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New Mickey

The user formerly known as mickey
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I used to play with biodiesel, and studied up on the pros and cons, but there is one issue that never occurred to me...and which VW mentions in the 2015 owner's manual: Biodiesel has very low volatility, so fuel that gets into the motor oil as a result of normal blow-by tends to stay there, and dilutes the oil. They strongly recommend against using biodiesel in ANY quantity.

If this is really a problem it would apply to any engine, not just the "newest" ones. In fact, older engines would have more blow-by.

Thoughts? It sounds like a legitimate concern on the face of it.

-mickey
 

Geordi

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"sounds like a legitimate concern" and "is a...." are two entirely different things.

I ran homebrew B100 for over a year and more than 1000 gallons in my first TDI. Never once had an issue with the oil level changing or the oil being "diluted" or anything else.

Volatility does NOT equal burnable in a diesel, diesel is also very low VOC yet it burns just fine. Neither one will light (easily) with a match unless there is another surface involved, like a paper towel that becomes the "wick" and supports the combustion. Yet they both burn JUST GREAT under pressure and heat of the compression ratio. If it didn't, you wouldn't have any vroom at all from pure or high ratio biodiesel mixes.

The buyer of my car did have a comment about the car - he wanted to know what I had done to it, and why it was so damm fast. Bio: It keeps your engine young.
 

JSWTDI09

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If this is really a problem it would apply to any engine, not just the "newest" ones. In fact, older engines would have more blow-by.

Thoughts? It sounds like a legitimate concern on the face of it.
Things often go deeper than the face of it. The problem with biodiesel in modern diesel engines has to do with DPF regeneration. Bio contaminating the engine oil was never an issue with older diesels because the fuel was always burned. In modern diesels fuel is occasionally injected into the cylinder during the exhaust stroke to pump raw fuel into the DOC (Diesel Oxidation Catalyst) which, in turn, begins the burning off of the soot trapped in your DPF. Some of this fuel (un-burned in the engine) gets past the rings and enters the engine oil. Then the volatility issue you mentioned comes into play.

If our cars did not have this complex (read: expensive) emissions system, biodiesel contamination of engine oil would not be a problem. Welcome the world of modern diesel emissions control systems.

Have Fun!

Don
 

New Mickey

The user formerly known as mickey
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Utah
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I ran some B-100 in the Evil Beetle back in the day and didn't have any problems.

Indeed the DPF regeneration is probably the culprit, though if that causes a problem with biodiesel then the problem also exists to a lesser extent if you don't have regeneration. My guess is that you COULD run into trouble if your diesel is frequently used for short trips and doesn't get to run at full temperature for long periods. Which, of course, means you bought the wrong vehicle. DPF regen. just amplifies the issue.

-mickey
 

atc98002

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2014 Passat TDI SEL Premium (sold back), 2009 Jetta (sold back), 80 Rabbit diesel (long gone)
There are two issues with BioD and the CR TDI engines. One is as mentioned here, that the DPF regeneration cycle dumps raw fuel into the cylinder and some makes its way into the oil pan. It doesn't readily evaporate from the pan, so you end up with a) diluted oil and b) excessive amount of fluid in the pan. The other is the temperatures that are reached in the injector, and the inability of BioD to tolerate such temperatures. DBW has shown some pictures of a CR injector after running BioD, and it's not a pretty sight. That and it renders the injectors ruined and require replacement.

The non-CR TDIs don't have either of these problems, and is why many people have used BioD for years with no issues. I used it on an old Mitsubishi IDI diesel engine, and my wife said the exhaust actually had a reasonable smell to it, opposed to normal D2. And of course my 2014 Passat had virtually no exhaust odor at all. The urea added just a touch of "something", but it wasn't at all objectionable.
 

2015vwgolfdiesel

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Oklahoma
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2015 VW Golf S DSG Silver
I used to play with biodiesel, and studied up on the pros and cons, but there is one issue that never occurred to me...and which VW mentions in the 2015 owner's manual: Biodiesel has very low volatility, so fuel that gets into the motor oil as a result of normal blow-by tends to stay there, and dilutes the oil. They strongly recommend against using biodiesel in ANY quantity.

If this is really a problem it would apply to any engine, not just the "newest" ones. In fact, older engines would have more blow-by.

Thoughts? It sounds like a legitimate concern on the face of it.

-mickey
Where in your (MY) manual can I read about this issue.

Sad to heard this.

Personally blame the "greenies" up and down the line for BIO junk in both diecel and gas.

Wife used 100% gas in her 2015 RAV4. Hate to fill up in Tulsa with any BIO in my car. As far as I understand there is no BIO free fuel in Tulsa. Grrrrrr.:mad:
 

philngrayce

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I think VW wants 100% diesel, but some states mandate a percentage of bio, so the manufacturers have to allow it.

