DieselGreen Fuels tests B100 in 2009 Jetta TDI

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Neurot

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shizzler, don't bother. vwrobert is not interested in it working. he's just injecting sarcasm and negativity, and waiting for a failure.

if VW had documented any real testing with high blend biodiesel, and any possible check engine lights or actual problems, we wouldn't be having this discussion - we would just be consulting the literature.

I left a message with the dealer today to bring it in and have it checked. I'll report back what happens.
 

rotarykid

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Neurot said:
shizzler, don't bother. vwrobert is not interested in it working. he's just injecting sarcasm and negativity, and waiting for a failure.

if VW had documented any real testing with high blend biodiesel, and any possible check engine lights or actual problems, we wouldn't be having this discussion - we would just be consulting the literature.

I left a message with the dealer today to bring it in and have it checked. I'll report back what happens.
I would be willing to bet that VWAG has documented the failures they expect from high % of BD use .

I'm also betting they , VW of America are monitoring this board on this issue to protect themselves from warranty abuse .

BD is higher Cetane but has less energy so it's likely that the system is either seeing an overheat or an under heat during regeneration . If memory serves higher Cetane means less delay in ignition and a more predictable ignition pulse .
 

Neurot

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I sure hope they are monitoring this to protect their customers from being abused by their dealers.

You are correct that B100 has higher cetane but lower BTU content than diesel. It will be interesting to see what data the dealer can pull from the system to find out what happened exactly. I do agree that it is probably an over or under temp due to the slightly different characteristics of B100 from diesel. If it's really far out of the range needed for regen (assuming that's the issue), it could mean that B100 won't be usable by most people without a workaround to invoke regen manually. Although that wouldn't be what I want to hear, it's exactly the data I'm looking for and validates the purpose of the testing.
 

shizzler

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Duh, cetane. Good call. Faster ignition during a post injection would most likely cause combustion to end sooner, thereby releasing more heat in cylinder and leaving less for exhaust temps. Thereby causing a low temp fault from the sensor. Less BTU's also would lower EGTs at the same A/F ratio.

BUT: Could the difference in cetane really account for EGTs different enough to trigger a fault code? Regular pump diesel can vary too. But we're talking a 40 cetane # vs what, 55 for bio? So maybe. This experiment is enhancing my knowledge of combustion, thanks Neurot.

If this is the problem, than it may happen every regen cycle. I don't see a workaround beyond ECU programming for addtn'l fuel in regen process, or altered injection timing of the post injection. Good luck with that. On the other hand, if the regen is triggered by mileage, it may not be a problem at all and you simply need to clear the codes and keep on truckin. (let's hope)
 

RI_TDI

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What condition(s) ordinarily trigger a regen? Will VAG-COM provide trending of the temperature in question?
 

jvance

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shizzler said:
Duh, cetane. Good call. Faster ignition during a post injection would most likely cause combustion to end sooner, thereby releasing more heat in cylinder and leaving less for exhaust temps. Thereby causing a low temp fault from the sensor. Less BTU's also would lower EGTs at the same A/F ratio.

BUT: Could the difference in cetane really account for EGTs different enough to trigger a fault code? Regular pump diesel can vary too. But we're talking a 40 cetane # vs what, 55 for bio? So maybe. This experiment is enhancing my knowledge of combustion, thanks Neurot.

If this is the problem, than it may happen every regen cycle. I don't see a workaround beyond ECU programming for addtn'l fuel in regen process, or altered injection timing of the post injection. Good luck with that. On the other hand, if the regen is triggered by mileage, it may not be a problem at all and you simply need to clear the codes and keep on truckin. (let's hope)
Also, the "balance point" for particulate deposit in the DPF occurs at over 100C lower temperature that the balance point for regular diesel. So even if the exhaust temperature is below tolerance for regular diesel regen, it might be fine for B100 regen.

"Balance point" of course being the point at which particulate burnoff rate matches the particulate deposit rate.
 

GoFaster

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... problem being that the engine controls won't have any idea that this is the case.

If it wants temperature "X" and doesn't acheve it, then it's probably recorded as a failure. But, again, we don't know how the programming works. At this point, it could be a plain ordinary bad sensor that would have done this no matter the fuel. That has happened before ...
 

green-gas

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If I were to guess, my bet would be undertemp during regen.

Based on some light reading I did, I think the concern comes from the difference in flashpoint between diesel & biodiesel.

With the (much) higher flashpoint of B100, maybe the B100 is not being burned-off during the regen (also where the potential oil contamination issue may come from).

