Does the coolant in the little resivior right behind the bumber go back into the engine, or is that just for over flow? I opened up that resivior's cap today and it has all **** floating in it. Looked like rubber from the little hose in there or from the seal on the cap.

 

it goes in and out of the engine.

 

As the coolant heats up it expands and pressurises the cooling system. When the system reaches 13psi the radiator cap bleeds some coolant out of the radiator and into the overflow bottle so the pressure doesn't get any higher. When the engine cools the coolant contracts and gets sucked out of the bottle and back into the engine.

 

****! So that crap in there is probably ******* up my engine, right?

 

^

 

Anyone? This is really freaking me out?

 

No dude, chill out, it's not ******* up your engine.
By the same token it is not good for it by any stretch of the imagination, so you should probably do a full coolant flush sometime in the near future, however don't loose any sleep over it