I think you may be on to something. I know they haven't been changed since I bought it new (128,000 miles on the ODO), so it may be time. I took the vehicle and had the codes read. There were misfires on multiple cylinders. Any suggestions on a source or particular brand? Should I stick with the original leads?
The telltale tapping of lifters or tappets is pretty distinct. This sound is hard to describe, so I understand it would be pretty hard for you to diagnose over the Internet. But its more of a irregular, sporadic metal-on-metal rattling sound that eventually goes away after the car's well warmed up. I was wondering if it could be related. I'll stick with the leads angle for now, though, and see if it goes away after I change them.
One more question if I can: I see no listings or mentioning online for distributor cap and rotor for the 2.5 V6 anywhere. Am I right in assuming the 2.5 is not so fitted?
Thanks so much again for your assistance. It is greatly appreciated.