Audi A6 2.5TDi 103KW

Hi there...

This is my first message on this great board. Congrats for all the wonderful work you're doing. I live in Europe, Germany.

And here is my first question as well...
I have this car(Audi A6 2.5TDi 103KW - 140HP) made on 01.1995, so it is not listed as safe for using biodiesel. Ignoring this I filled my tank several times with BD, and had no problem so far, but I would like to know more on why it isn't safe to use BD, what could happen if I continue using it and what can I do to make my car BD friendly.

In the list of BD friendly cars I can find Audi A6 made starting 09.1995 but not the ones made earlier. Anyone that knows what was changed starting that month?

Hey... thanks a lot and see ya arround

i think that you can have (or not) some problems with the tubing.. rubeer tend to dry and break.

Biodiesel affect rubber a bit (what ive read) but if all your hose or pipe are made from other material that should be fine!

im not a pro on the BD but if your car hasent have any problem you should continue... it's better for the environement and for your car (cleaner hose and pipe and less deposit and also higher cetane! and you dont rely on petroleum

Some of the fuel lines may not be made of biodiesel compatible materials. The degradation process isn't incredibly quick, so you could either just keep using biodiesel without changing anything, and watch for signs of degradation, or go ahead and change the lines now.

If you decide to change the lines, you could go with either viton tubing or the Therban tubing that VW uses.

If you decide to change the lines, you could go with either viton tubing or the Therban tubing that VW uses.

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hi mike... thanks for the answer...
do you know by any change what lines could be with problems?
lines starting from the filter? or the lines that return the fuel that is not used by the engine? any idea on the price?

thanks

Welcome to TDIClub.

The fuel lines to be exchanged are most likely the ones under the bonnet, however unfortunately this is not guaranteed

On VW cars, the fuel lines going to/from tank have been made from more durable (and BD-compatible) materials for quite some time.

Keep in mind that there might be also a few seals to be replaced in the fuel system.

I have a question for you: how is your V6 TDI engine running? Any problems to date? At what mileage?

I am looking into buying upcoming re-styled Skoda Superb
(Estate, 4Motion, 2.5V6TDI, in 2004 or 2005 ), and I am curious how this engine behaves long-term. I have heard that there used to be a few problems with their fuel pumps

Welcome to TDIClub.

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thanks

The fuel lines to be exchanged are most likely the ones under the bonnet, however unfortunately this is not guaranteed

On VW cars, the fuel lines going to/from tank have been made from more durable (and BD-compatible) materials for quite some time.

Keep in mind that there might be also a few seals to be replaced in the fuel system.

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I have to wait for some more feedback.
It has to be that someone from Europe has a car like this running on BD.

I have a question for you: how is your V6 TDI engine running? Any problems to date? At what mileage?

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My engine is the old type, 5 cylinders in line, not 6 in V.
I bought the car in 2001 when it had 6 years and 140K KM.
Almost two years later and 65K KM after I can say I am happy with it, not a single problem with the engine(some more than normal smoke, but I'll get a Vag-Com, and check what the problem really is), it doesn't eat ANY oil(I serve her only quality 0-40 oil) and it eats between 6.7 and 8.2 l/100KM, average 7.3, and 8.2 after some 700KM only city driving.

I am looking into buying upcoming re-styled Skoda Superb
(Estate, 4Motion, 2.5V6TDI, in 2004 or 2005 ), and I am curious how this engine behaves long-term. I have heard that there used to be a few problems with their fuel pumps

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I really can't tell you something for sure, only what I heard: It's a very good engine, plenty of power and it has in average some 8l/100KM. As about Skoda, that's a good car but if you want to resell it several years later go get a VW or even better an Audi, otherwise you will lose quite some money.

I really can't tell you something for sure, only what I heard: It's a very good engine, plenty of power and it has in average some 8l/100KM. As about Skoda, that's a good car but if you want to resell it several years later go get a VW or even better an Audi, otherwise you will lose quite some money.

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Well, look at my name and guess what car I am driving

My current Octavia is great, and as for Superb, I'd expect the same.
Resale value is not much bother to me, since I tend to run cars till the end of their usable mileage (150k miles +), half of it across Germany at 110mph+ (overnight).
But what is important for me in a Superb, is the extra 10cm+ (My rough guess is actually extra 15cm thanks to different seats) of legroom over Passat. It is even more than in Audi A6, and I happen to have a Severe Acute Legroom Problem (100cm inseam, and 197cm overall height )

Oil consumption wise, my Octavia TDI takes no oil whatsoever in regular daily commuting, but starts taking it when I go over 100mph for long periods of time. Usually I have to add something like 0.5-0.7l of oil per 1000km at 170km/h.

If you decide to change the lines, you could go with either viton tubing or the Therban tubing that VW uses.

Click to expand...

hi mike... thanks for the answer...
do you know by any change what lines could be with problems?
lines starting from the filter? or the lines that return the fuel that is not used by the engine? any idea on the price?

Click to expand...

As Octavian said, I'd suspect primarily the ones under the hood (er.... "bonnet" ). So, from where the lines enter the firewall into the engine bay, into the fuel filter, then to the injection pump, to the injectors, back to the filter, and back to the firewall. Can you see the fuel lines underneath the body of the car, back near the fuel tank (you can on our TDIs, so I'm guessing you can on yours)? What do they look like? (i.e. black rubber, or a harder blue material?)

Many people in the US with diesel vehicles that were produced before the changeover to synthetic rubbers have run them on biodiesel. The owner of the store where I get my biodiesel has a mid-80's Mercedes wagon that he runs on biodiesel. He went a few years running it on biodiesel before the lines finally gave out.

I recommend going with viton tubing. If I remember correctly, most of the lines should be 5/16" Inner Diameter, except for the lines after the fuel filter (so everything except the lines between the filter and the injection pump, and from the injection pump to the injectors). Do a search on here for "injector fuel lines" or something like that, and you should be able to find the size of those.

I'm not sure if they deliver to Europe, but you can get viton tubing reasonably priced frlom McMaster-Carr at:
http://www.mcmaster.com/asp/loadpagerange.asp?pagerange=*97,690&descid=37863&term=Viton+Tubing
(edit - hm, that link didn't work too well. Try just going to www.mcmaster.com and searching for "viton tubing") For the lines going from the firewall to the filter, you'd want the stuff that's 5/16" ID, and either 9/16" OD or 1/2" OD (the stuff with 7/16" OD is too thin-walled IMO. When bending it, it would be more likely to pinch shut).