UPDATE: for you greasers, polymerization
 

Read through this thread from the TDI club i think it should solve the glow plug heater polymerization problem.

http://forums.tdiclub.com/showthread.php?t=151177

Well, I'm not sure about glow plug heaters, but I am glad to read that BioD cuts polymerized WVO - I'm running 2 micron filtered WVO in my GreaseCar setup and B20 in the main tank - on both the Benz and VW. Hopefully that will help cut down on internal polymerization.

I do know one thing for sure, though - the motor in the Benz definitely prefers WVO to B20. On WVO, it runs really nice and smooth with little/no smoke, great power and accelleration, and idles really smooth.

This smoothness can be had on straight diesel on the 603 too (and definitely b20). I've been there with the bosio nozzles and quality diesel fuel. Some of the clicks and clacks are back now, but that's due to other SNAFUs. That said, with time, frustration and a few more gray hairs the 603 can be silenced.

Even Biodiesel Can Polymerize
 

That's what the "Iodine Value" in the ASTM index indicates: The lower the iodine value of the feedstock, the less likelihood of polymerization. The Europeans pay far more attention to this factor than the U.S.

Peace,