Timing System
WARNING: This page is about a different car, the 2010 Chevrolet Aveo. However, it is still accessible from the selected car via links, so may be relevant.
Courtesy of GENERAL MOTORS CORP.
The crankshaft is connected to the intake and exhaust cam shafts by using a timing belt (1). An automatic tensioner (2) and idler puller (4) maintain proper belt tension and increase the wrap angles around the drive gears.