1994 Other Oldsmobile Models Noise around harmonic balancer

My daughter's 1994 Olds 88 LSS has a 3800 in it. It has a rattling, not a knocking, right around the harmonic balancer pulley. It is louder at idle than it is when the gas is given and RPM's increase. The rattling is pretty loud. I lowered the oil pan and rotated the crank and everything looked fine. The timing chain had some play in it, but I don't know how much play that it really should have. I don't know if anything but the chain could be rattling like this. I was going to take the timing chain cover off, but I cannot remove the harmonic balanced bolt in the crank. A cheater bar and a 3 foot pipe would not budge it. Any hints on what the rattling is on a best guess and how to bust the bolt loose? Thanks!

Jesse