Part 3

3MZ-FE ENGINE UNIT

COMPONENTS:

DISASSEMBLY (STEPS 73-91)
73. REPAIR VALVE SEATS

NOTICE: Releasing the seat-cutter pressure gradually helps to make smoother valve seat faces.

a. If the seating is too high on the valve face, use 30° and 45° cutters to correct the seat.

b. If the seating is too low on the valve face, use 60° and 45° cutters to correct the seat.
c. Hand rub the valve and valve seat with an abrasive compound.
d. Recheck the valve seating position.

74. INSPECT VALVE LIFTER
a. Using a micrometer, measure the lifter diameter.
Lifter diameter: 30.966 to 30.976 mm (1.2191 to 1.2195 inch)

75. INSPECT VALVE LIFTER OIL CLEARANCE
a. Using a caliper gauge, measure the lifter bore diameter of the cylinder head.
Lifter bore diameter: 31.009 to 31.025 mm (1.2208 to 1.2215 inch)
b. Subtract the lifter diameter measurement from the lifter bore diameter measurement.
Standard oil clearance: 0.033 to 0.059 mm (0.0013 to 0.0023 inch)
Maximum oil clearance: 0.07 mm (0.0028 inch)
76. INSPECT CAMSHAFT GEAR BACKLASH
a. Install camshaft timing gear assembly
b. Install the camshafts to the cylinder head.

NOTICE:
^ Install without valves and sub-gear.
^ Install with its timing mark matched.

c. Set the dial indicator to the teeth of the intake camshaft at a right angle (90°).

d. Measure the backlash of the camshaft timing gear at least 4 positions.
Standard backlash: 0.020 to 0.200 mm (0.0008 to 0.0079 inch)
Maximum backlash: 0.30 mm (0.0118 inch)
77. INSPECT CAMSHAFT THRUST CLEARANCE
a. Install the camshafts.

b. Using a dial indicator, measure the thrust clearance while moving the camshaft back and forth.
Standard thrust clearance: 0.040 to 0.090 mm (0.0016 to 0.0035 inch)
Maximum thrust clearance: 0.12 mm (0.0047 inch)
If the thrust clearance is greater than the maximum, replace the camshaft. If necessary, replace the bearing caps and cylinder head together.
78. INSPECT CAMSHAFT OIL CLEARANCE
a. Clean the bearing caps and camshaft journals.
b. Place the camshafts on the cylinder head.

c. Lay a strip of Plastigage across each of the camshaft journal.
d. Install the bearing caps.
Torque: 16 Nm (163 kgf-cm, 12 ft. lbs.)

NOTICE: Do not turn the camshaft.

e. Remove the bearing caps.

f. Measure the Plastigage at its widest point.
Standard oil clearance:
Intake #4, #5 journals: 0.025 to 0.057 mm (0.0010 to 0.0022 inch)
Other journals: 0.025 to 0.062 mm (0.0010 to 0.0024 inch)
Maximum oil clearance: 0.10 mm (0.0039 inch)
If the oil clearance is greater than the maximum, replace the camshaft. If necessary, replace the bearing caps and cylinder head together.

NOTICE: Completely remove the Plastigage.

79. REMOVE CYLINDER BLOCK WATER DRAIN COCK SUB-ASSEMBLY
a. Remove the water drain cock sub-assembly from the cylinder block.
80. REMOVE WATER SEAL PLATE
a. Remove the 2 nuts and water seal plate from the cylinder block.
81. REMOVE CYLINDER BLOCK W/HEAD STRAIGHT SCREW NO. 1 PLUG
a. Using a socket hexagon wrench 10 mm, remove the straight screw No. 1 plug and gasket.
82. REMOVE CYLINDER BLOCK W/HEAD STRAIGHT SCREW NO. 2 PLUG
a. Using a socket hexagon wrench 10 mm, remove the straight screw No. 2 plug and gasket.
83. REMOVE CYLINDER BLOCK W/HEAD STRAIGHT SCREW NO. 3 PLUG
a. Using a socket hexagon wrench 10 mm, remove the straight screw No. 3 plug and gasket.

84. INSPECT CONNECTING ROD THRUST CLEARANCE
a. Using a dial indicator, measure the thrust clearance while moving the connecting rod back and forth.
Standard thrust clearance: 0.15 to 0.30 mm (0.0059 to 0.0118 inch)
Maximum thrust clearance: 0.35 mm (0.0138 inch)
85. INSPECT CONNECTING ROD OIL CLEARANCE
a. Check that the matchmarks on the connecting rod and cap are aligned to ensure correct reassembly.
b. Remove the 2 connecting rod cap bolts.
c. Clean the crank pin, the bearing and the connecting rod.
d. Check the crank pin and bearing for pits and scratches.

e. Lay a strip of Plastigage across the crank pin.

f. Check that the protrusion of the connecting rod cap is facing the correct direction.
g. Apply a light coat of engine oil to the threads of the connecting rod cap bolts.

h. Tighten the bolts in several steps to the specified torque.
Torque: 25 Nm (255 kgf-cm, 18 ft. lbs.)

i. Mark the front side of each connecting cap bolt with paint.

j. Retighten the cap bolts by 90° as shown in the illustration.

NOTICE: Do not turn the crankshaft.

k. Remove the 2 bolts, the connecting rod cap and the lower bearing.

l. Measure the Plastigage at its widest point.
Standard oil clearance: 0.038 to 0.066 mm (0.0015 to 0.0026 inch)
Maximum oil clearance: 0.08 mm (0.0031 inch)

NOTICE: Completely remove the Plastigage.

m. If replacing the bearing, replace it with one having the same number as marked on the connecting rod.

HINT:
^ Standard bearing center wall thickness
^ There are 4 sizes of standard bearings, marked 1, 2, 3 and 4 accordingly

86. REMOVE PISTON SUB-ASSEMBLY W/CONNECTING ROD
a. Using a ridge reamer, remove all the carbon from the top of the cylinder.
b. Push out the piston and the connecting rod assembly from the top of the cylinder block.

HINT:
^ Keep the bearings, the connecting rod and the cap together.
^ Arrange the piston and the connecting rod assemblies in the correct order so they can be returned to the original locations when reassembling.

87. REMOVE CONNECTING ROD BEARING
a. Remove the connecting rod bearing from the connecting rod and connecting rod bearing cap.

88. REMOVE PISTON RING SET
a. Using a piston ring expander, remove the 2 compression rings.
b. Using a piston ring expander, remove the oil ring side rail.
c. Remove the oil ring expander by hand.

89. REMOVE PISTON PIN HOLE SNAP RING
a. Using a screwdriver, pry out the 2 snap rings.

90. REMOVE W/PIN PISTON SUB-ASSEMBLY
a. Gradually heat the piston to approximately 80°C (176°F).

b. Using a plastic hammer and a brass bar, lightly tap out the piston pin and remove the connecting rod.

HINT:
^ The piston and pin are a matched set.
^ Store the pistons, the pins, the rings, the connecting rods and the bearings in the correct order so that they can be returned to the original locations when reassembling.

91. INSPECT CRANKSHAFT THRUST CLEARANCE
a. Using a dial indicator, measure the thrust clearance while prying the crankshaft back and forth with a screwdriver.
Standard thrust clearance: 0.04 to 0.24 mm (0.0016 to 0.0094 inch)
Maximum thrust clearance: 0.30 mm (0.0118 inch)
If the thrust clearance is greater than the maximum, replace the thrust washers as a set. Check the crankshaft for wear, repair or replace if necessary.

HINT: Thrust washer thickness is 1.93 to 1.98 mm (0.0760 to 0.0780 inch)