[roadrunner2]

You have a timing chain NOT a belt and yes, it is a non-interference engine.

Gates belts info.

It's unusual for a timing chain to wear out at only 80k miles. It IS possible to have a plastic gear lose a tooth, but that would throw the timing off and the engine would run rough and (apart from the noise) it's running fine, right?

Do what Airjer suggested and remove the belt and test.

Before you reroute the serpentine belt back on, check by hand (Engine off and key removed) each pulley by turning and applying side pressure at the same time.

Pay particular attention to the serpentine's tension pulley.

BTW, most timing belts also have a tension pulley.