Engine Unit - Inspection

1. Inspect timing belt

2. Inspect no. 1 chain tensioner assembly

3. Inspect timing belt idler

4. Inspect cylinder head set bolt

5. Inspect camshafts

6. Inspect camshaft timing tube assembly

7. Inspect camshaft gear spring

8. Inspect cylinder head sub-assembly

9. Inspect valve

10. Inspect valve spring

11. Inspect valve guide bush

12. Remove valve guide bush

13. Install valve guide bush

14. Inspect valve seat

15. Repair valve seat

16. Inspect valve lifter

17. Inspect camshaft oil clearance

18. Inspect camshaft thrust clearance

19. Inspect camshaft gear backlash

20. Clean cylinder block sub-assembly

21. Inspect cylinder block sub-assembly

22. Inspect piston

23. Inspect piston ring set

24. Inspect connecting rod sub-assembly

25. Remove connecting rod small end bush

26. Install connecting rod small end bush

27. Inspect connecting rod bolt

28. Inspect crankshaft bearing cap bolt

29. Inspect crankshaft

​

HINT:

1. Thoroughly clean all parts to be assembled.
   
2. Before installing the parts, apply new engine oil to all sliding and rotating surfaces.
   
3. Replace all gaskets, O-rings and oil seals with new ones.
   

NOTICE:

1. Do not bend, twist or turn the timing belt inside out.
   
2. Do not allow the timing belt to come into contact with oil, water or steam.
   
3. Do not utilize timing belt tension when installing or removing the mount bolt of the camshaft timing pulley.
   

1. If premature parting occurs, check the following:

   1. Check for proper installation.
      
   2. Check the timing cover gasket for damage and proper installation.
      

2. If the belt teeth are cracked or damaged, inspect the camshaft.

3. If there is noticeable wear or cracks on the belt face, check if there are nicks on the side of the idler pulley lock and water pump.

4. If there is wear or damage on only one side of the belt, check the belt guide and alignment of each pulley.

5. If there is noticeable wear on the belt teeth, check for damage on the timing belt or foreign objects on the pulley teeth. Check if the gasket is installed correctly.
   If necessary, replace the timing belt.

1. Visually check the seal portion of the tensioner for oil leakage.

   HINT:

   If there is a faint trace of oil on the seal on the push rod side, the tensioner is all right.

   If leakage is found, replace the tensioner.

2. Hold the tensioner by hands and push the push rod strongly as shown in the illustration to check that it does not move.
   If the push rod moves, replace the tensioner.

   NOTICE:

   Do not face the tensioner push rod downward.

3. Measure the protrusion of the push rod from the housing end.

   Protrusion:

   11.2 to 12.2 mm (0.440 to 0.480 in.)
   

   If the protrusion is not as specified, replace the tensioner.
   

1. Visually check the seal portion of the idler pulley for oil leakage.
   If leakage is found, replace the idler pulley.

2. Check that the idler pulley turns smoothly.
   If necessary, replace the idler.

1. Using vernier calipers, measure the thread outside diameter of the bolt.

   Standard outside diameter:

   9.810 to 9.960 mm (0.3862 to 0.3921 in.)
   

   Minimum outside diameter:

   9.700 mm (0.3819 in.)
   

1. Inspect the camshaft for runout.
   

   1. Place the camshaft on V-blocks.

   2. Using a dial indicator, measure the circle runout at the center journal.

      Maximum circle runout:

      0.08 mm (0.0031 in.)
      

      If the circle runout is greater than maximum, replace the camshaft.
      

2. Inspect the cam lobes.
   

   1. Using a micrometer, measure the cam lobe height.

      Standard cam lobe height:

      Intake:

      41.94 to 42.04 mm (1.6512 to 1.6551 in.)
      

      Exhaust:

      41.96 to 42.06 mm (1.6520 to 1.6559 in.)
      

      Minimum cam lobe height:

      Intake:

      41.79 mm (1.6453 in.)
      

      Exhaust:

      41.81 mm (1.6461 in.)
      

      If the cam lobe height is less than the minimum, replace the camshaft.
      

3. Inspect the camshaft journals.
   

   1. Using a micrometer, measure the journal diameter.

      Journal diameter:

      26.954 to 26.970 mm (1.0612 to 1.0618 in.)
      

      If the journal diameter is not as specified, check the oil clearance.
      

1. Using a micrometer, measure the journal diameter.

   Journal diameter:

   39.955 to 39.964 mm (1.5730 to 1.5734 in.)
   

   If the journal diameter is not as specified, check the oil clearance.
   

