Part 1

1GR-FE ENGINE MECHANICAL: ENGINE UNIT: INSPECTION

INSPECTION

1. INSPECT CAMSHAFTS

(a) Inspect the camshaft for runout.
(1) Place the camshaft on V-blocks.
(2) Using a dial indicator, measure the runout at the center journal.
Maximum runout:
0.06 mm (0.0024 in.)
If the runout is greater than the maximum, replace the camshaft.

(b) Inspect the cam lobes.
(1) Using a micrometer, measure the cam lobe height.
Standard cam lobe height:
Intake
44.168 to 44.268 mm (1.7389 to 1.7428 in.)
Exhaust
44.580 to 44.680 mm (1.7551 to 1.7591 in.)
Minimum cam lobe height:
Intake
44.018 mm (1.7330 in.)
Exhaust
44.430 mm (1.7492 in.)
If the cam lobe height is less than the minimum, replace the camshaft.

(c) Inspect the camshaft journals.
(1) Using a micrometer, measure the journal diameter.
No. 1 journal diameter:
35.971 to 35.985 mm (1.4162 to 1.4167 in.)
Other journal diameter:
22.959 to 22.975 mm (0.9039 to 0.9045 in.)
If the journal diameter is not as specified, check the oil clearance.
2. INSPECT CAMSHAFT TIMING GEAR ASSEMBLY
(a) Fix the intake camshaft with a vise.

NOTE: Be careful not to damage the camshaft.

(b) Align the knock pin hole in the camshaft timing gear assembly with the knock pin of the camshaft, and install the camshaft timing gear assembly with the bolt.
Torque: 100 Nm (1,020 kgf-cm, 74 ft-lbf)
(c) Confirm the camshaft timing gear assembly is locked.
(d) Release the lock pin.

(1) Cover 4 oil paths of the cam journal with a masking tape as shown in the illustration.

HINT: One of the 2 grooves on the cam journal is for retards (upper) and the other is for advances (lower). Each groove has 2 oil paths. Plug one of the oil paths for each groove with rubber pieces before wrapping the cam journal with tape.

(2) Prick a hole in the tape placed on the advance side path. Prick a hole in the retard side path, on the opposite side to that of the advance side path, as shown in the illustration.

(3) Apply about 200 kPa (2.0 kgf/cm2) of air pressure to the two broken paths (the advance side path and the retard side path).

NOTE: Cover the paths with a shop rag to avoid oil splashing.

(4) Confirm that the camshaft timing gear assembly rotates in the advance direction when reducing the air pressure applied to the retard path.

HINT: When the lock pin is released, the camshaft timing gear rotates in the advance direction.

(5) When the camshaft timing gear comes to the most advanced position, release the air pressure from the retard side path, and then release the air pressure from the advance side path.

NOTE: The camshaft timing assembly gear occasionally shifts to the retard side abruptly, if air compression of the advanced side path is released first. It often results in the breakage of the lock pin.

(e) Check for smooth revolution.
(1) Except the position where the lock pin meets at the most retard angle, turn the camshaft timing gear assembly back and forth and check the movable range and that there is no disturbance.
Standard:
Movable smoothly in the range about 31°

NOTE: Be sure to perform this check by hand, instead of air pressure.

(f) Check the lock in the most retarded position.
(1) Confirm that the camshaft timing gear assembly is locked at the most retarded position.

(g) Remove the set bolt and camshaft timing gear assembly.

NOTE: Be sure not to remove the other 3 bolts.

3. INSPECT CYLINDER HEAD SET BOLT

(a) Using vernier calipers, measure the outside thread diameter of the bolt.
Standard outside diameter:
10.85 to 11.00 mm (0.4272 to 0.4331 in.)
Minimum outside diameter:
10.7 mm (0.421 in.)
4. INSPECT CHAIN SUB-ASSEMBLY

(a) Using a spring scale, pull the chain sub assembly with a force of 147 N (15.0 kgf, 33.1 lbf) and measure the length of the chain sub assembly by vernier calipers.
Maximum chain elongation:
146.8 mm (5.780 in.)

