Cylinder Block: Inspection

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.
   Fig 1: Cleaning Cylinder Block

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1. Inspect for flatness.

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

   Maximum warpage: 0.07 mm (0.0028 in.) 

   Fig 2: Measuring Surface Contacting Cylinder Head And Main Bearing Cap For Warpage

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

2. Visually check the cylinder for vertical scratches.

   If deep scratches are present, replace the cylinder block.

   Fig 3: Visually Checking Cylinder Block For Vertical Scratches

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3. Inspect the cylinder bore diameter.
   Fig 4: Inspecting Cylinder Bore Diameter

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   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.

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

   Fig 5: Measuring Cylinder Bore Diameter

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   Standard diameter: 

   CYLINDER BORE DIAMETER SPECIFICATION
   
   

   Mark "1"	91.000 - 91.008 mm (3.5827 - 3.5830 in.)
   Mark "2"	91.008 - 91.021 mm (3.5830 - 3.5835 in.)
   Mark "3"	91.021 - 91.029 mm (3.5835 - 3.5838 in.)

   Maximum diameter: 91.14 mm (3.5925 in.) 

   If the average diameter of 4 position is greater than maximum, replace the cylinder block.

4. Remove the cylinder ridge.

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

   Fig 6: Removing Cylinder Ridge

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5. Using vernier calipers, measure the tension portion diameter of the main bearing cap bolt.

   Standard diameter: 7.500 - 7.600 mm (0.2953 - 0.2992 in.) 

   Minimum diameter: 7.20 mm (0.2835 in.) 

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

Fig 7: Measuring Tension Portion Diameter Using Vernier Calipers

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1. Using a gasket scraper, remove the carbon from the piston top.
   Fig 8: Removing Carbon From Piston Top Using Gasket Scraper

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2. Using a groove cleaning tool or broken ring, clean the piston ring grooves.
   Fig 9: Cleaning Piston Ring Grooves

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

Fig 10: Cleaning Piston Using Solvent And Brush

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1. Inspect the piston oil clearance.
   Fig 11: Inspecting Piston Oil Clearance

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   HINT:

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

      Piston diameter: 

      PISTON DIAMETER SPECIFICATION
      
      

      Mark "1"	90.910 - 90.940 mm (3.5791 - 3.5803 in.)
      Mark "2"	90.920 - 90.948 mm (3.5795 - 3.5806 in.)
      Mark "3"	90.928 - 90.958 mm (3.5798 - 3.5810 in.)

   2. Measure the cylinder bore diameter in the thrust directions. (See step  2 above)
   3. Subtract the piston diameter measurement from the cylinder bore diameter measurement.

   Standard oil clearance: 

   0.060 - 0.101 mm (0.0023 - 0.0040 in.) 

   Maximum oil clearance: 0.121 mm (0.0048 in.) 

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

   HINT

   Use new cylinder block:

   • Use a piston with the same number mark as the cylinder diameter marked on the cylinder block.
   • The shape of the piston varies for the LH and RH banks. The LH piston is marked with "3L", the RH piston with "3R".
   Fig 12: Using New Cylinder Block

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2. Inspect the piston ring groove clearance.

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

   Fig 13: Measuring Clearance Between New Piston Ring & Wall

   Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

   Ring groove clearance: 

   RING GROOVE CLEARANCE SPECIFICATION
   
   

   No.1	0.030 - 0.080 mm (0.0012 - 0.0031 in.)
   No.2	0.020 - 0.060 mm (0.0008 - 0.0024 in.)

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

3. 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.
      Fig 14: Inspecting Piston Ring End Gap

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   3. Using a feeler gauge, measure the end gap.
      Fig 15: Measuring End Gap With Feeler Gauge

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   Standard end gap: 

   PISTON RING STANDARD END CAP SPECIFICATION
   
   

   No.1	0.300 - 0.500 mm (0.0118 - 0.0197 in.)
   No.2	0.400 - 0.600 mm (0.0157 - 0.0236 in.)
   Oil (Side rail)	0.150 - 0.500 mm (0.0059 - 0.0197 in.)

   Maximum end gap: 

   PISTON RING MAXIMUM END CAP SPECIFICATION
   
   

   No.1	1.10 mm (0.0433 in.)
   No.2	1.20 mm (0.0472 in.)
   Oil (Side rail)	1.10 mm (0.0433 in.)

   If the end gap is greater than maximum, replace the piston ring. If the end gap is greater than maximum, even with a new piston ring, replace the cylinder block.

4. Inspect the piston pin fit.

   At 60°C (140°F), you should be able to push the piston pin into the piston pin hole with your thumb.

   Fig 16: Inspecting Piston Pin Fit

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5. 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 maximum, replace the connecting rod assembly.

      Fig 17: Checking Connecting Rod Alignment

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   2. Check for twist

      Maximum twist: 

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

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

      Fig 18: Checking Connecting Rod For Twist

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6. 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 - 22.014 mm (0.8663 - 0.8667 in.) 

      Fig 19: Inspecting Piston Pin Oil Clearance

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

      Piston pin diameter: 

      21.997 - 22.006 mm (0.8660 - 0.8664 in.) 

      Fig 20: Measuring Piston Pin Diameter Using Micrometer

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

      Standard oil clearance: 

      0.005 - 0.011 mm (0.0002 - 0.0004 in.) 

      Maximum oil clearance: 0.05 mm (0.0020 in.) 

   If the oil clearance is greater than maximum, replace the bushing. If necessary, replace the piston and piston pin as a set.

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

   Standard diameter: 

   7.200 - 7.300 mm (0.2835 - 0.2874 in.) 

   Minimum diameter: 7.00 mm (0.2756 in.) 

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

   Fig 21: Measuring Tension Portion Of Connecting Rod Bolt Using Vernier Calipers

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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: 0.08 mm (0.0031 in.) 

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

   Fig 22: Measuring Circle Runout Using Dial Indicator

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2. 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 - 67.000 mm (2.6373 - 2.6378 in.) 

      Crank pin diameter: 

      51.982 - 52.000 mm (2.0465 - 2.0472 in.) 

      Fig 23: Measuring Diameter Of Each Main Journal And Crank Pin

      Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

      If the diameter is not as specified, check the oil clearance (See DISASSEMBLY  ). If necessary, replace the crankshaft.

   2. Check each main journal and crank pin for taper and out-of-round as shown in Fig 23.

   Maximum taper and out-of-round: 

   0.02 mm (0.0008 in.) 

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