge v2.0: The saga continues!

For those of you joining this story already in progress, here are links to the story as it unfolded:

Biodiesel sludge v1.0:
http://forums.tdiclub.com/NonCGI/ultimatebb.php?ubb=get_topic;f=5;t=005194

Suction strainer help:
http://forums.tdiclub.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=5&t=005219&p=

Fuel Temp sensor fault code:

http://forums.tdiclub.com/NonCGI/ultimatebb.php?ubb=get_topic;f=3;t=008764

And now the latest:

I finally got a tool (not the proper one by any stretch, but it worked with only a small amount of bloodshed) to unscrew the large retaining nut that holds the suction strainer/return and the fuel tank level switch in place.

Here's what I found (these pictures may not be suitable for all biodiesel fans ) (descriptions ABOVE respective pictures)

First, the lower contents of the suction strainer assembly:


This is what came out of the top section of the strainer (ie it was floating on the stuff on the bottom:


This is the residue on the bottom of the strainer cup after the sludge was poured off. Notice the rust colored flecks... still as yet unidentified.



The fuel gage sensor/sender... again, notice the milky/chalky residue in the nooks and crannies and the color of the fine residue.



[ September 23, 2002, 15:44: Message edited by: MITBeta ]

Continued:

Here's what the remainder of the fuel in the tank looked like after two fill ups with (gasp) petrodiesel.



The two main sections of the suction strainer assembly, minus the fuel level sensor.



That ain't Arizona Iced Tea:



Lastly, this stuff plugged up my strainer:



After disassembling this whole unit, I used fresh biodiesel (well, what would you use?) to thoroughly clean all the surfaces of all the pieces. Then I pumped out what was left in the fuel tank (about a gallon) as sopped up the remainder with paper towels.

I then removed my fuel filter and turned it over, and sure enough the rusty flecks were still present in the filter. So I changed that as well.

I reassembled the whole business and filled (vented of course) with FRESH biodiesel. The car purred to life.

So, I'm fairly pleased with the results of 2.5 hours of work yesterday afternoon, and after I receive the biocide that RC sent, I'll be 99.9% confident again in the reliability of my car.

DBW has given me instructions on how to replace the fuel temperature sensor in the fuel pump, so that's a job for later in the week.

Oh, the joys of biodiesel usage! But important lesson learned: Don't store bottom of the barrel (literally) biodiesel in a hot shed for 2 months and then dump it into your fuel tank without first inspecting it.

Great pics Phil. I am anxious to find out just what that stuff is. What does it smell like? Did you save some to experiment with? Biocide will be at your door in a few days.

Hey Joe Rappa, what`s your take on this?

Phil, I just have to tell you how much your experience has strengthened my resolve to use only biodiesel in my car.

Look at the advantages: It's easy to find, works flawlessly, and teaches you how to fix your engine. Plus, it gels up in Winter. Wow! Gimme gimme.

Phil, that looks just like the Thousand Island dressing I had on my salad this evening. Sure doesn't look like any BD I have ever seen.

How do you know this isn't a result of water contamination?

Maybe if he's willing you can send a sample to GeWilli to do a spectoscopic analysis!

Phil, what sort of stuff was in the very bottom of the tank after you got all the fuel drained out? Anything that would raise eyebrows?

RC, where do you get your biocide?

MITBeta (and others) - with regards to a discussion we had been having previously about winter use of biodiesel, I had another thought.

Since our engines circulate some warmed fuel back to the tank, once the engine is up to operational temp, there shouldn't be a problem, so the main concern is just being able to start the car. So, how would something like the inline "VEG-therm" fuel heater work? It is designed to heat vegetable oil to 70C (I'm assuming we could instead use it to heat to just say 15-20C) just before entering the engine. It's basically just a big resistor, using the alternator/battery to heat up really quickly, with the fuel passing through it.

I'm thinking that it could also be turned on remotely, say while approaching the car, so it has 10-15 seconds or so to start warming up before I get to the car, which might be enough time to get the fuel nice and fluid to get the engine started. If it could be set to keep the fuel at a certain temperature, say 20C (or higher), then once the engine gets up to operating temp (so the fuel in the tank is being warmed beyond 20C) the VEG-therm would just shut off.

So - do you guys think an inline heater like that would be enough to safely get the engine started on 100% biodiesel? Or would there be problems with having residual gelled biodiesel in the engine itself, on the fuel injectors, etc.

How do you know this isn't a result of water contamination?

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<font size="2" face="Verdana, Helvetica, sans-serif">I don't. I still don't know what, exactly, caused this.

MWG: I can't tell how sarcastic you're being here, so I'll just assume the worst:

Let me make mistakes (ie gain experience/wisdom) so that you and all the other biodiesel wannabees don't have to. Nothing about this situation has been anywhere near too difficult to handle, and my position on biodiesel has not changed in the slightest. If anything, I'm more resolved to use it since I know that I can pretty much handle any unfortunate consequenses that result from doing so.