2. Install the timing tube to the intake camshaft, and check that the timing tube turns smoothly.
   If necessary, replace the timing tube and intake camshaft.

1. Using vernier calipers, measure the gap distance of the gear spring.

   Gap distance:

   18.2 to 18.8 mm (0.717 to 0.740 in.)
   

   If the gap distance is not as specified, replace the gear spring.
   

1. Clean the cylinder head.
   

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

      NOTICE:

      Be careful not to scratch the cylinder block contact surface.

   3. Using a wire brush, remove all the carbon from the combustion chambers.

      NOTICE:

      Be careful not to scratch the cylinder block contact surface.

   5. Using a valve guide bushing brush and solvent, clean all the guide bushes.

   7. Using a soft brush and solvent, thoroughly clean the cylinder head.

2. Inspect for warpage.
   

   1. Using a precision straight edge and feeler gauge, measure the warpage of the contact surfaces of the cylinder block and the manifolds.

      Maximum warpage:

      0.10 mm (0.0039 in.)
      

      If warpage is greater than the maximum, replace the cylinder head.
      

3. Inspect for cracks.
   

   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.

1. Clean the valves.
   

   1. Using a gasket scraper, chip off any carbon from the valve head.

   2. Using a wire brush, thoroughly clean the valve.

2. Using a micrometer, measure the diameter of the valve stem.

   Valve stem diameter:

   Intake:

   5.470 to 5.485 mm (0.2154 to 0.2159 in.)
   

   Exhaust:

   5.465 to 5.480 mm (0.2152 to 0.2157 in.)
   

3. Check 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°
      

4. Check the valve head margin thickness.

   Standard margin thickness:

   Intake:

   1.25 mm (0.049 in.)
   

   Exhaust:

   1.4 mm (0.055 in.)
   

   Minimum margin thickness:

   0.5 mm (0.020 in.)
   

   If the margin thickness is less than the minimum, replace the valve.
   

5. Check the valve overall length.

   Standard overall length:

   Intake:

   95.05 mm (3.7421 in.)
   

   Exhaust:

   95.10 mm (3.7441 in.)
   

   Minimum overall length:

   Intake:

   94.55 mm (3.7224 in.)
   

   Exhaust:

   94.60 mm (3.7244 in.)
   

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

6. Check the surface of the valve stem tip for wear.
   If the valve stem tip is worn, resurface the tip with a grinder or replace the valve.

   NOTICE:

   Do not grind off more than the minimum.

1. Using a steel square, measure the deviation of the valve spring.

   Maximum deviation:

   2.0 mm (0.079 in.)
   

   If the deviation is greater than the maximum, replace the valve spring.
   

2. Using vernier calipers, measure the free length of the valve spring.

   Free length:

   54.1 mm (2.130 in.)
   

   If the free length is not as specified, replace the valve spring.
   

3. Using a spring tester, measure the tension of the valve spring at the specified installed length.

   Installed tension:

   210 to 226 N (21.4 to 23.0 kgf, 47.2 to 50.7 lbf) at 35.0 mm (1.378 in.)
   

   If the installed tension is not as specified, replace the valve spring.
   

1. Using a caliper gauge, measure the inside diameter of the guide bush.

   Bush inside diameter:

   5.510 to 5.530 mm (0.2169 to 0.2177 in.)
   

2. Subtract the valve stem diameter measurement from the guide bush inside diameter measurement.

   Standard oil clearance:

   Intake:

   0.025 to 0.060 mm (0.0010 to 0.0024 in.)
   

   Exhaust:

   0.030 to 0.065 mm (0.0012 to 0.0026 in.)
   

   Maximum oil clearance:

   Intake:

   0.08 mm (0.0031 in.)
   

   Exhaust:

   0.10 mm (0.0039 in.)
   

   If the clearance is greater than the maximum, replace the valve and guide bush.
   

1. Gradually heat the cylinder head to 80 to 100°C (176 to 212°F).

2. Using SST and a hammer, tap out the guide bush.

   SST

   09201-10000 (09201-01060)
   09950-70010 (09951-07100)
   

1. Using a caliper gauge, measure the bush bore diameter of the cylinder head.

2. Select a new guide bush (STD or O/S 0.05).

   Bush bore diameter	Bush size
   10.285 to 10.306 mm (0.4049 to 0.4057 in.)	Use STD
   10.335 to 10.356 mm (0.4069 to 0.4077 in.)	Use O/S 0.05

   If the bush bore diameter of the cylinder head is greater than 10.306 mm (0.4057 in.), machine the bush bore so that the dimension is between 10.335 and 10.356 mm (0.4069 and 0.4077 in.).
   If the bush bore diameter of the cylinder head is greater than 10.356 mm (0.4077 in.), replace the cylinder head.
   

