Valve Clearance: Adjustments

Engine Mechanical System

VALVE CLEARANCE INSPECTION AND ADJUSTMENT
MLA(MECHANICAL LASH ADJUSTER)

NOTE:
Inspect and adjust the valve clearance when the engine is cold (Engine coolant temperature : (20°C ± 5°C [68°F ± 9°F]) and cylinder head is installed on cylinder block.

1. Remove the engine cover.




2. Remove the bolts(B) and timing belt upper cover(A).




3. Remove the cylinder head cover.
(1) Disconnect the spark plug cables and do not pull on the cable by force.

NOTE:
Pulling on or bending the cables may damage the conductor inside.




(2) Remove the PCV (Positive Crankcase Ventilation) hose(A) and the breather hose(B) from the cylinder head cover.




(3) Remove the accelerator cable(A) from the cylinder head cover.




(4) Loosen the cylinder head cover bolts(B) and then remove the cover(A) and gasket.




4. Set No. 1 cylinder to TDC/compression.
(1) Turn the crankshaft pulley and align its groove with the timing mark "T" of the lower timing belt cover.




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




5. Inspect the valve clearance.
(1) Check only the valve indicated as shown. [No. 1 cylinder : TDC/compression]. Measure the valve clearance.




A. Using a thickness gauge, measure the clearance between the tappet shim and the base circle of camshaft.
B. Record the out-of-specification valve clearance measurements. They will be used later to determine the required replacement adjusting shim.

Valve clearance
[Specification]
Engine coolant temperature : (20°C ± 5°C[68°F ± 9°F])
Intake : 0.20mm (0.0079in)
Exhaust : 0.28mm (0.0110in)
[Limit]
Intake : 0.12 - 0.28mm (0.0047 - 0.0110in)
Exhaust : 0.20 - 0.38mm (0.0079 - 0.0150in)
[Reference data]
Engine coolant temperature : 80°C[176°F]
Intake : 0.29mm (0.0114in)
Exhaust : 0.34mm (0.0134in)


(2) Turn the crankshaft pulley one revolution (360°) and align the groove with the timing mark "T" of lower timing belt cover.
(3) Check only valves indicated as shown. [No. 4 cylinder : TDC/compression]. Measure the valve clearance. )




6. Adjust the intake and exhaust valve clearance.
(1) Turn the crankshaft so that the cam lobe of the camshaft on the adjusting valve is upward.
(2) Using the SST(09220 - 2D000), press down the valve lifter and place the stopper between the camshaft and valve lifter and remove the special tool.




(3) Remove the adjusting shim with a small screw driver(A) and magnet(B).




(4) Measure the thickness of the removed shim using a micrometer.




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

Valve clearance
(Engine coolant temperature : 20°C ± 5°C[68°F ± 9°F])
T : Thickness of removed shim
A : Measured valve clearance
N : Thickness of new shim

Intake : N = T + [A - 0.20mm(0.0079in)]
Exhaust : N = T + [A - 0.28mm(0.0110in)]


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

NOTE:
Shims are available in 20 size increments of 0.04mm (0.0016in) from 2.00mm (0.0787in) to 2.76mm (0.1087in)

(7) Place a new adjusting shim on the valve lifter.
(8) Using the SST(09220 - 2D000), press down the valve lifter and remove the stopper.
(9) Recheck the valve clearance.

Valve clearance
(Engine coolant temperature : 20°C ± 5°C[68°F ± 9°F])
[Specification]
Intake : 0.20mm (0.0079in)
Exhaust : 0.28mm (0.0110in)
[Limit] (After adjusting valve clearance)
Intake : 0.17 - 0.23mm (0.0067 - 0.0091in)
Exhaust : 0.25 - 0.31mm (0.0098 - 0.0122in)