All Saturn models utilize a timing chain driven, interference-type, non-freewheeling engine. If the timing chain breaks, the valves in the cylinder head may strike the pistons, causing potentially serious (also time-consuming and expensive) engine damage. refer to Engine & Engine Overhaul for information on servicing the timing chain.
Despite the potential for serious engine damage, the manufacturer does not give a recommendation for timing chain replacement as a preventive measure. Such replacement, however, may be prudent on high mileage engines.