Toyota Repair: tapping, spark plug wires, toyota corolla

Question
1996 toyota corolla 1.6L,with air conditioning,.There is a constant tapping noise from engine?..Is there a common problem of what sounds like lifters tapping on this year and engine ,although I can't seem to isolate a particular cylinder by means of removal of spark plug wires.

Answer
There is no common problem concerning a tapping noise, the valves normally don't go out of adjustment, can't be of much help without hearing the actual noise, you may want to just check the valve clearance just be sure that's not the problem, noises can also be caused by worn pistons or bearings or possibly a  broken valve spring.