Valve Clearance: Adjustments

INSPECTION AND ADJUSTMENT OF VALVE CLEARANCE

HINT: Adjust the valve clearance while the engine is cold.


1. REMOVE NO.3 TIMING BELT COVERS
2. DISCONNECT HIGH-TENSION CORDS FROM SPARK PLUGS
3. REMOVE CYLINDER HEAD COVERS





4. SET NO.1 CYLINDER TO TDCICOMPRESSION
(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 timing marks of the camshaft timing pulleys and timing belt rear plates are aligned.
If not, turn the crankshaft one revolution (3600) and align the mark as above.

5. INSPECT VALVE CLEARANCE





(a) Check only those valves indicated in the figure.

- Using a feeler gauge, measure the clearance between the valve lifter and camshaft.

- Record 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 one revolution (3600), and align the mark as above. (See procedure step 5 (a))





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





6. ADJUST VALVE CLEARANCE

(a) Remove the adjusting shim.

- Turn the crankshaft to position the cam lobe of the camshaft on the adjusting valve upward.

- Press down the valve lifter with SST (A), and place SST (B) between the camshaft and valve lifter flange. Remove SST (A).

SST 09248-55011





- Using compressed air and magnetic finger, remove the adjusting shim by blowing air into the shim hole.

(b) Determine the replacement adjusting shim size following the Formula or Charts:





- Using a micrometer, measure the thickness of the removed shim.

- Calculate the thickness of a new shim so that the valve clearance comes within specified value.

T Thickness of used shim

A Measured valve clearance

N Thickness of new shim

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

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

- Select a new shim with a thickness as close as p05sible to the calculated values.

HINT: Shims are available in seventeen sizes of 0.05 mm

(0.0020 in.), from 2.50 mm (0.0984 in.) to 3.30 mm

(0.1299 in.).

(c) Install a new adjusting shim.

- Place a new adjusting shim on the valve lifter.

- Press down the valve lifter with SST (A), and remove SST (B).

SST 09248-55011





(d) Recheck the valve clearance.

7. REINSTALL CYLINDER HEAD COVERS
8. RECONNECT HIGH-TENSION CORDS TO SPARK PLUGS
9. REINSTALL NO.3 TIMING BELT COVERS