the guy i bought my cobalt from had an extra block laying around and some cylinder-heads and other engine stuff and he told me that he had to replace his motor because the balance shafts came out of alignment or something weird like that and it destroyed his old block? i have never heard of that happening with our cars but he did say he could show me some pics of the damage as proof. but he also told me that when the balance shafts went bad, it caused damage to the head....my brother is a mechanic and he told me that there is no way the head was damaged by balance shafts going out....what do you guys think? im just curious.

 

If the balance shafts went bad and somehow that chain got tangled with the timing chain I could see it damaging the head that way but can't think of any way how it would damage the head otherwise.

 

balance shaft could of broke and seized up, breaking the timing chain and letting all hell go loose