little leak by my head gasket

my 1998 pontiac bonneville makes a little grind noise only when i rev it up high so i took the engine cover off and show a little leak by my head gasket and i put my hand on the head gasket cover and every time i heard that noise i felt something hit/vibrate the cover part of the head gasket could that grinding noise come from having a blown head gasket the belt and pulley looks fine we put 134a refrigerant with oil in the a/c to recharge it becuase we thought the bearing didnt have enough oil