- Inspect the camshaft journals and lobes for wear or scoring (1, 2).
- Wash the cylinder head in solvent.
- Inspect the cylinder head for cracks or other signs of damage.
- Inspect the camshaft bearing caps for wear, cracks and scoring.
- Inspect the camshaft bearing journals in the cylinder head for wear, cracks and scoring.
- If excessive wear or scoring is present, or if the cylinder head is cracked, replace the cylinder head with bearing caps.
- Measure the camshaft lobe height using a micrometer. The minimum measurement for the exhaust lobe height is 1.5693 inch on the No: 1 lobe and 1.5240 inch on the No: 2 lobe. The minimum measurement for the intake lobe height is 1.5925 inch on the No: 1 lobe and 1.5201 inch on the No: 2 lobe.
Replace the camshaft if any lobe is below the minimum.
- Place the camshaft (1) onto V-blocks. Measure the camshaft runout using a dial indicator. The maximum runout is 0.0012 inch. If the runout exceeds specifications, replace the camshaft.
Removal & Installation
- Before servicing the vehicle, refer to the precautions section.
Remove or disconnect the following:
Negative battery cable
Place a jack with a wooden block under the vehicle for support, then remove the 4 bolts and 2 nuts and remove the right side engine mount.
Remove the engine wire, on 1ZZ-FE engines:
- Remove the 5 clamps from the brackets.
- Detach the connectors.
- Remove the ignition coil connectors.
- Bolt and nut holding the engine wire.
Remove or disconnect the following:
Ignition coil assembly
- Set the No. 1 cylinder to Top Dead Center (TDC) of the compressor stroke as follows:
Remove the drive belt tensioner.
WARNINGDo not turn the crankshaft without the tensioner installed.
- Make sure the No. 1 cylinder is at TDC of the compression stroke.
Matchmark the timing chain and camshaft sprockets
Remove the 2 nuts and chain tensioner.
- Hold the camshafts with a wrench and loosen the camshaft set bolt.
Using several passes, gradually remove the bearing cap bolts from the No. 2 camshaft, in the proper sequence.
Remove the camshaft and timing gear as shown.
Using several passes, gradually remove the bearing cap bolts from the other camshaft, in the proper sequence.
Remove the camshaft while holding the timing chain.
WARNINGDo not let anything drop down into the timing chain cover while the camshafts are removed.
Tie the timing chain with a string as shown, to prevent it from dropping down into the timing chain cover.
Position the camshaft on the cylinder head, then install the timing chain on the cam timing gear, with the painted links aligned with the marks on the timing gear.
Check the front marks and numbers and torque the camshaft cap bolts, in sequence, to 10 ft. lbs. (13 Nm) for 1ZZ-FE engine, or to 14 ft. lbs. (19 Nm) for 2ZZ-GE engines.
- Put camshaft No. 2 on the cylinder head, with the painted links of the chain aligned with the mark on the timing gear.
- Tighten the camshaft gear set bolt temporarily.
Check the front marks and numbers and torque the camshaft cap bolts, in sequence, to 10 ft. lbs. (13 Nm). Install the No. 1 bearing cap and tighten to 17 ft. lbs. (23 Nm).
- Hold the camshaft secure with a wrench and tighten the set bolt to 40 ft. lbs. (54 Nm). Be careful not the damage the lifters.
- Check to be sure the matchmarks on the timing chain and cam sprockets, and the alignment of the pulley groove with the timing mark on the cover are still aligned.
Install the chain tensioner:
Make sure the O-ring is clean, then set the hook as shown.
Oil the tensioner, then install and tighten to 80 inch lbs. (9 Nm).
NOTEWhen installing the tensioner, set the hook again if the hook releases the plunger.
- Turn the crankshaft counterclockwise, and disconnect the plunger knock pin from the hook.
- Turn the crankshaft clockwise and check that the slipper is pushed by the plunger. If the plunger does not spring out, press the slipper into the chain tensioner with a screwdriver so that the hook is released from the knock pin and the plunger springs out.
- Make sure the O-ring is clean, then set the hook as shown.
- Check the valve clearance and make adjustments as needed.
Install or connect the following:
Belt tensioner. Tighten the nut to 21 ft. lbs. (29 Nm) and the bolt to 51 ft. lbs. (69 Nm).