Last week I was driving home in 2002 WS6 with 113k miles and heard what I thought to be an exhaust leak out of nowhere. I revved the engine and it got louder but at idle seemed to disappear. I have a cutout so that may have covered it up. I just got two new cats so I thought maybe the bolts were loose.
I parked it and let it sit and the next day I get underneath to check the cats and everything seemed fine. So I try to start it and hear this really loud grinding noise and the engine doesn't even try to turn over. I do some searching online and read it could be the starter, bad ground, or battery not putting out enough amps.
I get a brand new (not reman) starter today and hear the same noise. Check the ground and wires and everything seems ok. I take the <2 year old battery to Autozone and they say it's fine. I then check the inspection cover and look at the flexplate and notice a small crack.