NOTE:
Perform the same measurements by pulling at random in 3 or more places to obtain an average length.
If the elongation is greater than the maximum, replace the chain.

5. INSPECT NO. 2 CHAIN SUB-ASSEMBLY

(a) Put the No. 1 chain on the larger gear of the camshaft timing gear assembly.
(b) Using vernier calipers, measure the timing gear with the chain.
Minimum gear diameter (with chain):
115.5 mm (4.547 in.)

NOTE:
The vernier calipers must contact the chain rollers for the measuring.
If the diameter is less than the minimum, replace the No. 1 chain and camshaft timing gear assembly.

(c) Put the No. 2 chain on the smaller gear of the camshaft timing gear assembly.
(d) Using vernier calipers, measure the timing gear with the chain.
Minimum gear diameter (with chain):
73.1 mm (2.878 in.)

NOTE:
The vernier calipers must contact the chain rollers for the measuring.
If the diameter is less than the minimum, replace the No. 2 chain and camshaft timing gear assembly.

7. INSPECT CAMSHAFT TIMING GEAR OR SPROCKET

(a) Put the No. 2 chain on the camshaft timing gear.
(b) Using vernier calipers, measure the camshaft timing gear diameter with the chain.
Minimum gear diameter (with chain):
73.1 mm (2.878 in.)

NOTE:
The vernier calipers must contact the chain rollers for the measuring.
If the diameter is less than the minimum, replace the No. 2 chain and the camshaft timing gear.

8. INSPECT CRANKSHAFT TIMING GEAR OR SPROCKET

(a) Put the No. 1 chain on the crankshaft timing gear.
(b) Using vernier calipers, measure the crankshaft timing gear diameter with the chain.
Minimum gear diameter (with chain):
61.0 mm (2.402 in.)

NOTE:
The vernier calipers must contact the chain rollers for the measuring.
If the diameter is less than the minimum, replace the No. 1 chain and crankshaft timing gear.

9. INSPECT NO. 1 IDLE GEAR

(a) Put the No. 1 chain on the idle gear.
(b) Using vernier calipers, measure the idle gear with the chain.
Minimum gear diameter (with chain):
61.0 mm (2.402 in.)

NOTE:
The vernier calipers must contact the chain rollers for the measuring.
If the diameter is less than the minimum, replace the No. 1 chain and idle gear.

10. INSPECT IDLE GEAR SHAFT OIL CLEARANCE

(a) Using a micrometer, measure the idle gear shaft diameter.
Idle gear shaft diameter:
22.987 to 23.000 mm (0.9050 to 0.9055 in.)

(b) Using a caliper gauge, measure the inside diameter of the idle gear.
Idle gear inside diameter:
23.02 to 23.03 mm (0.9063 to 0.9067 in.)
(c) Subtract the idle gear shaft diameter measurement from the idle gear inside diameter measurement.
Standard oil clearance:
0.020 to 0.043 mm (0.0008 to 0.0017 in.)
Maximum oil clearance:
0.093 mm (0.0037 in.)
11. INSPECT NO. 1 CHAIN TENSIONER ASSEMBLY

(a) Check that the plunger moves smoothly when the ratchet pawl is raised with your finger.
(b) Release the ratchet pawl and check that the plunger is locked in place by the ratchet pawl and does not move when pushing with your finger.
12. INSPECT NO. 2 CHAIN TENSIONER ASSEMBLY

(a) Check that the plunger moves smoothly.
(b) Measure the worn depth of the chain tensioner slipper.
Maximum depth:
1.0 mm (0.039 in.)
If the depth is greater than the maximum, replace the No. 2 chain tensioner.
13. INSPECT NO. 3 CHAIN TENSIONER ASSEMBLY

(a) Check that the plunger moves smoothly.
(b) Measure the worn depth of the chain tensioner slipper.
Maximum depth:
1.0 mm (0.039 in.)
If the depth is greater than the maximum, replace the No. 3 chain tensioner.
14. INSPECT CHAIN TENSIONER SLIPPER

