This is probably too old now, but for future members who encounter this same problem.
This happened on my 96 SSEi, one or both of the two pulleys at the front (one grooved and one backside) went. I think the grooved pulley was the SC belt tensioner, and it is a LEFT HAND THREAD!!
Found that out the hard way. It needs to be left hand thread as you need to cycle the tensioner by the torx bolt in order to install the belt. I broke it, tapped it out to the next size and put some loctite to hold it. Worked good enough to get it all back together, but had to remove the whole bracket with the coils.
The next one to go is the "pulley on a stick"...the larger, back side idler lower down. No fun on the 99 and older cars as the motor mount needs to come off. Enjoy!