   HINT:

   Different bushes are used for the intake and exhaust.

3. Gradually heat the cylinder head to 80 to 100°C (176 to 212°F).

4. Using SST and a hammer, tap in a new guide bush to the specified protrusion height.

   Protrusion height:

   Intake:

   9.2 to 9.8 mm (0.362 to 0.386 in.)
   

   Exhaust:

   8.2 to 8.8 mm (0.323 to 0.346 in.)
   

   SST

   09201-01055
   09950-70010 (09951-07100)
   

5. Using a sharp 5.5mm reamer, ream the guide bush to obtain the specified clearance between the guide bush and valve stem.

   SST

   09201-10000 (09201-01060)
   09950-70010 (09951-07100)
   

1. Using a 45° carbide cutter, resurface the valve seats. Clean metal filings from the valve seats.

2. Check the valve seating position.
   

   1. Apply a light coat of prussian blue (or white lead) to the valve face.

   2. Lightly press the valve against the seat. Do not rotate valve.

3. Check the valve face and seat for the following:
   

   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 seat.

   3. Check that the seat contacts in the middle of the valve face with the following width:

      Width:

      1.0 to 1.4 mm (0.039 to 0.055 in.)
      

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

2. If the seating is too low on the valve face, use 60° and 45° cutters to correct the seat.

3. Handrub the valve and valve seat with an abrasive compound.

4. After handrubbing, clean the valve and valve seat.

1. Using a caliper gauge, measure the lifter bore diameter of the cylinder head.

   Lifter bore diameter:

   31.000 to 31.016 mm (1.2205 to 1.2211 in.)
   

2. Using a micrometer, measure the lifter diameter where the distance from the top surface is 12.3 to 12.7 mm (0.484 to 0.500 in.).

   Lifter diameter:

   30.968 to 30.976 mm (1.2192 to 1.2195 in.)
   

3. Subtract the lifter diameter measurement from the lifter bore diameter measurement.

   Standard oil clearance:

   0.024 to 0.050 mm (0.0009 to 0.0020 in.)
   

   Maximum oil clearance:

   0.07 mm (0.0028 in.)
   

   If the oil clearance is greater than the maximum, replace the lifter. If necessary, replace the cylinder head.
   

1. Install the camshaft timing tube to the camshaft (Click here).

2. Clean the bearing caps and camshaft journals.

3. Check the bearings for flaking and scoring.
   If the bearings are damaged, replace the bearing caps and cylinder head as a set.

4. Place the camshafts on the cylinder head.

5. Lay a strip of Plastigage across each of the camshaft journals.

6. Install the bearing caps (Click here).

   Torque:

   For bolt A:

   7.5 N*m{76 kgf*cm, 66 ft.*lbf}

   For others:

   16 N*m{163 kgf*cm, 12 ft.*lbf}

   NOTICE:

   Do not turn the camshaft.

7. Remove the bearing caps.

8. Measure the Plastigage at its widest point.

   Standard oil clearance:

   Camshaft journal	Camshaft timing tube journal
   0.030 to 0.071 mm (0.0012 to 0.0028 in.)	0.036 to 0.057 mm (0.0014 to 0.0022 in.)

   Maximum oil clearance:

   Camshaft journal	Camshaft timing tube journal
   0.100 mm (0.0039 in.)	0.075 mm (0.0030 in.)

   If the oil clearance is greater than the maximum, replace the camshaft. If necessary, replace the bearing caps and cylinder head as a set.
   

9. Remove the camshafts.

10. Completely remove the Plastigage.

1. Install the camshaft (Click here).

2. Using a dial indicator, measure the thrust clearance while moving the camshaft back and forth.

   Standard thrust clearance:

   Intake	Exhaust
   0 to 0.040 mm (0 to 0.0016 in.)	0.030 to 0.070 mm (0.0012 to 0.0028 in.)

   Maximum thrust clearance:

   Intake	Exhaust
   0.12 mm (0.0047 in.)	0.10 mm (0.0039 in.)

   If the thrust clearance is greater than the maximum, replace the camshaft. If necessary, replace the bearing caps and cylinder head as a set.
   

3. Remove the camshafts.

4. Remove the camshaft timing tube from the intake camshaft.

1. Install the drive gear to the camshaft timing tube (Click here).

2. Install the camshaft timing tube to the intake camshaft (Click here).

3. Install the camshafts without installing the exhaust camshaft sub-gear No. 3 and front bearing cap (Click here).

4. Using a dial indicator, measure the backlash.

   Standard backlash:

   0.020 to 0.200 mm (0.0008 to 0.0079 in.)
   

