my daughter recently bought a 2004 spyder 3L v6. when she took me for a ride, i heard an ominous thumping noise from the floor which sounds like a loose rod. just one loose rod. barely audible when cold, louder after warmup. funny thing is i can't hear it from outside the car with the hood up. could it be (i pray) something else? if it is a rod, does that engine use removeable bronze bearings? also, can it be repaired from underneath thru the oil pan? lastly does the v6 have a timing belt or chain? on the plus side, the car is gorgeous and drives like new. any info is appreciated, as i am loosing sleep over this.