Engine Unit Inspection

Inspect the circle 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.)
   

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

Using a micrometer, measure the cam lobe height.

Standard cam lobe height:

42.610 to 42.710 mm (1.6776 to 1.6815 in.)

Minimum cam lobe height:

42.46 mm (1.6717 in.)

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

Inspect the journal diameter of the camshaft.

1. Using a micrometer, measure the journal diameter of the camshaft for the camshaft bearing.
   

   Journal diameter:

   26.954 to 26.970 mm (1.0612 to 1.0618 in.)
   

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




2. Using a micrometer, measure the journal diameter for the camshaft timing tube.
   

   Journal diameter:

   30.984 to 31.000 mm (1.2198 to 1.2205 in.)
   

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

Inspect the journal diameter of the camshaft timing tube.

1. Using a micrometer, measure the journal diameter.
   

   Journal diameter:

   39.955 to 39.964 mm (1.5730 to 1.5734 in.)
   

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

Install the camshaft timing tube to the camshaft, and check that the timing tube turns smoothly.

1. If necessary, replace the timing tube and camshaft.
   

Check the oil clearance.

1. Install the camshaft timing tube to the camshaft.
   

2. Clean the bearing caps and journals.
   

3. Check the bearings for flaking and scoring.
   

   1. If the bearings are damaged, replace the bearing caps and cylinder head as a set.
      

4. Place the camshaft on the cylinder head.
   

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

6. Install the bearing caps.
   

   NOTICE:

   Do not turn the camshaft.

7. Remove the bearing caps.
   





8. Measure the Plastigage at its widest point.
   

   Standard oil clearance:

   Journal	Oil clearance
   Camshaft journal	0.030 to 0.067 mm (0.0012 to 0.0026 in.)
   Camshaft timing tube journal	0.036 to 0.057 mm (0.0014 to 0.0022 in.)

   Maximum oil clearance:

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

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

9. Completely remove the Plastigage.
   

10. Remove the camshaft.
    

11. Remove the camshaft timing tube from the camshaft.
    

Check the thrust clearance.

1. Install the camshaft timing tube to the camshaft.
   

2. Install the camshaft.
   

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

   Standard thrust clearance:

   0.060 to 0.100 mm (0.0024 to 0.0039 in.)
   

   Maximum thrust clearance:

   0.13 mm (0.0051 in.)
   

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

4. Remove the camshaft.
   

5. Remove the camshaft timing tube from the camshaft.
   

Check the gear backlash.

1. Install the drive gear to the camshaft timing tube.
   

2. Install the camshaft timing tube to the camshaft.
   

3. Install the camshaft and No. 2 camshaft without installing the camshaft sub-gear and front bearing cap.
   

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.)
   

   1. If the backlash is greater than the maximum, replace the drive gear and No. 2 camshaft.
      

Remove the camshaft and No. 2 camshaft.

Remove the camshaft timing tube from the camshaft.

Remove the drive gear from the camshaft timing tube.

Inspect the circle 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.)
   

   1. If the circle runout is greater than the maximum, replace the No. 3 camshaft.
      

Using a micrometer, measure the cam lobe height.

Standard cam lobe height:

42.610 to 42.710 mm (1.6776 to 1.6815 in.)

Minimum cam lobe height:

42.46 mm (1.6717 in.)

1. If the cam lobe height is less than the minimum, replace the No. 3 camshaft.
   

Inspect the journal diameter of the camshaft.

1. Using a micrometer, measure the journal diameter of the No. 3 camshaft for the camshaft bearing.
   

   Journal diameter:

   26.954 to 26.970 mm (1.0612 to 1.0618 in.)
   

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




2. Using a micrometer, measure the journal diameter for the camshaft timing tube.
   

   Journal diameter:

   30.984 to 31.000 mm (1.2198 to 1.2205 in.)
   

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

Inspect the journal diameter of the camshaft timing tube.

1. Using a micrometer, measure the journal diameter.
   

   Journal diameter:

   39.955 to 39.964 mm (1.5730 to 1.5734 in.)
   

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

Install the timing tube to the No. 3 camshaft, and check the timing tube turns smoothly.

1. If necessary, replace the timing tube and No. 3 camshaft.
   

Check the oil clearance.

1. Install the camshaft timing tube to the No. 3 camshaft.
   

2. Clean the bearing caps and journals.
   

3. Check the bearings for flaking and scoring.
   

   1. If the bearings are damaged, replace the bearing caps and cylinder head as a set.
      

4. Place the No. 3 camshaft on the cylinder head.
   

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

6. Install the bearing caps.
   

   NOTICE:

   Be careful not to turn the camshaft.

7. Remove the bearing caps.
   





8. Measure the Plastigage at its widest point.
   

   Standard oil clearance:

   Journal	Oil clearance
   Camshaft journal	0.030 to 0.067 mm (0.0012 to 0.0026 in.)
   Camshaft timing tube journal	0.036 to 0.057 mm (0.0014 to 0.0022 in.)

   Maximum oil clearance:

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

   1. If the oil clearance is greater than the maximum, replace the No. 3 camshaft and timing tube. If necessary, replace the bearing caps and cylinder head as a set.
      

9. Completely remove the Plastigage.
   

10. Remove the camshaft.
    

11. Remove the camshaft timing tube from the No. 3 camshaft.
    

Check the thrust clearance.

1. Install the camshaft timing tube to the No. 3 camshaft.
   

2. Install the No. 3 camshaft.
   

3. Using a dial indicator, measure the thrust clearance while moving the No. 3 camshaft back and forth.
   

   Standard thrust clearance:

   0.060 to 0.100 mm (0.0024 to 0.0039 in.)
   

   Maximum thrust clearance:

   0.13 mm (0.0051 in.)
   

