when i give it gas i get a knocking noise my exhaust manifole is cracked but the car drives fine but a bad knockin knoise when i give it a load but when im coasting cruizin its ok no noise what u guys think connecting rod? time for new motor?
need answer asap

 

a new exhaust manifold pehaps????

 

nosise still there could it be a valve adjustment or timing?

 

and only arounnd 2 - 3 rpms