(a) Measure the worn depth of the chain tensioner slipper.
Maximum depth:
1.0 mm (0.039 in.)
If the depth is greater than the maximum, replace the chain tensioner slipper.
15. INSPECT NO. 1 CHAIN VIBRATION DAMPER

(a) Measure the worn depth of the No. 1 chain vibration damper.
Maximum depth:
1.0 mm (0.039 in.)
If the depth is greater than the maximum, replace the No. 1 chain vibration damper.
16. INSPECT NO. 2 CHAIN VIBRATION DAMPER

(a) Measure the worn depth of the No. 2 chain vibration damper.
Maximum depth:
1.0 mm (0.039 in.)
If the depth is greater than the maximum, replace the No. 2 chain vibration damper.
17. CLEAN CYLINDER HEAD SUB-ASSEMBLY

(a) Using a gasket scraper, remove all the gasket material from the cylinder block contact surface.

NOTE: Be careful not to scratch the cylinder block contact surface.

(b) Using a wire brush, remove all the carbon from the combustion chambers.

NOTE: Be careful not to scratch the combustion chambers.

(d) Using a soft brush and solvent, thoroughly clean the cylinder head.
18. INSPECT CYLINDER HEAD SUB-ASSEMBLY

(a) Inspect warpage.
(1) Using a precision straight edge and feeler gauge, measure the warpage of the contact surfaces of the cylinder block and manifolds.
Maximum warpage:
0.10 mm (0.0039 in.)
If warpage is greater than the maximum, replace the cylinder head.

(b) Inspect cranks.
(1) Using a dye penetrant, check the combustion chamber, intake ports, exhaust ports and cylinder block surface for cracks.
If cracked, replace the cylinder head.
19. CLEAN VALVE

(a) Using a gasket scraper, chip off any carbon from the valve head.
(b) Using a wire brush, thoroughly clean the valve.
20. INSPECT VALVE

(a) Inspect the valve stem diameter.
(1) Using a micrometer, measure the diameter of the valve stem.
Valve stem diameter:

(b) Inspect the valve face angle.
(1) Grind the valve enough to remove pits and carbon.
(2) Check that the valve is ground to the correct valve face angle.
Valve face angle:
44.5°

(c) Inspect the valve head margin thickness.
(1) Using vernier calipers, check the valve head margin thickness.
Standard margin thickness:
1.0 mm (0.039 in.)
Minimum margin thickness:
0.5 mm (0.020 in.)
If the margin thickness is less than the minimum, replace the valve.

(d) Inspect the overall length.
(1) Using vernier calipers, check the overall length.
Standard overall length:

Minimum overall length:

If the overall length is less than the minimum, replace the valve.

(e) Inspect the valve stem tip.
(1) Check the surface of the valve stem tip for wear.

NOTE: Do not grind off more than the minimum length.

If the valve stem tip is worn, resurface the tip with a grinder or replace the valve.
21. CLEAN VALVE SEAT

(a) Using a 45° carbide cutter, resurface the valve seats.
(b) Clean the valve seats.
22. INSPECT VALVE SEAT

(a) Apply a light coat of prussian blue (or white lead) to the valve face.
(b) Lightly press the valve against the valve seat.

NOTE: Do not rotate the valve.

(c) Check the valve face and seat according to the following procedure.
(1) If prussian blue appears around the entire face, the valve is centered.
If not, replace the valve.
(2) If prussian blue appears around the entire valve seat, the guide and face are centered.
If not, resurface the valve seat.
(3) Check that the seat contacts the middle of the valve face with the width below.
Standard width:
1.0 to 1.4 mm (0.039 to 0.055 in.)
23. REPAIR VALVE SEAT

NOTE: Take off a cutter gradually to make the intake valve seat smooth.

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

(b) Intake side:
If the seating is too low to the valve face, use 60° and 45° cutters to correct the seat.

(d) Handrub the valve and valve seat with an abrasive compound.
(e) After handrubbing, clean the valve and valve seat.