   1. If the thrust clearance is greater than the maximum, replace the No. 3 camshaft. If necessary, replace the bearing caps and cylinder head as a set.
      

4. Remove the No. 3 camshaft.
   

5. Remove the camshaft timing tube from the No. 3 camshaft.
   

Check the gear backlash.

1. Install the drive gear to the camshaft timing tube.
   

2. Install the camshaft timing tube to the No. 3 camshaft.
   

3. Install the No. 3 camshaft and No. 4 camshaft without installing the camshaft sub-gear and front bearing cap.
   

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 (0.0188 in.)
   

   1. If the backlash is greater than the maximum, replace the drive gear and No. 4 camshaft.
      

Remove the No. 3 camshaft and No. 4 camshaft.

Remove the camshaft timing tube from the No. 3 camshaft.

Remove the drive gear from the camshaft timing tube.

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.





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

   NOTICE:

   Be careful not to scratch the cylinder block contact surface.





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





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

Inspect for flatness.

1. Using a precision straightedge and feeler gauge, measure the surfaces contacting the cylinder block and the manifolds for warpage.
   

   Maximum warpage:

   Item	Specified Condition
   Cylinder block surface	0.05 mm (0.0020 in.)
   Intake manifold surface	0.10 mm (0.0039 in.)
   Exhaust manifold surface	0.10 mm (0.0039 in.)

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

Inspect the cylinder head for cracks.

1. Using a dye penetrant, check the combustion chamber, intake ports, exhaust ports and cylinder block surface for cracks.
   

   1. If the cylinder head is cracked, replace it.
      

Clean the cylinder block.

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.
   

   NOTICE:

   If the cylinder is washed at high temperatures, the cylinder liner sticks out beyond the cylinder block. Always wash the cylinder block at a temperature of 45°C (113°F) or less.

Inspect for flatness.

1. Using a precision straightedge and feeler gauge, measure the surfaces contacting the cylinder head and main bearing cap for warpage.
   

   Maximum warpage:

   0.07 mm (0.0028 in.)
   

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

Visually check the cylinder for vertical scratches.
If deep scratches are present, replace the cylinder block.

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.

If deep scratches are present, replace the cylinder block.

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

   Standard diameter:

   Number Mark	Specified Condition
   Mark 1	91.000 to 91.008 mm (3.5827 to 3.5830 in.)
   Mark 2	91.008 to 91.021 mm (3.5830 to 3.5835 in.)
   Mark 3	91.021 to 91.029 mm (3.5835 to 3.5838 in.)

   Maximum diameter:

   91.149 mm (3.5885 in.)
   

   If the average of the diameter is greater than the maximum, replace the cylinder block.
   

   HINT:

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

Clean the piston.

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





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





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

   NOTICE:

   Do not use a wire brush.

Inspect the piston oil clearance.

HINT:

There are 3 standard diameter sizes, marked "1", "2" and "3". 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, 28.1 mm (1.106 in.) from the piston head.
   

   Piston diameter:

   Number Mark	Specified Condition
   Mark 1	90.910 to 90.920 mm (3.5791 to 3.5795 in.)
   Mark 2	90.920 to 90.928 mm (3.5795 to 3.5798 in.)
   Mark 3	90.928 to 90.938 mm (3.5798 to 3.5802 in.)

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





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

   Standard oil clearance:

   0.080 to 0.101 mm (0.0031 to 0.0040 in.)
   

   Maximum oil clearance:

   0.101 mm (0.0040 in.)
   

   If the oil clearance is greater than the maximum, replace all 8 pistons. 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 "3L" and the RH piston is marked with "3R".
      

Inspect the piston pin fit.

1. At 60°C (140°F), check that the piston pin can be pushed into the piston pin hole with your thumb.
   

Using a micrometer, measure the piston pin diameter.

Piston pin diameter:

21.997 to 22.006 mm (0.8660 to 0.8664 in.)

Inspect the piston ring groove clearance.

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

   Ring groove clearance:

   Piston Ring	Specified Condition
   No. 1	0.030 to 0.080 mm (0.0012 to 0.0031 in.)
   No. 2	0.020 to 0.060 mm (0.0008 to 0.0024 in.)

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

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.
   





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

   Standard end gap:

   End Gap	Specified Condition
   No. 1 piston ring	0.300 to 0.400 mm (0.0118 to 0.0157 in.)
   No. 2 piston ring	0.400 to 0.500 mm (0.0157 to 0.0197 in.)
   Oil ring (Side rail)	0.150 to 0.400 mm (0.0059 to 0.0157 in.)

   Maximum end gap:

   End Gap	Specified Condition
   No. 1 piston ring	1.10 mm (0.0433 in.)
   No. 2 piston ring	1.20 mm (0.0472 in.)
   Oil ring (Side rail)	1.10 mm (0.0433 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, replace the cylinder block.
   

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

1. Check if the connecting rod is bent.
   

   Maximum bend:

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

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




2. Check if the connecting rod is twisted.
   

   Maximum twist:

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

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

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.)
   

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

2. Subtract the piston pin diameter measurement from the bush 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 bush. If necessary, replace the piston and piston pin with a new piston and pin set.
   

Using a vernier caliper, measure the tension portion of the connecting rod bolt.

Standard diameter:

7.200 to 7.300 mm (0.2835 to 0.2874 in.)

Maximum diameter:

7.00 mm (0.2756 in.)

Using a vernier caliper, measure the tension portion diameter of the main bearing cap bolt.

Standard diameter:

7.500 to 7.600 mm (0.2953 to 0.2992 in.)

Maximum diameter:

7.20 mm (0.2835 in.)

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:

   0.08 mm (0.0031 in.)
   

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

Inspect the main journals and crank pins.

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

   Main 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 main 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.