After listening for a few moments he shook his head. Stan nodded glumly. Kill the ignition and we'll have a look. It took less than five minutes for Gus and Stan to remove the two valve covers. Gus wiped the oil film off the left cylinder-bank valve gear, and examined the exposed rocker arms.
Engineers call it 'valve-spring to rocker arm interference'.
He disconnected the center high voltage cable to the distributor to prevent the engine from starting, and then directed Stan to turn the starter switch. The three working together make the clicking sound. The effect is most noticeable during idle. The only cures are to either replace the three arms, or to grind away the interfering surfaces on the original units. Either way, it's a warranty job on a car this new.