If the B100 is not burning off, that would definatly make for a cooler exhaust temp, and possibly make the regen not work?

Anyone know if the exhaust needs to hit a certain temp for a successful regen? - maybe that is what is being reported...
 

kcfoxie

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IIRC some PDs had Biodiesel sensors that adjusted timing to make better use of the fuel, these were euro models.

Seems that applying the same sensors to this design could adjust the necessary parameters to the exhaust regen system, thus making the car "flexible fuel" friendly.

But I'm wishfully thinking :)
 

GoFaster

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green-gas said:
If I were to guess, my bet would be undertemp during regen.

Based on some light reading I did, I think the concern comes from the difference in flashpoint between diesel & biodiesel.

With the (much) higher flashpoint of B100, maybe the B100 is not being burned-off during the regen (also where the potential oil contamination issue may come from).

If the B100 is not burning off, that would definatly make for a cooler exhaust temp, and possibly make the regen not work?

Anyone know if the exhaust needs to hit a certain temp for a successful regen? - maybe that is what is being reported...
This is a valid hypothesis. The other one is that the EGT sensor is just plain bad or out of spec. At this point it's a wait-and-see ...
 

Lightflyer1

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I have offered my VCDS cable and laptop (805.1 version) to assist Jason if needed. Are there any tests/scans that may prove beneficial to him in this endeavor?
 

Neurot

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and by the way, I have an appointment with the dealer on Friday for service on this issue. I don't want to clear any codes, but if there is any other data we could obtain in the meantime, let me know.
 

Lightflyer1

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We can run a basic scan without clearing any codes just as a baseline before it goes to the dealer. I may be making a trip into Austin this evening around Lamar and 45th street. If you are around there I could stop by with the laptop. I'll be in my 1935 Ford though and not the A5.
 

Neurot

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We have an open house every Tuesday night from 7-10pm at our shop at 5217 Cesar Chavez St. Up until 6:15 or so, I'll be at home, which is at 38th and I-35. Feel free to give me a call if you can stop by, it would be appreciated!
 

MBoni

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Neurot said:
I do agree that it is probably an over or under temp due to the slightly different characteristics of B100 from diesel. If it's really far out of the range needed for regen (assuming that's the issue), it could mean that B100 won't be usable by most people without a workaround to invoke regen manually.
Hmm, would this line of thinking mean that you didn't have a regen event until the car hit 1380 miles? That's a pretty good interval.
 

GoFaster

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I have seen tech papers that VW published about this system, and they expect a regen event approximately every 1500 km (but this will vary depending on operating conditions), so it's not outside the realm of possibility that this was the first or second regen event.
 

cessna

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I hope somebody will test a 50/50 blend of bio and D2. That's what I try to run in my 2006.
 

conejo_a_cuatro

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Hmmm, if this turns out to be something serious, I wonder if Urea injected cars would be more or less amenable to B99. Here's hoping an Italian tune up gets the job done!
 

maktas

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Neurot said:
and by the way, I have an appointment with the dealer on Friday for service on this issue. I don't want to clear any codes, but if there is any other data we could obtain in the meantime, let me know.
I hope they don't know about this experiment..... :) Good luck and we are all hoping its something unrelated to bio-d
 

Fencemaker

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Guys - go back and read Jason's first post. He was quite clear in his position that - no matter what VW has been telling the public about greater than B5 voiding the warranty - he believes that VW cannot legally disclaim warranty coverage under the Mag-Moss Warranty Act simply b/c he used biodiesel. I believe Jason's position is that unless VW can show that the biodiesel actually caused a particular failure, they cannot refuse to honor their warranty for a failure. So, if he has an EGT sensor that is out-of-whack for a reason wholly unrelated to biodiesel use, he expects VW to cover it or be on the receiving end of his lawsuit.

Jason - if I've got your position wrong, please correct me.

By the way, I'm not endorsing or rejecting Jason's position and am not giving anyone legal advice here. Just restating what I understand Jason's position to be, so that everyone can stop trying to tell him that he better fill the tank with D2, or lie to the dealer, or whatever to cover up his B100 use.
 

kcfoxie

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A D2 fill won't matter. After 7k miles of D2, I still smell the hint of methyl esters when i pop my filler cap.
 
Joined
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Baltimore
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You can smell ME's? Could you describe the smell for me, I really don't smell it, I don't think.
I know what kind of ass D2 smells like, can't believe you can make out *anything* in that kind of environment...
thx
 
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