   Maximum backlash:

   0.30 mm (0.0118 in.)
   

   If the backlash is greater than the maximum, replace the intake camshaft drive gear and exhaust camshaft.
   

5. Remove the camshafts.

6. Remove the camshaft timing tube from the intake camshaft.

7. Remove the drive gear from the camshaft timing tube.

1. Using a gasket scraper, remove all the gasket material from the top surface of the cylinder block.

2. Using a soft brush and solvent, thoroughly clean the cylinder block.

1. Inspect for warpage.
   

   1. Using a precision straight edge and feeler gauge, measure the warpage of the contact surfaces of the cylinder head and crankshaft bearing cap.

      Maximum warpage:

      0.07 mm (0.0028 in.)
      

      If warpage is greater than the maximum, replace the cylinder block sub-assembly.
      

2. Visually check the cylinder for vertical scratches.
   If deep scratches are present, rebore all the 8 cylinders and replace all the 8 pistons. If necessary, replace the cylinder block.

3. Inspect the cylinder bore diameter.

   HINT:

   There are 3 sizes of the standard cylinder bore diameter, marked "1", "2" and "3" accordingly. The mark is stamped on the top of the cylinder block.

   
   
   2. Using a cylinder gauge, measure the cylinder bore diameter at positions A and B in the thrust and axial directions.

      Standard diameter:

      STD
      Mark "1"	Mark "2"	Mark "3"
      94.002 to 94.010 mm (3.7009 to 3.7012 in.)	94.010 to 94.023 mm (3.7012 to 3.7017 in.)	94.023 to 94.031 mm (3.7017 to 3.7020 in.)

      Maximum diameter:

      94.230 mm (3.5917 in.)
      

      If the diameter is greater than the maximum, rebore all the 8 cylinders and replace all the 8 pistons. If necessary, replace the cylinder block.
      

      STD	94.231 mm (3.7099 in.)
      O/S 0.50	94.731 mm (3.7296 in.)

4. Remove the cylinder ridge.
   If the wear is less than 0.2mm (0.008 in.), using a ridge reamer, grind the top of the cylinder.

1. Clean the piston.
   

   1. Using a gasket scraper, remove the carbon from the piston top.

   3. Using a groove cleaning tool or broken ring, clean the piston ring grooves.

   5. Using solvent and a brush, thoroughly clean the piston.

      NOTICE:

      Do not use a wire brush.

2. Inspect the piston oil clearance.

   HINT:

   There are 3 sizes of the standard piston diameter, marked "1", "2" or "3" accordingly. The mark is stamped on the piston top.

   
   

   1. Using a micrometer, measure the piston diameter at right angles to the piston pin center line, 30.75 mm (1.2106 in.) from the piston head.

      Piston diameter:

      O/S 0.50	STD
      	Mark "1"	Mark "2"	Mark "3"
      94.402 to 94.430 mm (3.7168 to 3.7177 in.)	93.902 to 93.912 mm (3.6969 to 3.6973 in.)	93.912 to 93.920 mm (3.6973 to 3.6976 in.)	93.920 to 93.930 mm (3.6976 to 3.6980 in.)

   3. Measure the cylinder bore diameter in the thrust directions.

   4. Subtract the piston diameter measurement from the cylinder bore diameter measurement.

      Standard oil clearance:

      0.090 to 0.111 mm (0.0035 to 0.0044 in.)
      

      Maximum oil clearance:

      0.13 mm (0.0051 in.)
      

      If the oil clearance is greater than the maximum, replace all the 8 pistons and rebore all the 8 cylinders. If necessary, replace the cylinder block.
      

      HINT:

      Use a new cylinder block:

      1. Use a piston with the same number mark as the cylinder diameter marked on the cylinder block.
         
      2. The shape of the piston varies for the LH and RH banks. The LH piston is marked with 1 cavity and "2", the RH piston with 2 cavities and "2".
         

3. Inspect the piston pin fit.
   

   1. Heat the piston to approx. 60° C (140° F), and push the piston pin into the piston pin hole with your thumb.

4. Using a micrometer, measure the piston pin diameter.

   Piston pin diameter:

   21.997 to 22.006 mm (0.8660 to 0.8664 in.)
   

1. Inspect the piston ring groove clearance.
   

   1. Using a feeler gauge, measure the clearance between the new piston ring and the wall of the ring groove.

      Ring groove clearance:

      No. 1	No. 2
      0.030 to 0.080 mm (0.0012 to 0.0032 in.)	0.020 to 0.060 mm (0.0008 to 0.0024 in.)

