Valve Clearance: Adjustments

VALVE CLEARANCE INSPECTION AND ADJUSTMENT

HINT: Inspect and adjust the valve clearance when the engine is cold.

1. REMOVE CYLINDER HEAD COVER

(a) Disconnect the following wires and clamps:
(1) Alternator connector
(2) Alternator wire
(3) Oil pressure switch connector
(4) Two wire clamps

(b) Remove the two bolts and wire harness protector.

(d) Disconnect the high - tension cords at the rubber boot. Do not pull on the high-tension cords.

NOTICE: Pulling on or bending the cords may damage the conductor inside.

(e) Disconnect the PCV hoses from the cylinder head cover.

(f) Remove the four cap nuts, seal washers, cylinder head cover and gasket.

2. SET NO.1 CYLINDER TO TDC/COMPRESSION

(a) Turn the crankshaft pulley and align its groove with the timing mark "0" of the No.1 timing belt cover.

(b) Check that the hole of the camshaft timing pulley is aligned with the timing mark of the bearing cap. If not, turn the crankshaft one revolution (360°).

3. INSPECT VALVE CLEARANCE

(a) Check only the valves indicated.
- Using a thickness gauge, measure the clearance between the valve lifter and camshaft.
- Record the out - of - specification valve clearance measurements. They will be used later to determine the required replacement adjusting shim.

Valve clearance (Cold):
Intake: 0.15 - 0.25 mm (0.006 - 0.010 in.)
Exhaust: 0.25 - 0.35 mm (0.010 - 0.014 in.)

(b) Turn the crankshaft pulley one revolution (3600) and align the its groove with timing mark "0" of the No.1 timing belt cover.

(c) Check only the valves indicated as shown. Measure the valve clearance. (See procedure in step (a))

4. ADJUST INTAKE VALVE CLEARANCE
A. Remove intake camshaft

NOTICE: Since the thrust clearance of the camshaft is small. the camshaft must be kept level while it is being removed. If the camshaft is not kept level, the portion of the cylinder head receiving the shaft thrust may crack or be damaged. causing the camshaft to seize or break. To avoid this. the following steps should be carried out.

(a) Turn the crankshaft pulley so that the hole in the sub-gear (which sets the sub-gear to the camshaft drive gear) comes up.

HINT: The above state allows the No.1 and No.3 cylinder cam lobes of the intake camshaft to push their valve lifters evenly.

(b) Remove the two bolts and No.1 bearing cap.

(c) Secure the intake camshaft sub-gear to the drive gear with a service bolt.

Recommended service bolt:
Thread diameter: 6 mm
Thread pitch: 1.0 mm
Bolt length: 16 - 20 mm (0.63 - 0.79 in.)

HINT: When removing the camshaft, make sure that the torsional spring force of the sub-gear has been eliminated by the above operation.

(d) Uniformly loosen and remove the eight bearing cap bolts in several passes, in the sequence shown.
(e) Remove the four bearing caps and camshaft.

HINT: If the camshaft is not being lifted out straight and level, reinstall the No.3 bearing cap with the two bolts. Then alternately loosen and remove the bearing cap bolts with the camshaft gear pulled up

NOTICE: Do not pry on or attempt to force the camshaft with a tool or other object.

B. Remove adjusting shim

Remove the adjusting shim with a small screwdriver.

C. Determine the replacement adjusting shim size by following Formula or Charts:

(a) Using a micrometer, measure the thickness of the removed shim.
(b) Calculate the thickness of a new shim so that the valve clearance comes within specified value.

T: Thickness of removed shim
A: Measured valve clearance
N: Thickness of new shim

Intake: N = T + (A - 0.20 mm (0.008 in.))

(c) Select a new shim with a thickness as close as possible to the calculated value.

HINT: Shims are available in 16 sized in increments of 0.05 mm (0.0020 in.), from 2.55 mm (1.0039 in.) to 3.30 mm (0.1299 in.).

D. Install new adjusting shim

Place a new adjusting shim on the valve lifter.

