The camshaft is driven from the crankshaft by a toothed belt, which also drives the coolant pump. On the 1.9 liter engine, the camshaft controls the valves through the tappets. Thermal clearances in the valves are regulated by replacing the gaskets between the pushers and camshaft cams. On the 2.0 liter engine, the camshaft operates the valves through rocker arms that abut against hydraulic stops. These stops automatically maintain the required thermal gaps.