When we ran WVO (in somewhat older tdis) we always shortened the oil change interval. This would probably be a good idea if you are running biodiesel in a new VW.
 

2015vwgolfdiesel

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2015 VW Golf S DSG Silver
I think VW wants 100% diesel, but some states mandate a percentage of bio, so the manufacturers have to allow it.

When we ran WVO (in somewhat older tdis) we always shortened the oil change interval. This would probably be a good idea if you are running biodiesel in a new VW.
Thanks for your response. :)
 

Drivbiwire

Zehntes Jahr der Veteran
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2013 Passat TDI, Newmar Ventana 8.3L ISC 3945, 2016 E250 BT, 2000 Jetta TDI
Heat Biodiesel to 400-600F and see what happens...Thats the operating temperature inside the injectors, High Pressure fuel pump, Head passages, Injector nozzles, high pressure plunger and other injection areas of the fuel system.

After you heat it and hold it at that temperature, note the amount of varnish, Gums, Deposits, Residues and solids that form in your sample.

Fuel is used as a COOLING MEDIUM to keep the fuel system operating at high temperature and extreme pressure within limits.

Fuel is routed back to the tank and this is your heat sink, and method of "Cooling" for the system. Most new CR and PD engines have the belly mounted radiator to further increase cooling of the fuel.

Biodiesel fails because it is unstable when heated above 240F, and there is no way you can keep fuel within those temperature ranges while circulating within the ultra precise regions of your fuel system.

5% is generous, and only because ULSD/#2 fuel dilutes the quantity of the sludge that forms within the confines of the systems.

Biodiesel = FAIL in all newer engines.

 
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2015vwgolfdiesel

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For a good look at the issues with bio D take a look at:



https://umexpert.um.edu.my/file/publication/00006641_89203.pdf



Other than the fact that it produces sludge in the fuel system, plugs the DPF, and dilutes the lubricating oil, it also forms more coke deposits on injector nozzles... great stuff.


Greens are killing our cars with every drop of bio. :mad:

Betcha VW is not thrilled with the 11 year, 162,000 miles warranty on their FIX cars

I've searched Tulsa for 100% Diesel. No luck yet.
 

New Mickey

The user formerly known as mickey
Joined
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Location
Utah
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2015 Passat
I've never seen BD5 anywhere around here unless I got to a supplier and buy it. If you want to play with it I do suggest buying an old Mercedes. They'll eat anything remotely flammable. Even straight vegetable oil.

-mickey
 

2015vwgolfdiesel

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Oklahoma
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2015 VW Golf S DSG Silver
Maybe this article could give us more info to enlighten our confusion/s about bio D: http://auto.howstuffworks.com/fuel-efficiency/alternative-fuels/biodiesel4.htm
_____________________________________________________
tow truck st louis
Quote from the post

________________

there can be slight decrease in fuel economy and power. On average, there is about a 10 percent reduction in power. In other words, it takes about 1.1 gallons of biodiesel to equal 1 gallon of standard diesel.

__________________

What the hay? -- I smell a tree hugger
 

mrseadog

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There are a number of things that should be taken into account when using biodiesel (which I don't) or vegetable oil (which I do). Shortened maintenance schedules is just one of them. If done properly those alternative fuels can be used successfully.
 

Drivbiwire

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There are a number of things that should be taken into account when using biodiesel (which I don't) or vegetable oil (which I do). Shortened maintenance schedules is just one of them. If done properly those alternative fuels can be used successfully.
How do you propose reducing the injection systems operating temperatures by 600F so you can safely do that?

The engines have long ago exceeded the limits of unstable "Gen 1" bio fuels, only Gen 2 Biofuels (GTL, FT etc) can comply with the extremely high temperatures of the fuel systems in modern cars.

Unless you are talking about a 1980's IDI engine, the fuel is failing from mile #1 its used.
 

philngrayce

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Those 80's cars do seem to be very tolerant of any type of fuel. But I have quite successfully run an '02 and an '06 TDI on vegetable oil with a dual tank system. In addition to the shortened oil change intervals, the car should be fully warmed up on diesel, the vegetable oil should be hot, and the oil should be thoroughly purged from the system before shutting down. It's aslo nice to have really clean oil.

Others have suggested additional things, including modified injectors and electrical or programing changes. Some won't even use WVO in slow traffic or city driving. I have not found these necessary.

I do believe the newest cars would be much more problematic to convert. But then, that was what they said about the '02 and the '06 too.

All that said, there are some who have had problems, and it is a pretty major change, so I hesitate to recommend it. Buyer beware.
 

mrseadog

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Location
St. Louis, MO
TDI
2002 Jetta
How do you propose reducing the injection systems operating temperatures by 600F so you can safely do that?
I don't propose to do anything as I see no reason to. Philngrayce in the post above said it quite well.

