Re: biodiesel users...whacha got? (SpoolinFSI)
| Quote, originally posted by SpoolinFSI » |
| Do the cars have to be modified to run pump biodiesel? |
Depends on the biodiesel concentration and engine. My unmodified 1984 Rabbit 1.6L D runs on 20% Biodiesel.
Biodiesel is a great solvent so it lifts crud and rust from the internal fuel tank lining of old cars like mine, and that crap will flow to the fuel filter, eventually clogging it. Fortunately the VW diesel fuel filter is located in the engine bay (not under the car) and is very easy to access/replace. Not expensive either. The Rabbit has been running on Biodiesel for a month now with no clogging yet.
I have a spare fuel filter in my trunk just in case my old one starts to clog. After several months of Bio use the fuel filter change interval should go back to normal.
I also used 20% Biodiesel in my 1997 Golf 1.6/1.9TD with unmodified fuel lines for 6,200 miles and no clogging. A '97 fuel tank is newer & cleaner so I don't expect clogging.
Running 50% or higher concentration of Bio may be a concern for early diesels including MKIII TDIs and some MKIV TDIs. Bio eats through rubber over time, so fuel lines need to be replaced with Viton or Urethane; these are the popular materials. Viton is expensive, Urethane can be ordered from a motorcycle shop for about $1USD/ft and is available in cool transparent colours.
Unfortunately, on older VW pre-TDI diesels, prolonged use of high Biodiesel concentration can dissolve a couple big seals inside the injection pump, which can be costly to replace. Thus, I will stick with 20% Biodiesel for my 1984 Rabbit (currently 400,000km). Besides, 20% seems to be the best mixture for power and fuel economy.
My 1997 Golf 1.6/1.9 has a performance fuel pump that will be re-updated with viton seals just in case I want to run B100.
I don't know how well the seals inside TDI pumps can hold up to BioD.
Modified by Malone at 4:31 PM 4-24-2006
