Friday, November 12, 2010

The Jetta TDI Grease Machine


I finally did it. I decided to just go out and buy a nice car to run on veg. I figured, hey, why not? While older vehicles are more tolerant, newer vechicles give you more of a reason to do EVERYTHING RIGHT.


For me, doing everything right from the get go was a step by step process in itself. I had searched for months for a Volkswagen TDI between the years of 1999.5-2003. I decided on a 2003 Jetta that I found at a dealership in Southern California. The exterior was black, my favorite. The interior had cloth seats, the transmission was automatic, and it had just under 100,000 miles. I looked it over carefully and was driving it to my new home the next day.


But the work had just begun. Before I could even think about converting this car to grease, I had to make sure everything was working perfectly. I had the timing belt changed, the engine oil changed and got an oil analysis (great results), the compression tested (was in the normal range or about 450 psi per cylinder), the trasmission fluid/filter changed, the coolant changed, the water pump changed, the diesel fuel filter changed, and the fuel system cleaned. The glow plugs, air filter, Mass air flow sensor, vacuum lines, and electrical connections were all in good shape. The exhaust gas recirculation (EGR) valve and air intake were cleaned out as they are known to fill up with carbon. After all of this I had a car that did not smoke at all. A car that started right up and idled smoothly. A car that didn't burn engine oil or have blow by. I was ready to install my Greasecar Kit!


It took me about 25 hours over the course of a week to install the vegetable fuel system. My grease system consists of an 11.5 gallon aluminum tank in the trunk that is heated with the engine coolant through a copper coil, an aluminum fuel line sitting inside the coolant line all the way up to the engine bay, a heated filter assembly for the grease, a flat plate heat exchanger for higher veg oil temperatures, and two switching valves. Inside the car is an exhaust gas temperature gauge to monitor combustion quality and a boost gauge to monitor the turbo.


As far as the kind of oil I'm dumping into this car, I don't want to take any chances. I'm currently buying oil that's been dewatered and filtered down to 1 micron. I have met with the people I'm buying the oil off and their practices are acceptable to me. 1.50 a gallon is what I'm paying, and that still beats the price of diesel by a landslide.


Operating the greasecar system (especially on a nice car like the Jetta TDI) means a few important things:

1. Always wait until a few minutes after the engine temp. gauge reads 190 degrees before switching to vegetable oil.

2. Only use clean, dry oil and make sure it's being heated well prior to injection. (Hot engine, hot oil).

3. Always purge for approximately 30 seconds 3-5 minutes before you shut down. Running the engine hard before shutdown on diesel fuel ensures a good flush of all the veg oil from the injection system.

4. Do not sit in traffic for longer than just a few minutes. Combustion temps. can drop at this time and lead to incomplete combustion and carbon deposits in the engine.

5. Monitor start ups. If there is any smoke or it starts hard, there could be a problem and purges may need to be longer and/or diesel may need to be run a bit longer after the purge cycle.

6. Check the engine oil regularly and it never hurts to have an oil analysis done to see how the engine is wearing with WVO use. I plan on changing my engine oil every 4-5k.


....and now I get to drive a car that gets 40-50 miles per gallon, has plenty of turbo power, and is running a clean, renewable fuel. I'm so stoked it's ridiculous.