I bought a 1994 CSE in May. It's the 2.6 Liter engine, normally aspirated, and has the R-134 based air conditoning system.
My mechanic (an independent Saab specialist) noticed that the serpentine belt was shredded and about to slip off. He recommended replacing the tensioner because in his experience that was that was normally the cause. In the process, he discovered that the tensioner had been replaced once already and that the A/C compressor was bad. He replaced the tensioner and belt, plus he gave me a compressor that he had lying around the shop. Because it was too cool to charge the A/C properly, he left it unplugged and I also programmed the control unit to always come on in ECON mode so as not to try to engage the A/C.
On his recommendation, I watched the belt for a week or two, and didn't notice any problems.
I finally couldn't "take the heat" and went back to complete the A/C charge. My mech immediately noticed that the belt was once again about to come off. He is pretty much mystified, and can only offer that a new compressor "might", stress "might" solve the problem. Besides the $750 for a new compressor, it turns out that there are none available in the U.S. for another few weeks.
Anyone have experience with this problem?