i recently bought a 94 blazer 4.3L from my brother and it has many leaks. the one that is troubling me most is a leak that appears to be coming from behind the drive shaft pulley. it only recently started and i first thought it was from my water pump but have determined its not. my question is what would cause this leak and how to i fix it?

 

Leaking what - coolant or oil?

 

not sure, it is a very oily substance with a tinge of green to it. it doesnt smell like coolant nor does it have the sweet taste. im very puzzled by this.