intermitten engine tap

[rich30769]

Hello everyone. Recently I just did the head over on my 86 300E. Car ran fine and all, then recently I've noticed the car has a tapping sound that comes and goes(mostly stays though). It does this at all operating temps. One minute car's quiet then all of a sudden I can hear a tapping sound coming from the front of the engine. Haven't been able to pinpoint exactly where it's coming from, then just as quickly as the sound started, it goes away(now it just stays). Is there anything that has to be readjusted when you do the head over on your car? Does the rocker arms have to be readjusted?

Thanks

P.S.: Here are other symptoms. When I'm at idle it seems as if I'm running a modified cam(like it has a miss), but when I get on it or just give it enough gas to go, it runs fine and smooth. Can a rocker have not been tighten to spec and have backed off alittle? Otherwise like I stated early the tapping noise which is coming from under the valve cover and the rough idle, does this sound like during refitting I failed to tighten a rocker arm properly, also when I give it gas the tapping increases with the motor . Love my car but it's starting to piss me off.

Once again,Thanks