While the 1982 Mercedes-Benz 300TD has performed flawlessly through Alabama, Mississippi, Louisiana, Texas, and New Mexico, the filtration system, uh, hasn't. Thankfully I took the advice of Dan, the mechanic who guided me through the vegetable oil conversion, and brought some extra filters along for the ride.
Leaving Atlanta with a couple of gallons of biodiesel still in the tank, my friend Hugh and I decided to fill it to the top with canola oil from Target. We didn't want to dilute our waste vegetable oil with anything, so we thought it would be fun to throw in some garden-variety cooking oil that you might find in your mom's pantry and blend it with the refuel biodiesel
already in the tank. Sure enough, the Benz performed flawlessly, the only performance changes being a smoother idle and a cool smell wafting from the tailpipe.
But things got ugly probably about seven or eight gallons into our first tank of waste vegetable oil the next day. Waste vegetable oil is not
see-through like canola oil; it is dark caramel brown, and our first batch was even a touch opaque. But having filtered it painstakingly through 25-micron filters, I was confident that there were no particles present that would cause trouble.
There were particles. And the orange 4-micron Baldwin filter--and Mercedes primary and secondary filters--did their job, filtering out those small particles and protecting the injection pump and engine from contamination. But that Baldwin could only take so much, and on a lonely two-lane road somewhere outside of Selma, Ala., the engine began chugging and ultimately shuddered to a halt, starved of fuel that would no longer pass through the clogged Baldwin.
Panic set in, wrenches came out, and I routed the fuel around the Baldwin 4-micron, figuring it was clogged. Correct. We were back on the road, and finished out the day without incident. But the primary and secondary filters were doing double-duty at that point, and I was to find out the next day that they, too, would soon grind our progress to a halt when they became filled with tiny bits of detritus from thousands of breakfasts and midnight snacks from the Majestic Diner
in Atlanta.--Colin Mathews
---Make sure you check out our partner sites dedicated to focused news, reviews and more for Ford, Chevrolet, Toyota, Honda, and the Toyota Prius.