VALVE ADJUSTING Nissan Altima L32 facelift

VALVE ADJUSTING

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 clearances.

Scheme 467

Scheme 468

1. Remove the camshaft.
2. Remove the valve lifter that was measured as being outside the standard specifications.
3. Measure the center thickness of the removed lifter with a micrometer, as shown in the figure.
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 lifter t1 = thickness of the removed lifter C1 = measured valve clearance C2 = standard valve clearance The thickness of the new valve lifter can be identified by the stamp mark on the reverse side (inside the 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 " «CYLINDER HEAD»(ref-388121-S08927126932011030100000) ".
5. Install the selected replacement valve lifter.
6. Install the camshaft.
7. Rotate the crankshaft a few turns by hand.
8. Confirm that the valve clearances are within specification.
9. After the engine has been run to full operating temperature, confirm that the valve clearances are within specification. VALVE CLEARANCE SPECIFICATION Standard Valve Clearance Cold Hot (1) (reference data) Intake 0.26 - 0.34 mm (0.010 - 0.013 in) 0.304 - 0.416 mm (0.012 - 0.016 in) Exhaust 0.29 - 0.37 mm (0.011 - 0.015 in) 0.308 - 0.432 mm (0.012 - 0.017 in) (1) Approximately 80°C (176°F)

Scheme 469

1. Run the engine until it reaches normal operating temperature.
2. Turn the ignition switch to OFF.
3. Release fuel pressure and leave the fuel pump electrically disconnected. Refer to " «INSPECTION»(ref-388123-S40979356942011030100000) ".
4. Remove all six spark plugs. Refer to " «REMOVAL AND INSTALLATION»(ref-388121-S17219782092011030100000) ".
5. Attach a compression tester to No. 1 cylinder.
6. Depress accelerator pedal fully to keep the electric throttle control actuator butterfly-valve wide open to maximize air intake flow.
7. Crank the engine and record the highest gauge indication.
8. Repeat the measurement on each cylinder (steps 5 - 7 ). Always use a fully-charged battery to obtain specified engine speed. ENGINE SPEED SPECIFICATION Unit: kPa (kg/cm 2 , psi)/rpm Standard Minimum Difference limit between cylinders 1,275 (13.0, 185)/300 981 (10.0, 142)/300 98 (1.0, 14)/300
9. If compression in one or more cylinders is low: Pour a small amount of engine oil into cylinders through the spark plug holes. Retest compression (steps 5 - 8 ). If adding oil helps raise compression pressure, then the piston rings may be worn or damaged. If so, replace piston rings after checking piston. If the pressure stays low, a valve may be sticking or is seating improperly. Inspect and repair the valve and/or valve seat. Refer to " «CAMSHAFT»(ref-388121-S31281482102011030100000) ". If the valve and/or valve seat is damaged excessively, replace as necessary. If compression stays low in two or more cylinders that are next to each other: The cylinder head gasket may be leaking. Both cylinders may have valve component damage. Inspect and repair as necessary.

Scheme 470