slight muffled knocking coming from engine
 

so awhile ago i have done the 120k service of replacing the spark plugs, spark plug wires, distributor caps and rotors. And replaced the timing belt. and throughout I've gotten a misfire for cylinder 7 and it comes back sometimes. Just recently I've been hearing a slight muffled knocking coming from the engine around where cylinder 7 is. I do not believe it's a rod knock because it's not an aggressive knocking it sounds as if you were tapping on a mouse pad on a desk. it is hear a bit louder when in drive rather than park. Any help and advice on what could be wrong would be greatly appreciated.

You'll need to post a video.