A locked up 3800 will almost always be a broken rod or spun rod bearing. If it happens suddenly it is probably a broken rod. If it ticks, then knocks, then looses oil pressure then locks up over a period of like 30 minutes its probably a rod bearing. As said above the only reason to unbolt the convertor is to pull the motor. The convertor would have to have lockup stuck on AND have a something broken inside the trans locking it internally, all of that happening at once with no warning would be nothing short of magic. It doesnt matter if the car was driven by your great grandma and had the oil changed every 2500, it can still spit a rod out of the block on a whim if it so decides. Heres a pic from a job I did in feb. 2001 Intrigue driven by a middle aged women. BTW the pan had to come off in the car to get the convertor bolts off, not a big deal
