Nissan Maxima Service and Repair Manual: Camshaft Valve Clearance

Valve Clearance

CHECKING

NOTE:

• Perform inspection as follows after removal, installation or replacement of camshaft or valve related parts, or if there are unusual engine conditions regarding valve clearance.
• Check valve clearance while engine is cold and not running.

1. Remove the front air duct with air cleaner case, collectors, hoses, wires, harnesses, and connectors. Refer to EM-24, "Removal and Installation".
2. Remove the intake manifold collectors. Refer to EM-25, "Removal and Installation".
3. Remove the ignition coils and spark plugs. Refer to EM-42, "Exploded View".
4. Remove the rocker covers. Refer to EM-48, "Exploded View".
5. Set No.1 cylinder at TDC on its compression stroke.

• Align timing indicator with TDC mark (0) on crankshaft pulley.

• Check that the valve lifters on No.1 cylinder are loose and valve lifters on No.4 are tight. If not, turn the crankshaft one full revolution (360) and align as shown.

6. Check only the valve lifters as shown.

• Using a suitable tool, measure the clearance between the valve lifter and camshaft.
• Record any valve lifter clearance measurements which are out of specification. They will be used later to determine the required replacement valve lifter size.

  Valve Clearance for Checking (cold)

Intake : 0.26 - 0.34 mm (0.010 - 0.013 in)
Exhaust : 0.29 - 0.37 mm (0.011 - 0.015 in)

7. Turn crankshaft 240.
8. Set No.3 cylinder at TDC on its compression stroke.
9. Check only those valve lifters as shown.

10. Turn the crankshaft 240.
11. Set No.5 cylinder at TDC on its compression stroke.
12. Check only those valve lifters as shown.

13. If all valve lifter clearances are within specification, install the following components. If the valve lifter clearances are out of specification, adjust the valve lifter clearances.

• Intake manifold collectors
• Rocker covers
• All spark plugs
• All ignition coils

VALVE LIFTER ADJUSTING

CAUTION: Adjust valve lifter clearance while engine is cold.

NOTE:

• Perform adjustment by selecting the correct head thickness of the valve lifter (adjusting shims are not used).
• The specified valve lifter thickness is the dimension at normal temperatures. Ignore dimensional differences caused by temperature. Use specifications for hot engine condition to confirm valve lifter clearances.

1. Remove the camshaft. Refer to EM-76, "Removal and Installation".
2. Remove the valve lifter that was measured as being outside the standard specifications.
3. Measure the center thickness of the removed valve lifter using suitable tool as shown.

4. Use the equation below to calculate the replacement valve lifter thickness.

Valve lifter thickness calculation equation: t = t1 + (C1 - C2)
t = thickness of the replacement valve lifter
t1 = thickness of the removed valve lifter
C1 = measured valve lifter clearance
C2 = standard valve lifter clearance

• The thickness of the new valve lifter can be identified by the stamp mark on the reverse side (inside the valve lifter).
• Available thickness of the valve lifter (factory setting): 7.88 - 8.40 mm (0.3102 - 0.3307 in), in 0.02 mm (0.0008 in) increments, in 27 sizes (intake/exhaust). Refer to EM-130, "Camshaft".

5. Install the selected replacement valve lifter.
6. Install the camshaft. Refer to EM-76, "Removal and Installation".
7. Rotate the crankshaft a few turns by hand.
8. Confirm that the valve lifter clearances are within specification.
9. After the engine has been run to full operating temperature, confirm that the valve lifter clearances are within specification.

* Approximately 80C (176F)