Engine Mechanical: Adjustments Nissan Quest IV

Tension Adjustment

Refer to " DRIVE BELT ".

ADJUSTMENT

1. Perform adjustment depending on selected head thickness of valve lifter.

Scheme 7

Scheme 8

1. Measure the valve clearance. Refer to " «INSPECTION»(ref-672620-S30051580492014112400000) ".
2. Remove camshaft. Refer to " «EXPLODED VIEW»(ref-672620-S27549891992014112400000) ".
3. Remove valve lifters at the locations that are out of the standard.
4. Measure the center thickness of the removed valve lifters with a micrometer (A).
5. Use the equation below to calculate valve lifter thickness for replacement. Valve lifter thickness calculation: t = t1 + (C1 - C2) t = Valve lifter thickness to be replaced t1 = Removed valve lifter thickness C1 = Measured valve clearance C2 = Standard valve clearance: Intake: 0.30 mm (0.012 in) Exhaust: 0.33 mm (0.013 in) Thickness of new valve lifter can be identified by stamp marks on the reverse side (inside the cylinder). Stamp mark 788P indicates 7.88 mm (0.3102 in) in thickness. Available thickness of valve lifter: 27 sizes with range 7.88 to 8.40 mm (0.3102 to 0.3307 in) in steps of 0.02 mm (0.0008 in) (when manufactured at factory). Refer to " «CAMSHAFT»(ref-672620-S10622127142014112400000) ".
6. Install selected valve lifter.
7. Install camshaft. Refer to " «EXPLODED VIEW»(ref-672620-S27549891992014112400000) ".
8. Manually turn crankshaft pulley a few turns.
9. Check that the valve clearances for cold engine are within the specifications by referring to the specified values.
10. Install all removal parts in the reverse order of removal.
11. Warm up the engine, and check for unusual noise and vibration.

Scheme 9

Scheme 10

1. Warm up engine thoroughly. Then, stop it.
2. Release fuel pressure. Refer to " «WORK PROCEDURE»(ref-672625-S22980190582014112400000) ".
3. Remove ignition coil and spark plug from each cylinder. Refer to " «EXPLODED VIEW»(ref-672620-S14189085292014112400000) ".
4. Connect engine tachometer (not required in use of CONSULT).
5. Install compression gauge with an adapter (commercial service tool) onto spark plug hole. Use the adapter whose picking up end inserted to spark plug hole is smaller than 20 mm (0.79 in) in diameter. Otherwise, it may be caught by cylinder head during removal.
6. With accelerator pedal fully depressed, turn ignition switch to "START" for cranking. When the gauge pointer stabilizes, read the compression pressure and the engine rpm. Perform these steps to check each cylinder. Compression pressure: Refer to " «GENERAL SPECIFICATION»(ref-672620-S39861978532014112400000) ". CAUTION: Always use a fully charged battery to obtain the specified engine speed. If the engine speed is out of the specified range, check battery liquid for proper gravity. Check the engine speed again with normal battery gravity. 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 cylinder has low compression pressure, pour small amount of engine oil into the spark plug hole of the cylinder to recheck it for compression. If the added engine oil improves the compression, piston rings may be worn out or damaged. Check piston rings and replace if necessary. If the compression pressure remains at low level despite the addition of engine oil, valves may be malfunctioning. Check valves for damage. Replace 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, cylinder head gaskets are leaking. In such a case, replace cylinder head gaskets.
7. After inspection is completed, install removed parts.
8. Start the engine, and check that the engine runs smoothly.
9. Perform trouble diagnosis. If DTC appears, erase it. Refer to " «DESCRIPTION»(ref-672625-S20417442512014112400000) ".

Scheme 11

Scheme 12

1. Remove air duct (inlet). Refer to " «EXPLODED VIEW»(ref-672620-S30704453622014112400000) ".
2. Remove engine cover mounting bolts (A) and (B).
3. Draw and pull out engine cover from engine cover mounting bolts (C) and (D). CAUTION: Pull engine cover from mounting bolt (D) holding with hand the position (E) as shown in the figure below.
4. Remove engine cover mounting bolts (C) and (D) if necessary.