I just got done with a engine rebuild on my 96 3.8 and had a sound like a ideler pully was bad so I replace both of them. Still had the noise but it comes and goes? Finaly took a hose and used it hear the source of the noise. Found it! It was the cam sensor assembly. Looks like just the bottom of a distributer. It had dried up and had no lube so if you have a wierd noise from your 96-97, these were known to cause this.