And you're certainly right about one thing: I've learned A LOT about how my fuel system works in the last two weeks. Also, I'm happy to say that my wife can now change a fuel filter, which gives me one less thing to worry about during the day.

I can't wait to get some biodiesel into our new Passat Wagon

what sort of stuff was in the very bottom of the tank after you got all the fuel drained out? Anything that would raise eyebrows?

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<font size="2" face="Verdana, Helvetica, sans-serif">Surprisingly, no. It seems as though all the bad stuff got trapped in either my (ahem) 3 fuel filters in 2 weeks, or the suction strainer assembly.

Mike: I've thought about this too, however you have to consider that the warm fuel flow back from the fuel return line (the blue one in the pictures above) is something on the order of 5-6 gallons per hour at idle, and probably not much different at load. I don't think that's enough heat to ungel any fuel that has actually gelled. Instead you'll probably be able to go a few miles AND then stall.

What does it smell like? Did you save some to experiment with?

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<font size="2" face="Verdana, Helvetica, sans-serif">Smells like biodiesel. I have what you see in that Arizona bottle available for anyone who wants to take a crack at molecularly dismantling this ooze.

I also still have the stuff that originally came out of my fuel filter, as well as a sample of biodiesel that was in the tank BEFORE I diluted with petrodiesel. This fuel, interestingly enough, has undergone NO separation of any kind after sitting on my kitchen counter for a little over a week. (My wife loves all my little science projects )

How could you reach into the nooks and crannies of the tank to mop it all up?

MWG, Phil is right. No reason to break his b*lls over this. He has worked thru it scientifically to get his car back on the road. He also is much more proficient under the hood now and elsewhere on his car which is more than I can say for others I know.
.
.
.
(Can I say b*lls or is that against the new rules )

How could you reach into the nooks and crannies of the tank to mop it all up?

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<font size="2" face="Verdana, Helvetica, sans-serif">Well, it's pretty smooth inside, and I did the best I could. I didn't find any goop in the areas near the opening, so I'm guessing (ie praying) that there wasn't any in the furthest reaches from the hole.

Dorf: I think you can say b*lls, but not balls.

One other interesting thing: I noticed that after doing all this work that my fuel gage STILL doesn't go up as far as it used to. It still reads above the F mark when vented full, but does not reach as far into the 1/1 zone as it used to. Did I read that there was a way to calibrate this via VAG-COM?

Originally posted by MITBeta:

Dorf: I think you can say b*lls, but not balls.

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OIC !

Yes. It's in the Bentley CD.

That's rough, and is more than a little frightening.

You'll have to teach me how to re-prime the fuel filter sometime so I can do it myself.

Mike: I've thought about this too, however you have to consider that the warm fuel flow back from the fuel return line (the blue one in the pictures above) is something on the order of 5-6 gallons per hour at idle, and probably not much different at load. I don't think that's enough heat to ungel any fuel that has actually gelled. Instead you'll probably be able to go a few miles AND then stall.

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<font size="2" face="Verdana, Helvetica, sans-serif">Hmmmm... good point.... how about this - one of those heaters just before the fuel enters the engine, and one on the return line to the tank, just next to the tank (set to hold the temp at 70C)? Since it isn't a large amount of fuel returning to the tank, just superheat the small amount of fuel that does return so it's really hot.

It would of course be better to have a heater right in the tank, but that would be more difficult. The easiest way to do that that I can think of would be to run a tube of coolant along the fuel line, back to the tank, and around inside the tank. But it would be so much easier to just put a couple inline heaters on the fuel lines somewhere.

[ September 23, 2002, 17:50: Message edited by: nh mike ]

Well, pretty damned sarcastic, but not meaning anything personally. I apologize if I offended. But I sure have unanswered questions and worries about biodiesel.

Originally posted by MITBeta:

MWG: I can't tell how sarcastic you're being here, so I'll just assume the worst...

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MITBeta,

It could be very well emulsified water & fuel.

I did an experiment with about a pint of fuel and some additive that claimed to be an emulsifier. It was and a very good one at that!!! I had a straight unadditized control fuel sample and the additized fuel test specimen. Added water to both, shook them up and let them sit. The one with the additive looked like your stuff, a little thinner though, and the water fell right out of the non-additized fuel. The emulsified one stayed like that for months.

I've been doing some research lately into polishing filtration. I'm looking into adding a 2 micron filter to my car. Not too easy, not too much room. In talking to one particular company, that I can't recall right now, they said that when dealing with biodiesel, it is very important to keep it dry, far more so than petro diesel. Per their testing!

Keeping the fuel dry is one of the most important things to do to prevent/minimize microbial blooming.

