2006 hyundai Azera.. cold engine has a light clicking noise

When the engine is first started I can hear a slight ticking or tapping noise that disappears after a few miles of driving. The vehicle is nearing the end of the factory warranty mileage of 60K. So I want to have them repair any problems, now. I left it overnight with the dealer for analysis, but they claimed they could not hear anything. I believe that it may be a lifter or a tappet but am not sure. Does it sound serious or is it not important? Should I bug them or not?


J. Ries