My ‘06 has a rattle at about 1000 RPMs. I’ve only noticed this after swapping out a cracked number 6 piston (Didn’t pull motor). I checked my balance rates and all seems good, original injectors 173k miles. But during my search I noticed that a bolt on the bottom passenger side of the bell housing was backing it’s way out. I tightened it but still have the rattle. I’ve only noticed the noise while the truck is warm and I have no lights or codes. Help