Valve Clearance: Service and Repair
Valve Clearance Check1. Remove the valve covers.
2. Remove the spark plugs.
3. NOTE: The engine will have to be rotated with the crankshaft pulley bolt to bring each valve to base circle.
NOTE: The valve clearance must be measured with the camshaft at base circle.
Measure and record all valve clearances.
4. If the valve clearances are out of specification, refer to Valve Clearance Adjustment.
5. To assemble, reverse the inspection procedure.
Valve Clearance Adjustment
1. Remove the timing chains.
2. NOTE: Measure each valve clearance at base circle before removing the camshafts. The shims are not repairable with the camshafts in place. Failure to measure all clearances prior to removing the camshafts will cause unnecessary repetition of the procedure.
Use a feeler gauge to measure each valve clearance and record its location.
3. Remove the camshafts.
4. Remove the shims.
5. NOTE: The shims are marked for thickness; example: 2.22 mm = 222 on shim.
NOTE: The corrected shims allow the following valve clearances.
^ Intake valve clearance: 0.18 - 0.22 mm (0.00709 - 0.00866 inch)
^ Exhaust valve clearance: 0.33 - 0.38 mm (0.0128 - 0.0148 inch)
NOTE: A midrange clearance is the most desirable:
^ Intake: 0.20 mm (0.00787 inch)
^ Exhaust: 0.35 mm (0.014 inch)
NOTE: Select shims using this formula: required shim thickness = measured clearance plus the base shim thickness minus most desirable clearance.
Select shims and mark the installation location.
6. Install new shims.
7. Install the camshaft.
8. Measure the new valve clearances.
9. Install the timing chains.