It was actually just the opposite. No engine noise when at idle. He would shut off the cylinder and it would rattle. Turn it back on and the noise would stop. I did ask about wrist pins that day and he did agree that yes when an engine would come in knocking as they turned off the cylinder it would go away. He thought the engine just ran to smooth to be internal. He felt that as they turned off the cylinder the missing was shaking the crank and the possibly cracked flex plate.

I have been trying to figure out this rattle for like 4 years. I have asked here, other dealers and shops, everyone said it was exhaust rattling, nothing or normal sounds.. I drive trucks every day and just never believed this was normal "sounds". Never wanted to just start taking everything apart without knowing for sure what was wrong.