Engine Problems.

Hi guys. Got a little problem I hope, my car has just started what sounds like tapping loud when accelerating and maybe misfiring, doesn't sound like it's knocking, the car starts up fine and idles normal-ish, just a little louder until you give it a rev and it sounds like a tractor, firsts thoughts are coil packs but there is no engine management light on which I thought there might be and it does still seem to pull just sounds like death. Has anybody had the same issue or could shed some light on this for me but I know with out hearing it it will be hard to do.