Should the camshaft drive belt/timing belt jump timing by a tooth or two, the engine could still run; but very poorly. To visually check for correct timing of the crankshaft, auxiliary shaft, and the camshaft follow this procedure:
There is an access plug provided in the cam drive belt cover so that the camshaft timing cam be checked without moving the drive belt cover.
- Remove the access plug.
- Turn the crankshaft until the timing marks on the crankshaft indicate TDC.
- Make sure that the timing mark on the camshaft drive sprocket is aligned with the pointer on the inner belt cover.
Never turn the crankshaft of any of the overhead cam engines in the opposite direction of normal rotation. Backward rotation of the crankshaft may cause the timing belt to slip and alter the timing.
REMOVAL & INSTALLATION
See Figures 1, 2 and 3
Fig. Fig. 1: Timing belt cover on the 2.3L and 2.5L engine
Fig. Fig. 2: Timing belt assembly on the 2.3L and 2.5L engine
Fig. Fig. 3: Releasing the timing belt tensioner using a special tool
- Rotate the engine so that No. 1 cylinder is at TDC on the compression stroke. Check that the timing marks are aligned on the camshaft and crankshaft pulleys. An access plug is provided in the cam belt cover so that the camshaft timing can be checked without removal of the cover or any other parts. Set the crankshaft to TDC by aligning the timing mark on the crank pulley with the TDC mark on the belt cover. Look through the access hole in the belt cover to make sure that the timing mark on the cam drive sprocket is lined up with the pointer on the inner belt cover.
Always turn the engine in the normal direction of rotation. Backward rotation may cause the timing belt to jump time, due to the arrangement of the belt tensioner.
- Drain cooling system. Remove the upper radiator hose as necessary. Remove the fan blade and water pump pulley bolts.
CAUTION When draining the coolant
, keep in mind that cats and dogs are attracted by ethylene glycol antifreeze, and are quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.
- Loosen the alternator retaining bolts and remove the drive belt from the pulleys. Remove the water pump pulley.
- Loosen and position the power steering pump mounting bracket and position it aside.
- Remove the four timing belt outer cover retaining bolts and remove the cover. Remove the crankshaft pulley and belt guide.
- Loosen the belt tensioner pulley assembly, then position a camshaft belt adjuster tool (T74P-6254-A or equivalent) on the tension spring rollpin and retract the belt tensioner away from the timing belt. Tighten the adjustment bolt to lock the tensioner in the retracted position.
- Remove the timing belt.
- Install the new belt over the crankshaft sprocket and then counterclockwise over the auxiliary and camshaft sprockets, making sure the lugs on the belt properly engage the sprocket teeth on the pulleys. Be careful not to rotate the pulleys when installing the belt.
- Release the timing belt tensioner pulley, allowing the tensioner to take up the belt slack. If the spring does not have enough tension to move the roller against the belt (belt hangs loose), it might be necessary to manually push the roller against the belt and tighten the bolt.
The spring cannot be used to set belt tension; a wrench must be used on the tensioner assembly.
- Rotate the crankshaft two complete turns by hand (in the normal direction of rotation) to remove the slack from the belt, then tighten the tensioner adjustment and pivot bolts to specifications. Refer to the necessary illustrations. Make sure the belt is seated properly on the pulleys and that the timing marks are still in alignment when No. 1 cylinder is again at TDC/compression.
- Install the crankshaft pulley and belt guide.
- Install the timing belt cover.
- Install the water pump pulley and fan blades. Install upper radiator hose if necessary. Refill the cooling system.
- Position the alternator and drive belts, then adjust and tighten it to specifications.
- Start the engine and check the ignition timing. Adjust the timing, if necessary.