well clean ur plugs and see wot happens.
also check your oil dip stick to see if it is using any oil (most likely it will be down).

has this happened all of a sudden or slowly building up

well spark plugs are black as hell..and the motor was running fine prior..its so close from starting and it kicks but just not enough???

check your spark plugs as these are tell tale signs as to whether or not oil is getting into your combustion chambers.
also blue smoke will poor from your exhaust at the 1st sign of oil in the cylinders.

if it was a blown head gasket it would run hot all the time and lose water aswell. its more likely that your rings are worn out and need replacing.

as to why it wont start, it could be any number of things.
some more details on how it doesnt start would be useful.

i think oil is getting in the cylinders of my L20B..i have overheated once before..could that have ruened my head gasket?what else could cause the oil in the cylinders..
i found this problem by starting my engine and the engine wants to start but does'nt??whats going on?