E. Install intake camshaft

NOTICE: Since the thrust clearance of the camshaft is small, the camshaft must be kept level while it is being removed. If the camshaft is not kept level, the portion of the cylinder head receiving the shaft thrust may crack or be damaged. causing the camshaft to seize or break. To avoid this, the following steps should be carried out.

(a) Turn the crankshaft pulley, set the intake camshaft so the knock pin is slightly above the top of the cylinder head.

(b) Apply MP grease to the thrust portion of the camshaft.
(c) Engage the intake camshaft gear to the exhaust camshaft gear by matching the assembly installation mark on each gear.

NOTICE: There are also timing marks (for TDC) on each gear as shown in the illustration. Do not use these marks.

(d) Roll down the intake camshaft onto the bearing journals while engaging gears with each other.

HINT: The above angle allows the No.1 and No.3 cylinder cam lobes of the intake camshaft to push their valve lifters evenly.

(e) Install the four bearing caps in their proper locations.

(f) Apply a light coat of engine oil on the threads and under the heads of the bearing cap bolts.
(g) Install and uniformly tighten the eight bearing cap bolts in several passes, in the sequence shown.
Torque: 13 N.m (130 kgf.cm, 9 ft.lbf)

(h) Remove the service bolt.

(i) Install the No.1 bearing cap with the arrow mark facing forward.

NOTICE: If the No.1 bearing cap does not fit properly, push the camshaft gear backwards by prying apart the cylinder head and camshaft gear with a screwdriver.

(j) Apply a light coat of engine oil on the threads and under the heads of the bearing cap bolts.
(k) Install and alternately tighten the two bearing cap bolts in several passes.
Torque: 13 N.m (130 kgf.cm, 9 ft.lbf)

F. Recheck valve clearance

5. ADJUST EXHAUST VALVE CLEARANCE
A. Remove adjusting shim

(a) Turn the crankshaft so that the cam lobe of the camshaft on the adjusting valve upward.
(b) Position the notch of the valve lifter facing the front of the vehicle.

(c) Using SST (A), press down the valve lifter and place SST (B) between the camshaft and valve lifter. Remove SST (A).
SST: 09248-55020 (09248-05011, 09248-05021)

HINT:
- Apply SST (B) at slight angle on the side marked with "9", at the position shown in the illustration.
- When SST (B) is inserted too deeply, it will get pinched by the shim. To prevent it from being stuck, insert it shallowly from the intake side, at a slight angle.

- The shape of the cam makes it difficult to insert SST (B), from the intake side to the No.3 rear. For this shim, it is best approached from the exhaust side instead.

(d) Remove the adjusting shim with a small screwdriver and magnetic finger.

B. Determine replacement adjusting shim size by following Formula or Charts:

(a) Using a micrometer, measure the thickness of the removed shim.
(b) Calculate the thickness of a new shim so that the valve clearance comes within specified value.

T: Thickness of removed shim
A: Measured valve clearance
N: Thickness of new shim

Exhaust: N = T + (A - 0.30 mm (0.012 in.))

(c) Select a new shim with a thickness as close as possible to the calculated value.

HINT: Shims are available in 16 sizes, in increments of 0.05 mm (0.0020 in.), from 2.55 mm (1.0039 in.) to 3.30 mm (0.1299 in.).

C. Install new adjusting shim

(a) Place a new adjusting shim on the valve lifter.
(b) Using SST (A), press down the valve lifter and remove SST (B).
SST: 09248-55020 (09248-05011. 09248-05021)

D. Recheck valve clearance

6. INSTALL CYLINDER HEAD COVER
(a) Remove any old packing (FIPG) material.

(b) Apply seal packing to the cylinder head as shown in the illustration.
Seal packing: Part No.08826-00080 or equivalent
(c) Install the gasket to the cylinder head cover.

(d) Install the cylinder head cover with the four seal washers and cap nuts.
Torque. 5.9 N.m (60 kgf.cm, 52 in.lbf)

(e) Connect the PCV hoses to the cylinder head cover.
(f) Connect the four high-tension cords to the spark plugs.

(g) Install the engine wire harness and protector with the two bolts.
(h) Connect the following wires and clamps:

(1) Alternator connector
(2) Alternator wire
(3) Oil pressure switch connector
(4) Two wire clamps