Kind of a grind/rattle when I shut off the car. Sounds like its coming from the passenger side. Possibly under the car.

Its not the torque converter. I tightened it up and put loctite on the bolts. The bolts had backed off a bit in the past but they are snug now and the noise remains.

 

Exhaust rattle maybe? The starter solenoid shouldn't be engaged when the key is not in the "start" position and therefore not even touching the flywheel. I suppose it's possible though.

 

Doubt it man, unless your starter gear is stuck on your flywheel... in that case your starter should be toast fast.