      If the clearance is not as specified, replace the piston.
      

2. Inspect the piston ring end gap.
   

   1. Insert the piston ring into the cylinder bore.

   2. Using a piston, push the piston ring a little beyond the bottom of the ring travel, 105 mm (4.13 in.) from the top of the cylinder block.

   4. Using a feeler gauge, measure the end gap.

      Standard end gap:

      No. 1	No. 2	Oil (Side rail)
      0.300 to 0.400 mm (0.0118 to 0.0158 in.)	0.400 to 0.550 mm (0.0158 to 0.0217 in.)	0.130 to 0.380 mm (0.0051 to 0.0150 in.)

      Maximum end gap:

      No. 1	No. 2	Oil (Side rail)
      1.10 mm (0.0433 in.)	1.30 mm (0.0512 in.)	0.90 mm (0.0354 in.)

      If the end gap is greater than the maximum, replace the piston ring. If the end gap is greater than the maximum, even with a new piston ring, rebore all the 8 cylinders or replace the cylinder block sub-assembly.
      

1. Using a rod aligner and feeler gauge, check the connecting rod alignment.
   

   1. Check for bend.

      Maximum bend:

      0.05 mm (0.0020 in.) per 100 mm (3.94 in.)
      

      If bend is greater than the maximum, replace the connecting rod sub-assembly.
      

   3. Check for twist.

      Maximum twist:

      0.15 mm (0.0059 in.) per 100 mm (3.94 in.)
      

      If twist is greater than the maximum, replace the connecting rod sub-assembly.
      

2. Inspect the piston pin oil clearance.
   

   1. Using a caliper gauge, measure the inside diameter of the connecting rod bushing.

      Bushing inside diameter:

      22.005 to 22.014 mm (0.8663 to 0.8667 in.)
      

   3. Using a micrometer, measure the piston pin diameter.

      Piston pin diameter:

      21.997 to 22.006 mm (0.8660 to 0.8664 in.)
      

   4. Subtract the piston pin diameter measurement from the bushing inside diameter measurement.

      Standard oil clearance:

      0.005 to 0.011 mm (0.0002 to 0.0004 in.)
      

      Maximum oil clearance:

      0.05 mm (0.0020 in.)
      

      If the oil clearance is greater than the maximum, replace the connecting rod sub-assembly. If necessary, replace the piston and piston pin as a set.
      

1. Using SST and a press, press out the bushing.

   SST

   09222-30010
   

1. Align the oil holes of a new bushing and the connecting rod.

2. Using SST and a press, press in the bushing.

   SST

   09222-30010
   

3. Using a pin hole grinder, hone the bushing to obtain the specified clearance between the bushing and piston pin.

4. Check the piston pin fit at normal room temperature. Coat the piston pin with engine oil, and push it into the connecting rod with your thumb.

1. Using vernier calipers, measure the tension portion diameter of the connecting rod bolt.

   Standard diameter:

   7.200 to 7.300 mm (0.2835 to 0.2874 in.)
   

   Minimum diameter:

   7.00 mm (0.2756 in.)
   

   If the diameter is less than the minimum, replace the bolt.
   

1. Using vernier calipers, measure the thread outside diameter of the crankshaft bearing cap bolt.

   Standard diameter:

   10.760 to 10.970 mm (0.4236 to 0.4319 in.)
   

   Minimum diameter:

   10.40 mm (0.4094 in.)
   

   If the diameter is less than the minimum, replace the cap bolt.
   

1. Inspect for circle runout.
   

   1. Place the crankshaft on V-blocks.

   2. Using a dial indicator, measure the circle runout at the center journal.

      Maximum circle runout:

      0.04 mm (0.0016 in.)
      

      If the circle runout is greater than the maximum, replace the crankshaft.
      

2. Inspect the crankshaft journals and crank pins.
   

   1. Using a micrometer, measure the diameter of each crankshaft journal and crank pin.

      Crankshaft journal diameter:

      66.988 to 67.000 mm (2.6373 to 2.6378 in.)
      

      Crank pin diameter:

      51.982 to 52.000 mm (2.0465 to 2.0472 in.)
      

      If the diameter is not as specified, check the oil clearance. If necessary, replace the crankshaft.
      

   2. Check each crankshaft journal and crank pin for taper and out-of-round as shown in the illustration.

      Maximum taper and out-of-round:

      0.02 mm (0.0008 in.)
      

      If the taper and out-of-round is greater than the maximum, replace the crankshaft.