quote:

Originally posted by jburke:

quote:

the oil level did get 'overfull' even when on diesel.

Thats interesting. I've also read that reported for a couple other non VW TDI DPF equipped cars.
One was really severe.
FWIR overfilling will lead to problems with the catalytic converter.

So...what is one to do if one notices oil "overfilling" between services/oil changes??
Thnx

quote:

Originally posted by mdl3r1:

quote:

Originally posted by jburke:

quote:

the oil level did get 'overfull' even when on diesel.

Thats interesting. I've also read that reported for a couple other non VW TDI DPF equipped cars.
One was really severe.
FWIR overfilling will lead to problems with the catalytic converter.

So...what is one to do if one notices oil "overfilling" between services/oil changes??
Thnx

Personally I'd drain it and change it. Expensive.

Good luck with that guys. I'm going with the science on this one. After seeing the presentation from Chevron (by the way, they just came out with a new oil that is supposed to resist some of the biodiesel dilution better).

As a business, I can't bet my future on the theory that it really does work and that everyone is wrong. As a consumer, if biodiesel doesn't work in these cars, I'll be sticking with 2006 models until they get too old for me, then I'll move on to electric and/or electric hybrids that run on gasoline...

Well I've seen the slideshow presentation by Chevron comparing BD and PD dilution in engine oil and I wasn't that impressed. Where are the hard numbers showing exactly how much of each were in there after a specific run duration? Where are the numbers showing how fast ULSD evaporates out of engine oil compared to BD? Besides which, asking Chevron to compare petrodoiesel to biodiesel is like asking Fidel Castro to compare Communism to Democracy. I only wish I had been present during that sales meeting- "As a representative of big oil I'd like to introduce you all to our revolutionary new miracle fuel! It burns like diesel, lubricates like engine oil, evaporates like water leaving no harmful chemicals behind, and contains virtually no sulfur! Oh and by the way, don't try running biodiesel in these new engines because as you can see in this shiny chart I've prepared, BD doesn't have any of these magic properties."
Talk about snake oil....

Ravenflight, while I appreciate your desire to get to "the truth", you seem to avoid the possibility that the truth may just be that it doesn't work.

I met Gary Parsons from Chevron, and I talked to him in depth about their research.

Here are some facts:

biodiesel has a higher evaporative point than diesel. this means that diesel will evaporate out of the PCV system easier than biodiesel. Exactly how much is unknown to me.

biodiesel is more polar than ZDDP, an anti-wear component of engine oil that sticks to the sides of the engine walls. Because of this, biodiesel replaces ZDDP and you have biodiesel acting as an engine lubricant. Biodiesel is not as good a lubricant, therefore your engine suffers. Exactly how much is unknown to me.

Remember that these big companies do, at a corporate level, want to reduce our use of alternatives and promote the status quo. But when you talk to the *people*, it's not always a cloak and dagger conspiracy. What I took away from the conversations and presentation is that the emissions systems have been pushed to the limit and beyond. Rather than re-engineering the system in a way that we would all have liked them to, they reprogrammed the injectors to squirt fuel into the emissions system. Whether biodiesel is a fine fuel for an engine is not really up for debate - we all know it is. But whether biodiesel is a usable fuel to combust crud in a DPF system that has just been designed without even considering biodiesel as a possible fuel is a whole different question.

You're letting your emotions get in the way of science, and that's just not going to help. A healthy dose of skepticism is one thing, but you're asking for more evidence than I think a reasonable person needs to come to the conclusion that high blends of biodiesel used in a vehicle with a DPF will cause eventual engine problems without non-standard maintenance, in some cases.


One last point by point comment:

"So to recap, the only issue with running biodiesel in my '09 TDI is it gets into the crankcase, same as petrodiesel does, except BD doesn't magically evaporate from engine oil like petrodiesel allegedly does."
Jason - correct, it doesn't evaporate due to a higher evaporative point.

"Except it appears petrodiesel doesn't evaporate that easily either. I can't say I am fully convinced."
Jason - agreed, the data is not in yet on how often or quickly ULSD overfills the engine. BUT, Chevron found that if starting with B5, for example, you wound up with B40 after x number of miles - demonstrating that the percentage of biodiesel in the engine oil is much higher over time (proving that the diesel is evaporating while the biodiesel is not).


"If the 'exhaust gas temperature out of range' was caused by the BD, wouldn't the sensor have picked it up within a few minutes of running your first full tank of BD? Why would the exhaust gas temperature only change after running for 2000 miles on the stuff?"
Jason - the regen cycle only happens periodically, which is when it would check the EGT temp to know if it's ok to push fuel down. They wouldn't want to push fuel in the cold, or you'd wind up with an accumulation of fuel in the DPF. If you put a bunch in there, then got ignition, you could have an explosion. Because of that risk, they are very conservative in when it regens.

"I'm thinking maybe the sensor went out of whack and the dealer mechanic blamed it on your bumper sticker. If my engine oil is going to be contaminated with fuel either way, wouldn't it be better to be contaminated with biodiesel versus petrodiesel?"
Jason - see above discussion about how it is NOT better to have biodiesel in your engine oil due to the strongly "polar" nature of biodiesel.

Of course you're always free to experiment with your own vehicle - and were I not a vendor, I would probably do the same. Since I'm a vendor, I'm not willing to go down that road.


So, what exactly is your position on this issue? I see you shooting down other theories, even calling it snake oil, but I haven't seen exactly what you think is going on. I hope that I've demonstrated more understanding of these issues than you may have realized, and provided a solid basis for at least some of the claims that there is a real problem.

A new article was just published about the oil developed by Chevron that neutralizes the organic acids created by biodiesel in the crankcase.

http://www.biodieselmagazine.c....jsp?article_id=3508

Validates much of what I've been saying, hope it helps everyone understand the issue.

It seems to me there will be a science-based work-around here. That actually works.

quote:

Originally posted by mdl3r1:
Awesome post, Jason! Thanks a bunch for the update!! Indeed, you learned a lot, and so did we, thanks to you! May you be blessed for it all.

Quick question: would a tankful of B100 "here and there" hurt my 2009 Jetta TDI, meaning, would an oil change after a few tankfuls 'restore" and "flush" out the Bio outta the oil crankcase, thus nullifying a short-term slight, perhaps negligible effect?

And, would those occasional tankfuls, or a few gallons into my D2 tank, result for sure in a CEL or even an actual DPF problem?

Or, would, as I hope, a few gallons here and there would not bother anything as long as I go back to D2? I have a friend who brews it and I can see putting it a few gallons added to the D2 I been running since I bought her, or an even more rare b100 tankful, that i would then have D2 tankfuls after?

Thanks in advance..


Miguel

I was reading a article that the injector lines are being recalled due to cracking on this generation of TDI cars,2009 etc Could this be a source of Oil contamination ???? Only an engine that is not broke in properly or badly worn out should have enough raw fuel getting past the rings to cause enough noticable accumulation of fuel in the crankcase.

quote:

CEL

I had my CEL light up and took it for a test at the local VW shop. The first thing they said was you were running biodiesel ( I wasn't). It was the middle of winter and I hadn't run bio since the last tune up and oil change. After the $150 test, they told me it was my EGR valve was dirty and it would cost $600 to fix. I said thanks, but I would wait until it failed constantly. It went away once I started following the start up procedures in the manual exactly, weird. So now, I put my foot on the brake, turn the key on, wait for the glow plug light to go off and start. No problem. I am running 75 - 100% biodiesel. I do change my oil every 5K, just in case.