ls missfire and motor noise??????????

[lincolnlsman]

hi guys im new to ford/Lincoln cars and i bought this ls and b4 i bought it the vcgs had been replaced and all brand new coils but every now and then it will start burpin a lil miss on time sounds like just one cyl no check eng light???????? and this car makes like a knocking noise/ valve tapping when in any gear in which the motor is under load till you hit about 1500ed rpms or put it in park/ neutral any help please