Valve Clearance: Service and Repair

CAMSHAFT VALVE CLEARANCE


Inspection and Adjustment


INSPECTION
Perform inspection as follows after removal, installation or replacement of camshaft or valve-related parts, or if there is unusual engine conditions regarding valve clearance.
1. Remove rocker cover. Refer to Exploded View.
2. Measure the valve clearance with the following procedure:
a. Set No. 1 cylinder at TDC of its compression stroke.





- Rotate crankshaft pulley (2) clockwise and align TDC mark (without paint mark) (A) to timing indicator (1) on front cover.

B : White paint mark (Not use for service)






- At the same time, make sure that both intake and exhaust cam noses of No. 1 cylinder face inside as shown.

1 : Camshaft (INT)
2 : Camshaft (EXH)
Arrow Indicates Engine front

- If they do not face inside, rotate crankshaft pulley once more (360 degrees) and align as shown.





b. Use a feeler gauge, measure the clearance between valve lifter and camshaft.

Valve Clearance: Refer to Specifications






- Measure the valve clearances at locations marked "x" as shown in the table below [locations indicated with black arrow as shown] with a feeler gauge.

A : No. 1 cylinder compression TDC
Arrow Indicates Engine front










c. Rotate crankshaft pulley (2) one revolution (360 degrees) and align TDC mark (without paint mark) (A) to timing indicator (1) on front cover.

B : White paint mark (Not use for service)






- Measure the valve clearance at locations marked "x" as shown in the table below [locations indicated with black arrow as shown] with a feeler gauge.

A : No. 4 cylinder compression TDC
Arrow Indicates Engine front





3. If out of standard, perform adjustment procedure.

ADJUSTMENT
- Perform adjustment depending on selected head thickness of valve lifter.
1. Remove camshaft. Refer to Exploded View.
2. Remove valve lifters at the locations that are out of the standard.





3. Measure the center thickness of the removed valve lifters with a micrometer (A).
4. Use the equation below to calculate valve lifter thickness for replacement.










- Thickness of new valve lifter (B) can be identified by stamp mark (A) on the reverse side (inside the cylinder).
- Stamp mark "300" indicates 3.00 mm (0.118 in) in thickness.

NOTE:
Available thickness of valve lifter: 26 sizes range 3.00 to 3.50 mm (0.1181 to 0.1378 in) in steps of 0.02 mm (0.0008 in) (when manufactured at factory). Refer to Specifications.
5. Install the selected valve lifter.
6. Install camshaft. Refer to Exploded View.
7. Manually rotate crankshaft pulley a few rotations.
8. Make sure that valve clearances for cold engine are within specifications by referring to the specified values.
9. Install all removed parts in the reverse order of removal.
10. Warm up the engine, and check for unusual noise and vibration.