Valve Clearance: Testing and Inspection

Valve Clearance Inspection And Adjustment

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

1. Remove the cylinder head cover.
2. 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 chain cover.




(2) Check that the TDC marks (A) of the CVVT sprockets are in straight line on the cylinder head surface as shown in the illustration.
If not, turn the crankshaft one revolution (360°)




3. Inspect the valve clearance.
(1) Check only the valve indicated as shown. Measure the valve clearance.




A. Using a thickness gauge, measure the clearance between the tappet 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 tappet.

Valve clearance
Specification
Engine coolant temperature : 20°C [68°F]
Limit
Intake : 0.10 - 0.30mm (0.0039 - 0.0118in.)
Exhaust : 0.20 - 0.40mm (0.0079 - 0.0157in.)

(2) Turn the crankshaft pulley one revolution (360°) and align the groove with timing mark "T" of the timing chain cover.
(3) Check only valves indicated as shown. Measure the valve clearance.




4. Adjust the intake and exhaust valve clearance.
(1) Set the No.1 cylinder to the TDC/compression.
(2) Mark the timing chains (A) on the timing marks of the CVVT sprockets.




(3) Turn the crankshaft pulley 15° clockwise.
(4) Remove the service hole bolt(A) of the timing chain cover.





CAUTION:
The bolt must not be reused once it has been assembled.

(5) Insert the SST (09240-2G000) in the service hole of the timing chain cover and release the ratchet.








A. Compress the center rod (A) by pulling out the end plate (B).




B. Insert a ratchet holder through the service hole by turning the holder body (A) clockwise until the end of the center rod touches the tensioner ratchet.




C. Turn the holder body (A) one full turn counterclockwise.




D. Turn the end plate (A) of the center rod (less than one turn) clockwise or counterclockwise until the end plate goes into the groove (B) of holder body.





NOTE:
When turning the end plate, hold the body not to rotate with the end plate.

E. Turn the holder body (A) (less than one turn) counterclockwise until the rotation stops.
F. Tighten the lock nut (B).




(6) Remove the front camshaft bearing cap.
(7) Remove the exhaust camshaft bearing cap and exhaust camshaft.
(8) Remove the intake camshaft bearing cap and intake camshaft.

CAUTION:
When disconnecting the timing chain from the CVVT sprocket, tie or hold the timing chain so it does not fall into the timing cover.

(9) Tie down timing chain so that it doesn't move.

CAUTION:
Be careful not to drop anything inside timing chain cover.

(10) Measure the thickness of the removed tappet using a micrometer.




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

Valve clearance [Engine coolant temperature : 20°C(68°F)]
T : Thickness of removed tappet
A : Measured valve clearance
N : Thickness of new tappet
Intake : N = T + [A - 0.20mm (0.0079in.)]
Exhaust : N = T + [A - 0.30mm (0.0118in.)]

(12) Select a new tappet with a thickness as close as possible to the calculated value.

NOTE:
Shims are available in 47 size increments of 0.015mm (0.0006in.) from 3.00mm (0.118in.) to 3.690mm (0.1452in.)

(13) Place the new tappet on the valve stem/spring.
(14) Hold the timing chain, and install the intake camshaft and CVVT assembly.
(15) Align the timing marks (A) on the timing chains and CVVT sprockets.




(16) Install the exhaust camshaft and CVVT assembly.
(17) Install the front bearing cap.
(18) Install the service hole bolt after removing the SST from the service hole.

Tightening torque :
11.8 - 14.7N.m (1.2 - 1.5kgf.m, 8.7 - 10.8lb-ft)

NOTE:
To remove ratchet holder, loosen the lock nut and pull out the center rod.

(19) Turn the crankshaft two turns in the operating direction(clockwise), and then check that the TDC marks (A) of the CVVT sprockets are in straight line on the cylinder head surface.




(20) Recheck the valve clearance.

Valve clearance [Engine coolant temperature : 20°C(68°F)]
[Specification]
Intake : 0.17 - 0.23mm (0.0067 - 0.0090in.)
Exhaust : 0.27 - 0.33mm (0.0106 - 0.0129in.)