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. 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 (1) clockwise and align TDC mark (no paint) (B) to timing indicator (A) on front cover.










- At the same time, check that both intake and exhaust cam noses of No. 1 cylinder face inside (black arrow ) as shown in the figure.





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





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





- By referring to the figure, measure the valve clearances at locations marked "x" as shown in the table below [locations indicated with (black arrow) in the figure] with a feeler gauge.











c.Set No. 4 cylinder at TDC of its compression stroke.






- Rotate crankshaft pulley (1) one revolution (360 degrees) and align TDC mark (no paint) (B) to timing indicator (A) on front cover.










- By referring to the figure, measure the valve clearance at locations marked "x" as shown in the table below [locations indicated with (black arrow ) in the figure] with a feeler gauge.











3.If out of standard, perform adjustment. Refer to "ADJUSTMENT".

ADJUSTMENT

- Perform adjustment depending on selected head thickness of valve lifter.
1.Remove camshaft. 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 "302" indicates 3.02 mm (0.1189 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). Camshaft.
5.Install the selected valve lifter.
6.Install camshaft. Exploded View.
7.Install timing chain and related parts. Exploded View.
8.Manually rotate crankshaft pulley a few rotations.
9.Check that the valve clearances is within the standard. Refer to "INSPECTION".
10.Install remaining parts in the reverse order of removal.
11.Warm up the engine, and check for unusual noise and vibration.