The recommended replacement for the timing belt on the 1990 through 1993 Geo Storm 1.6 engine is 60,000 miles. This recommendation is a result of a study of the service history for this engine. The 1.6 engine has been identified as an interference engine. This means that the engine was built with no clearance for the valves to clear the pistons in the event of a failure of the belt and subsequent damage is likely to occur. Never turn the crankshaft with the belt removed for danger of the valves hitting the pistons.
Support the engine with the floor jack. Remove the right engine mount bracket. Remove the wiring harness from the upper timing belt cover. Remove the accessory belts and the upper timing belt cover. Lower the engine to gain access to the crankshaft pulley.
Raise and support the vehicle on jack stands. Remove the right splashguard. Turn the crankshaft clockwise and line up the timing marks for top dead center on number one cylinder. There is a groove on the crankshaft pulley that should line up with the O timing mark on the timing belt cover. Each camshaft sprocket has a groove on one of the teeth. The left sprocket has an I on it and the right one has an E; both of these letters belong straight up and the grooves face each other.
Remove the crankshaft pulley bolt and the pulley. Remove the accessory belt idler pulley and the lower timing belt cover. Lower the vehicle. Remove the exhaust manifold heat shield. Remove the power steering pump and move it forward. Remove the accessory belt tensioner pulley.
Remove the right motor mount bridge and the lower timing belt cover. Loosen the tensioner pulley bolt and move it away from the belt and loosely tighten the bolt to hold the tensioner out of the way. Remove the timing belt.
Check the tensioner pulley for smooth operation--replace it if necessary. Temporarily install the lower timing belt cover and check the timing marks prior to installing the new belt. Remove the lower cover.
Install the timing belt making sure to keep all the tension on the right side away from the tensioner. Start by installing the belt from the crank pulley over the water pump inside of the idler and over the right camshaft sprocket, then the left sprocket and down on the inside of the tensioner.
Loosen the tensioner and push it firmly to apply tension on the belt and tighten the bolt to 31 foot pounds of torque. Install the lower timing belt cover and crankshaft pulley. Check the timing marks one last time. If they are lined up turn the engine clockwise two turns and recheck the timing marks.
Install the components in the reverse order of removal and torque the crankshaft bolt to 108 foot pounds of torque.
