Engine Mechanical (Coupe): Adjustments Nissan Altima L33

Tension Adjustment

1. Belt tension is not manually adjustable, it is automatically adjusted by the drive belt auto-tensioner.

Scheme 524

1. Remove the fender protector side cover RH. Refer to " «REMOVAL AND INSTALLATION»(ref-592019-S24442268552014010800000) ".
2. Securely hold the hexagonal part in pulley center of drive belt auto-tensioner, move in the direction of arrow (loosening direction of tensioner) using Tool. Tool number: - (J-46535) WARNING: Avoid placing hand in a location where pinching may occur if the holding tool accidentally comes off. CAUTION: Do not loosen the auto-tensioner pulley bolt. (Do not turn it counterclockwise.) If turned counterclockwise, the complete auto-tensioner must be replaced as a unit, including pulley.
3. Insert a rod approximately 6 mm (0.24 in) in diameter through the rear of tensioner into retaining boss to lock tensioner pulley. Leave tensioner pulley arm locked until drive belt is installed again.
4. Loosen drive belt from water pump pulley and then remove it from the other pulleys.

ADJUSTMENT

1. Perform adjustment depending on selected head thickness of valve lifter.
2. The specified valve lifter thickness is the dimension at normal temperatures. Ignore dimensional differences caused by temperature. Use the specifications for hot engine condition to adjust.

Scheme 525

Scheme 526

1. Remove camshaft. Refer to " «REMOVAL AND INSTALLATION»(ref-592016-S00554203142014010800000) ".
2. Remove the valve lifters at the locations that are outside the standard.
3. Measure the center thickness of the removed valve lifters with a micrometer.
4. Use the equation below to calculate valve lifter thickness for replacement. Valve lifter thickness calculation. t = t1 + (C1 - C2) t = Thickness of replacement valve lifter. t1 = Thickness of removed valve lifter. C1 = Measured valve clearance. C2 = Standard valve clearance. Thickness of a new valve lifter can be identified by stamp marks on the reverse side (inside the cylinder). Stamp mark 696 indicates a thickness of 6.96 mm (0.2740 in) Available thickness of valve lifter: 26 sizes with a range of 7.88 to 8.38 mm (0.3102 to 0.3299 in), in steps of 0.02 mm (0.0008 in), when assembled at the factory.
5. Install the selected valve lifter.
6. Install camshaft.
7. Manually turn crankshaft pulley a few turns.
8. Check that valve clearances for cold engine are within specifications, by referring to the specified values.
9. After completing the repair, check valve clearances again with the specifications for warmed engine. Use a feeler gauge to measure the clearance between the valve and camshaft. Make sure the values are within specifications. Valve clearance standard: Cold Intake: 0.24 - 0.32 mm (0.009 - 0.013 in) Exhaust: 0.26 - 0.34 mm (0.010 - 0.013 in) Hot* Intake: 0.304 - 0.416 mm (0.012 - 0.016 in) Exhaust: 0.308 - 0.432 mm (0.012 - 0.017 in)

* Approximately 80°C (176°F)

Scheme 527

Scheme 528

1. Warm up the engine to full operating temperature.
2. Release the fuel pressure. Refer to " «INSPECTION»(ref-592022-S08111032412014010800000) " (California), " «INSPECTION»(ref-592023-S21357902862014010800000) " (Except California).
3. Remove the ignition coil and spark plug from each cylinder. Refer to " «REMOVAL AND INSTALLATION»(ref-592016-S14052902852014010800000) ".
4. Connect engine tachometer (not required in use of CONSULT).
5. Disconnect the fuel injector harness connector to avoid any residual fuel injection during the measurement.
6. Install the compression tester with the adapter into the spark plug hole. Use compression tester whose end (rubber portion) is smaller than 20 mm (0.79 in) in diameter. Otherwise, it may be caught by cylinder head during removal.
7. With the accelerator pedal fully depressed, turn the ignition switch to the "START" position to crank over the engine. When the gauge pointer stabilizes, read the compression pressure and engine RPM. Perform these steps to check each cylinder. Unit: kPa (kg/cm 2 , psi)/rpm Standard Minimum Difference limit between cylinders 1, 250 (12.8, 181.3)/250 1, 060 (10.8, 153.7)/250 100 (1.0, 14)/250 CAUTION: Always use a fully charged battery to obtain specified engine cranking speed. If the engine speed is out of specified RPM range, check the battery. Check engine speed again with a fully charged battery. If compression pressure is below minimum value, check valve clearances and parts associated with combustion chamber (valve, valve seat, piston, piston ring, cylinder bore, cylinder head, cylinder head gasket). After the checking, measure compression pressure again. If some cylinders have low compression pressure, pour small amount of engine oil into the spark plug hole of the cylinder to re-check it for compression. If the added engine oil improves the compression, the piston rings may be worn or damaged. Check the piston rings and replace if necessary. If the compression pressure remains at low level despite the addition of engine oil, the valves may be malfunctioning. Check the valves for damage. Replace the valve or valve seat accordingly. If two adjacent cylinders have respectively low compression pressure and their compression remains low even after the addition of engine oil, the head gasket is leaking. In such a case, replace the cylinder head gasket.
8. Install spark plug, ignition coil and harness connectors.

Scheme 529

1. Perform adjustment depending on selected head thickness of valve lifter.
2. The specified valve lifter thickness is the dimension at normal temperatures. Ignore dimensional differences caused by temperature. Use the specifications for hot engine condition to adjust.

Scheme 530

Scheme 531

1. Remove camshaft. Refer to " «REMOVAL AND INSTALLATION»(ref-592016-S00554203142014010800000) ".
2. Remove the valve lifters at the locations that are outside the standard.
3. Measure the center thickness of the removed valve lifters with a micrometer.
4. Use the equation below to calculate valve lifter thickness for replacement. Valve lifter thickness calculation. t = t1 + (C1 - C2) t = Thickness of replacement valve lifter. t1 = Thickness of removed valve lifter. C1 = Measured valve clearance. C2 = Standard valve clearance. Thickness of a new valve lifter can be identified by stamp marks on the reverse side (inside the cylinder). Stamp mark 696 indicates a thickness of 6.96 mm (0.2740 in) Available thickness of valve lifter: 26 sizes with a range of 7.88 to 8.38 mm (0.3102 to 0.3299 in), in steps of 0.02 mm (0.0008 in), when assembled at the factory.
5. Install the selected valve lifter.
6. Install camshaft.
7. Manually turn crankshaft pulley a few turns.
8. Check that valve clearances for cold engine are within specifications, by referring to the specified values.
9. After completing the repair, check valve clearances again with the specifications for warmed engine. Use a feeler gauge to measure the clearance between the valve and camshaft. Make sure the values are within specifications. Valve clearance standard: Cold Intake: 0.24 - 0.32 mm (0.009 - 0.013 in) Exhaust: 0.26 - 0.34 mm (0.010 - 0.013 in) Hot* Intake: 0.304 - 0.416 mm (0.012 - 0.016 in) Exhaust: 0.308 - 0.432 mm (0.012 - 0.017 in)

*: Approximately 80°C (176°F)

Scheme 532

1. Disconnect intake valve timing control solenoid valve connector.
2. Remove intake valve timing control solenoid valve bolt.
3. Remove intake valve timing control solenoid valve (1) and O-ring (2) from intake valve timing control solenoid valve cover. CAUTION: Do not reuse O-ring.