If you have had the car for the entire 133k and have never changed the belt, now would be a good time. Usually due between 85k-100k depending on make and model. Should say in your owners manual.
Don't fail to replace the belt soon as you are on borrowed time. If it breaks your engine may be ruined.
Saab's four cylinder engine has a timing CHAIN not a Belt and they should last for the life of your vehicle. If you are hearing noises could be the tension pulley bearing. See Saab Central Forum on this matter. Volvos had a Belt and yes if not changed at around 100000 klick area and it broke one was in deep dodo.
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