After every oil change I've been sending it to Blackstone Labs to have it analysed. They have been finding high levels of potassium, sodium, and lead in the oil. We both thought that the veggie oil was contaminating the motor oil and causing excessive wear on the engine. So as an experiment I drove the car about 2,000 miles on straight diesel fuel and had the oil tested again. The potassium and sodium were still present, thus it is probably a coolant leak somewhere.

I put all of the oil reports online, the comments tell a bit more of the story.

-Jay