Check out the filtration page at Stanadyne's web page. They have some very impressive water desiccant performance graphs on their 2 & 5 micron filters.

And it should be real easy for you to get biocide. Go to any diesel shop or marina. You should have a marina or two nearby. Boats have big microbial growth problems and use biocide regularly. BioBar (sic?) is another popular fuel biocide used widely in the marine application. I was just at my local Bosch shop checking out the Stanadyne filter units and they had Stanadyne(?) and Racor biocide.

Maybe with the addition of the new wagon, you'll be turning over your fuel cache quicker!

I still think you should give the manufacturer a call. If something is amiss, they will be in an ideal position to help us understand what it was and how to avoid it in the future. Perhaps a bad batch was made somewhere. I have sent beer back twice in my life and, even if they pitched them, I ended up with hats and a few cases of German lager to ease my jilted palate.

Burke is just a reseller. Call WE.

Um, is this homebrew?

If not, is there a reason you do not want to contact the manufacturer?

Are we absolutely sure this "stuff" in your tank is remnants of the "bad" fuel? Could it be the B100 is eating something that is ending up spread throughout your fuel system...?

Betzel:

Nate and I have contacted Burke and WE.

Ed:

I really don't think the biodiesel is eating anything. The rust colored residue is identical to the stuff I found in my Blitz jug. Garbage in, garbage out.

Boundless and all, do we know for certain that biocide for diesel fuel will be effective as a “quick-kill” for biodiesel as well?

dieseldorf,

I have no idea if the bugs that prefer BD are the same bugs that prefer petroD. I do not know if the biocide is that well targetted to certain species. I don't think so. I think BD might be more palatable than petroD, to the bugs that is.

But, here is something to think about. If I remember my high school biology, water is required for life. (This was also contained in numerous articles I have recently read regarding fuel filtration.) The bugs that cause these fuel problems need the water to live in and on, and the fuel is the nutrient. Those bugs eat the fuel, metabolize the fuel into more water and other by-products, multiply, Presto! Microbial bloom = fuel scuz.

I would venture a guess that the bugs causing these problems are the same regardless of fuel. The bugs are carried by the environment and into fuel. The bugs come in with the water and air, so it should be the same bugs regardless of the fuel. If it's the same bugs, the same biocide should apply.

In the complete absence of water, the bugs that cause these problems should not be able to live, thrive or multiply.

So, my opinion, given the above, is that the bugs are the same regardless of fuel and the same biocide should be applicable.

Diesel fuel biocides are readily available at diesel shops and boating/marina supply stores.

Water in fuel is bad not just because it causes rust and destroys lubrication. Water is also very bad because it enables the environment necessary to support microbial life.

I would guess that MITBeta had high water content and/or the fuel has sat around too long allowing a microbial bloom.

the bugs are all different, so are the drugs used to inhibit their growth.

Ahhh, the doctor is in. Thank you, SkyPup. That was my concern and suspicion.

The same holds true for the anti-gel scenario. Anti-gel additives used on petro diesel don't work for bioDiesel and vice versa.

Originally posted by SkyPup:
the bugs are all different, so are the drugs used to inhibit their growth.

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<font size="2" face="Verdana, Helvetica, sans-serif">And does that mean that the common biocides such as Racor, Stanadyne, BioBor, PowerService, etc. will or won't work with biodiesel?

[ September 24, 2002, 08:58: Message edited by: Boundless ]

But I sure have unanswered questions and worries about biodiesel.

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<font size="2" face="Verdana, Helvetica, sans-serif">Please, tell us what they are. If one HAS all the answers to all the questions about a particular subject, then there is no use in delaying the making of a decision to do something as it relates to the known information.

If one does not have all the answers, one needs to ask more questions.

MIT,

Perhaps a little experiment with that salad dressing like stuff you pulled out of your tank.

Stanadyne Performance Formula contains a demulsifier. If you were to add some to the dressing and mix it up, perhaps the dressing will seperate. That will/might tell you if there is water. If the demulsifier works on BD.

If it's not water or bio, there is something else going on here.

Also, I checked with a couple fuel biocide producers to see if their biocide works with BD. Oh, I don't think Stanadyne makes a biocide anymore. Racor and PowerService confirmed that their biocide products will work with biodiesel. Hammonds (BioBor) is checking. All of these are readily available at many types of stores.

The Racor rep explained that the biocide acts as a poison in the fuel. Since the fuel is the nutrient, when the microbes living in the water consume the fuel, they are also consuming the poison. Dead bugs. Racor went on to explain the microbes are water and air borne and get into the fuel with water to cause the problems.

You might want to call these biocide companies yourself and see what they might know to help you out.

Good luck!

PS: I'll driving by the Sagamore Bridge circle around 5 PM on Saturday. I'll wave as I go by!

[ September 24, 2002, 14:31: Message edited by: Boundless ]