Valve Clearance
CAUTION:
Check and adjust valve clearance with engine cold.
- Disconnect negative battery cable. Remove valve cover and gaskets. Rotate crankshaft until No. 1 cylinder is at TDC of compression stroke. Ensure timing mark on crankshaft pulley aligns with zero mark on timing belt cover.
- Valve lifters should be loose on No. 1 cylinder, and tight on No. 4 cylinder. If lifters on both valves are not as specified, rotate crankshaft one revolution (360 degrees) and realign crankshaft pulley mark.
- Using a feeler gauge, measure and record clearance between camshaft lobe and adjuster shim on intake valves of cylinders No. 1 and 2, and exhaust valves of cylinders No. 1 and 3. SeeVALVE CLEARANCE SPECIFICATIONS table. To adjust valve clearance if not within specification, go to step 5). If valve clearance is within specifications, go to next step.
- Rotate crankshaft one revolution (360 degrees). Using a feeler gauge, measure and record clearance on intake valves of cylinders No. 3 and 4, and exhaust valves of cylinders No. 2 and 4. To adjust valve clearance if not within specification, go to next step. See VALVE CLEARANCE SPECIFICATIONS table.
- Install Lifter Spring Compressor (J-39871-1) between camshaft and lifter to push lifter downward. See Fig 1 . Insert Lifter Detainer (J-39871-2) between camshaft and lifter. Ensure bottom edge of lifter detainer is positioned on lifter, not on adjuster shim. See Fig 1 . This will hold lifter away from camshaft.
- Remove lifter spring compressor. Using a small screwdriver and magnet, remove adjuster shim. Replacement adjuster shim thickness can be determined by using adjuster shim charts. See Fig 2
and Fig 3
. Adjuster shim thickness may also be determined by using the following formula:
For intake valve shim; N = T + A - .008" (.20 mm).
For exhaust valve shim; N = T + A - .010" (.25 mm).
- N = Thickness of new replacement adjuster shim.
- T = Thickness of old removed adjuster shim.
- A = Measured valve clearance.
- Shims are available in 16 sizes of .1004-.1299" (2.55-3.30 mm) in increments of .002" (.050 mm). To install NEW adjuster shim, depress valve spring using lifter spring compressor. Install adjuster shim. Remove lifter detainer and spring compressor. Ensure adjusted valve clearance is within specification. To install remaining components, reverse removal procedure.
VALVE CLEARANCE SPECIFICATIONS
| Application | In. (mm) | ||
|---|---|---|---|
| Intake | (1) .006-.010 (.15-.25) | ||
| Exhaust | (1) .010-.014 (.25-.35) | ||
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