Do I need to do anything to my 1997 VW Jetta TDI to use bio-diesel fuel?

Question

have finally found a station that pumps biodiesel fuel for the public in my area of Maine. We are going to buy a 1997 Jetta TDI that already runs on diesel and would really like to convert it to biodiesel. We've asked many people and done a ton of research but cant seem to find a consitant or even reasonable answer. So maybe you can help.

How would we go about converting our car? Do we need to do anything at all? I've gotten so many answers from just changing a rubber gasket occasionally to installing a convertion kit. I even got one mechanic that said it would require a complete overhaul of the engine. Biodiesel is something I've been wanting to do with my vehicle for a long time and now that I have FINALLY found an affordable car in my area that has the possiblity of doing it at a reasonable cost, I'm looking for some actual facts on what it will take to do this.

Any advice or leads to a more informative sight, person, phone number, whatever would be lovely. Thanks in advance for any help that you can give.

Answer 1

If the biodiesel is produced by transesterification of fats it will be in the form of FAME (fatty acid methyl esters).  FAME makes an excellent diesle fuel, but it is also a solvent and may attack certain plastic components of your car's fuel system causing leaks and possibly fires.  You should check with the engine manufacturer to determine  the maximum percentage of FAME allowed in the fuel.  Many diesel engines are limited to 10% FAME.  Some, however, are designed to run 100% FAME, but may limit acceptable fat sources (many European engines designed for 100% bio-diesel are in fact limited to RME (rape methyl ester), made from rape seed oil).

Answer 2

I don't know the answer but one of the searches you could do is type in alcohl engines or something of that nature. Because i know that ethanol has a lot of alcohl it burns much hotter and much quicker. I will ask a friend who has spent a lot of time studying fuels.

Answer 3

biodiesel is just a mixture of methyl esters produced from (usually) vegetable oil. It is produced by two stage process, methoxylation (reaction of wood alcohol with sodium hydroxide) and esterification (reaction of the methoxylation products with vegetable oil. It will power any diesel engine and conversion is NOT necessary. The regular diesel fuel gels (becomes semisolid) at cold temperatures and requires addition og kerosine during winter months to prevent that.  Addition of kerosine works but robs the engine of some of its power. Biodiesel has much lower pour point (less tendency to gel) and thus not require kerosine addition.

The lubricity of both is similar (that menas your fuel injectors will not suffer from its use. The important difference is the regular diesel needs certain sulfur content as a lubricant.

Your car will not need any conversion whatsoever, it will run fine on biodiesel.

TDI engine means Turbo Direct Injection. The cylinder does not have what is called a prechamber and burns diesel fuel more easily than older diesel engines. Why would you need the overhaul of the engine??? Both regular diesel and biodiesel have the same cetane number (equivalent to octane number in gasolines). What you were told makes no sense.

Answer 4

Biodiesel and diesel are interchangeable, mixable and get the same MPG.

You don't need to do anything to the engine.

However if the car has "old style" natural rubber fuel lines, biodiesel can deteriorate those over time, but I don't think a car as new as yours would have that.

Also, biodiesel may loosen the old "gunk" in your fuel tank and lines, and that stuff can end up in the fuel filter.  So, after you've been running biodiesel, you might consider changing the fuel filter as a one-time thing.

Answer 5

anything...anything...ANYTHING rubber that will be in contact with the fuel needs to be replaced, you could go out and buy all of those but a kit usually has most everything you'd need

what exactly did this 'mechanic' tell you about why an overhaul was needed? the only thing that come to mind off the top of my head is a low compression ratio, cuz i belive bio-diesel needs higher compression then regular diesel to burn

Answer 6

I think it is great that you are taking the initiative to use Bio-Diesel fuel!  I do some research for a "green" start up and have come across a bit of information regarding Bio Diesel fuel.  In theory, a TDI engine requires NO modifications to use Bio Diesel fuel.  I actually saw a video about Bio Diesel on the web (couldn't find the URL, sorry!) that used a Jetta TDI to reiterate that TDI engines require NO modifications to use Bio Diesel.  However, there are some precautions that need to be taken as illustrated in the FAQ provided in the sources.  It says that fuel filters sometimes get clogged with residue when Bio Diesel is first used in an engine.  

Bio Diesel is usually a mixture of a petroleum diesel and Bio Diesel.  For example, "B5" means that the mixture is 5% Bio Diesel and 95% petroleum diesel.  This goes all the way up to B99.  I would recommend you start out at B5 just to ease your car into running on Bio Diesel.  Run it on B5 for a while and, get your fuel injection system checked out and if all is good, go ahead and start using the stronger stuff.

Answer 7

Nope!  Nothing. Nada. Just fill with Biodiesel and drive!!

No, you do not need to do anything to a 1997 Jetta to run biodiesel.  The 1.9 liter TDI engine loves biodiesel.  I have 4 diesels and absolutely no modifications are necessary for biodiesel.  

I did modify one car, but that was to heat the fuel to run straight vegetable oil.   For biodiesel just fill and go!

On one vehicle, the 190 diesel mercedes, I had to change the fuel filter after about 6,000 miles of biodiesel, because I noticed a slight loss of power when accelerating.

This is because regular petroleum diesel is very dirty!  It contains lots of soot.  At the pump, they usually give you a glove to use to keep your hand clean.  Biodiesel cleans the layers of accumulated soot from your tank and fuel lines over time, and the clumps of sooty particles can clog the fuel filter.

My suggestion is buy a fuel filter at the parts store, but DON'T change it yet!  No need to waste a fuel filter it if is unnecessary.  Keep it in your trunk, along with the wrench/pliers to change it.  If the filter clogs, you can change it at your first available opportunity.   You might not need to change it for a year or two.

Keep in mind you will notice when it starts to clog when  accelerating up a long hill, you won't have the power you usually do.  Changing the filter is not an emergency.  You won't harm the engine as a diesel is governed by restricting the fuel flow.  You can change the day you notice the power loss or wait 5,000 miles and do it then.  You will probably just notice it getting a little slower every day.

Because it is a 1997, you already have Viton fuel lines which can handle a certain percentage of alcohol with out degrading.  Pre 1994 vehicles require the rubber fuel lines to be changed.  You do not.

Just buy it, fill up on BioDiesel and drive happy, knowing you are preventing global warming, and reducing our dependence on foreign oil!