I have been doing this for nearly 10 years using a 2 tank system and have driven over 250,000 miles. The money saved on fuel easily covers the shortened maintenance schedules. It takes some effort to do it but as I stated in my original post if done properly, these alternative fuels can be used successfully.
 

atc98002

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All of the anecdotal comments about successfully burning either WVO or bioDiesel are not referring to the CR engines. The current, Common Rail engines will not last when using BioD or VO. As DBW has commented, the temperature at the injector is far too high for any Gen 1 bio fuel to work for long. When the CR engine first came out, several people have attempted to use various levels of BioD. Anything above 20% was causing issues and triggering the CEL. While 20% and lower "appeared" to work, injectors inspected after use still shows damage. And oil changes are required far more frequently. With the CR engine, you have to stick with straight D2 or one of the few Gen 2 fuels that appear to the engine as D2. Propel HPR is one such fuel, but isn't widely available.
 

philngrayce

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'02 Jetta, '06 Jetta, Both Gone '13 Leaf, Gone Liberty CRD, Subaru Forrester and MB300SD
I was responding to the statement about failing unless you are talking about 1980's IDI engines. That seems not to be accurate.

It probably is true that the newest engines won't work, and i said so. But that might be wrong too. I'm not aware of anyone trying it long term. Or maybe they just haven't figured out how yet.
 

mrseadog

Active member
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What he (Philngrayce) said. Note the car in my profile. I don't have a CR and therefore can not comment on that engine. FWIW, I don't consider my experience anecdotal.
 

atc98002

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I agree that engines prior to the CR often had success with WVO/BoiD without issue. I only threw in the comments about the CR because the OP was talking about a CR engine, and the comments were moving between IDI, TDI and CR. Simply wanted to ensure everyone is on the same page.

In my state, D2 isn't required to be labeled with a BioD % if it is 5% or less, although every pump I remember still had a sticker that stated that it contained some BD. When I had my Mitsu Pickup, I ran B100, but of course that was an IDI. I'm waiting to see how soon Mazda or Chevrolet releases their diesel CX-5/Equinox, because I really want a diesel again and I doubt VW is going to bring them back.
 

philngrayce

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My brother bought one of the "new old" VW Jettas a month or two ago. The price is good, the warranty is extraordinary and the car runs great. You might want to consider one of them if the dealers still have them.
 

atc98002

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If I was going to stick with a sedan, I would have kept my Passat. I liked it a lot. But I wanted to go back to a CUV/SUV for the higher seating position. Getting hard to get into and out of a sedan as I get older. :p

Also, I want some of the latest safety features, in particular Adaptive Cruise.
 

New Mickey

The user formerly known as mickey
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Location
Utah
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2015 Passat
If I was going to stick with a sedan, I would have kept my Passat. I liked it a lot. But I wanted to go back to a CUV/SUV for the higher seating position. Getting hard to get into and out of a sedan as I get older. :p
Also, I want some of the latest safety features, in particular Adaptive Cruise.
My daughter the airhead has a 2017 Passat Tsi. The base model. But it has radar-based collision avoidance, and it has already saved her bacon.

I don't know what the real story is, but I suspect very strongly she wasn't paying attention. (She says otherwise.) But whatever the case she was shocked when the car suddenly slammed on the brakes all by itself and STOPPED at a red light before she could hit the car in front of her. Got into the anti-locks and everything.

I don't know how important the adaptive cruise control thing is, but the anti-collision technology is the real deal. And of course if you have THAT there is no real excuse not to have adaptive cruise control. It's just software at that point. They only put it in the high-end trim levels because it's an excuse to charge more money.

-mickey
 

2015vwgolfdiesel

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My daughter the airhead has a 2017 Passat Tsi. The base model. But it has radar-based collision avoidance, and it has already saved her bacon.


I don't know what the real story is, but I suspect very strongly she wasn't paying attention. (She says otherwise.) But whatever the case she was shocked when the car suddenly slammed on the brakes all by itself and STOPPED at a red light before she could hit the car in front of her. Got into the anti-locks and everything.


I don't know how important the adaptive cruise control thing is, but the anti-collision technology is the real deal. And of course if you have THAT there is no real excuse not to have adaptive cruise control. It's just software at that point. They only put it in the high-end trim levels because it's an excuse to charge more money.

-mickey

Adaptive cruz is my desire along with collision control.

Collision control speaks for itself. Adaptive cruz would make my Tulsa freeway driving WONDERFUL

Been looking at the 2018 TSi 1.8L Golf base.

While I'm set for the *fix*, I can switch to BB if the Base has this.

Or I can even slug (approx) 2K more at the acquisition.

My BB is $25,626 and I have until Sept (?) 2018 to do the BB

With that in mind I'm sure I can even do the SE mid grade Golf and drive 3 years FREE and put a little cash off the table in the process.

Thank you VW
 
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