Replacing the timing belt on an '01 VW Jetta should be accomplished every 60,000 miles. This is determined by examining the previous service history for the engine. VW does not express mileage at which the belt should be replaced. This engine has been identified as an "interference engine" (one with little clearance between the valves and pistons if the cam stops turning) in which severe damage would occur if the belt should break or come off during operation.
Raise and support the vehicle on jack stands. Remove the passenger side wheel, using the 1/2-inch drive breaker bar and appropriate socket. Remove the inner splash shield, using the appropriate size 1/4-inch drive socket.
Turn the crankshaft clockwise to align the timing marks--one on the crankshaft pulley with the arrow at the 12 o'clock position, and the other in the hole on top of the transmission bell housing, which has a mark on the flexplate the aligns with the arrow on the housing.
Remove the accessory drive belts by loosening the tensioners with the appropriate socket and removing the belts. Remove the crankshaft pulley bolts, followed by the large center bolt, using a 1/2-inch drive socket. Remove the water pump pulley, using a wrench, and remove the timing belt covers.
Check the timing marks on the bell housing and at the camshaft. The camshaft marks should be vertical, aligned with the arrow on the valve cover. Loosen the tensioner nut, using a wrench, and remove the timing belt.
Install the new timing belt on the right side starting with the crankshaft sprocket and intermediate shaft sprockets. Disregard the marks on the intermediate sprocket. Take the belt up and over the camshaft sprocket and down behind the belt tensioner.
Install the lower timing belt cover, water pump pulley and crankshaft pulley. Remove the distributor cap, using the appropriate 1/4-inch drive socket. Check the crankshaft pulley alignment, the camshaft alignment, and the alignment in the hole on the transmission bell housing.
Move the intermediate shaft until the distributor rotor is facing the alignment mark on the distributor housing with the rotor. Install the belt tensioner tool and loosen the belt tensioner once more. Pull the handle clockwise until the belt has sufficient tension so that the belt can be twisted just 90 degrees. Tighten the tensioner bolt.
Rotate the engine clockwise twice. Recheck the timing marks. Replace the rest of the parts in reverse order of removal.
