i've heard this word before and realy it scares the crap out of me and i really don't kwow why.

I read a long article today about polymerized oil in the crank case alot of people were relating to wvo and diesel mixes because some of the wvo was running past the rings into the crankcase.

But this is not what i'm talking about now

i'm talking about polymerized fuel (specificly biodiesel).

1) what is it
2)what causes it
3) how do you tell if you have it
4)what damage can it do

Thanks guys this is a great site and I know some one here can explain

HIggins