Oldsmobile/Buick Repair: 1987 Delta 88 Engine Rattle, pulley bolt, serpintine belt

Question
Recently I had repaired the exhaust on my '87 Delta 88 (boy it was loud) and after I did, I noticed there was a loud rattle coming from the engine. At first is sounded like it was coming from the alternator like the bearings were shot, but after I removed the serpintine belt from the engine out of curiosity and cranked the engine for a few, the rattle was apparently coming form the main crank pully. The pulley does not seem loose at all, as in any shaking or rocking back and forth but it seems to have play in it, meaning the pulley does about a full half turn or so, then makes a light clang sound as if hitting the metal. This is leading me to believe that something is loose, but the pulley bolt is very tight. I believe this is a pulley/balancer combined unit.  Do you think this to be an internal engine problem, or would a simple replacement of the balancer/pulley assembly be sufficient to fix and wuiet this down? Thanks in advance.

The engine is a 3.8L V6 MFI

Answer
hi john, yes this is a notorious prob for the 3.8.john i don,t know how tell you this except flat out lol.this pulley is shot you need to get it changed.although not cheap a lot cheaper then a new eng .figure a cpl hundred or so unless you put it on ,easy enough to do but will require a very powerful impact wrench,as this bolt has 200 ft lbs of torque.good luck please vote for me billymac