Engine Mechanical Cylinder Block: Inspection

CLEAN CYLINDER BLOCK
1. Remove the gasket material.
  Using a gasket scraper, remove all the gasket material from the top surface of the cylinder block.
  
  Fig 1: Removing Gasket Material From Top Surface Of Cylinder Block Using A Gasket Scraper
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Clean the cylinder block.
  Using a soft brush and solvent, thoroughly clean the cylinder block.
NOTE: If the cylinder is washed at high temperatures, the cylinder liner sticks out beyond the cylinder block, so always wash the cylinder block at a temperature of 45°C (133°F) or less.
INSPECT CYLINDER BLOCK
1. Inspect for flatness.
  
  Fig 2: Inspect Cylinder Block For Flatness
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Using a precision straight edge and a feeler gauge, measure the surface contacting the cylinder head gasket for warpage.
  
  Maximum warpage: 0.08 mm (0.0031 in.)
  
  If warpage is greater than maximum, replace the cylinder block.
2. Visually check the cylinder for vertical scratches.
  
  Fig 3: Identifying Cylinder Vertical Scratches
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  If deep scratches are present, replace the cylinder block.
3. Inspect the cylinder bore diameter.
  Using a cylinder gauge, measure the cylinder bore diameter at positions A, B and C in the thrust and axial directions.
  
  Fig 4: Measuring Cylinder Bore Diameter Using A Cylinder Gauge
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Standard diameter:
  
  86.000 - 86.013 mm (3.3858 - 3.3863 in.)
  
  Maximum diameter: 86.013 mm (3.3863 in.)
  
  If the diameter is greater than maximum, replace the cylinder block.
REMOVE 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 5: Removing Cylinder Ridge
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
INSPECT CRANKSHAFT BEARING CAP BOLTS
Using vernier calipers, measure the tension portion diameter of the bolt.

Fig 6: Measuring Tension Portion Diameter Of Bolt Using Vernier Calipers
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Standard diameter: 7.5 - 7.6 mm (0.2953 - 0.2992 in.)

Minimum diameter: 7.2 mm (0.284 in.)

If the diameter is less than minimum, replace the bolt.
CLEAN PISTON
1. Using a gasket scraper, remove the carbon from the piston top.
  
  Fig 7: Removing Carbon From Piston Top Using A Gasket Scraper
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
2. Using a groove cleaning tool or a broken ring, clean the piston ring grooves.
  
  Fig 8: Cleaning Piston Ring Grooves Using A Groove Cleaning Tool
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
3. Using a brush and solvent, thoroughly clean the piston.
NOTE: Do not use a wire brush.

INSPECT PISTON

Inspect the piston oil clearance.
1. Using a micrometer, measure the piston diameter at right angles to the piston pin center line, 30.4 mm (1.1968 in.) from the piston head.
  
  Fig 10: Measuring Piston Diameter At Right Angles To Piston Pin Center Line
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  
  Piston diameter:
  
  85.927 - 85.937 mm (3.3829 - 3.3833 in.)
2. Measure the cylinder bore diameter in the thrust directions (See step b).
3. Subtract the piston diameter measurement from the cylinder bore diameter measurement.
Standard oil clearance:

0.063 - 0.086 mm (0.0025 - 0.0034 in.)

Maximum oil clearance: 0.10 mm (0.0039 in.)

If the oil clearance is greater than maximum, replace all the 4 pistons. If necessary, replace the cylinder block.

Inspect the piston ring groove clearance.

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

Fig 11: Measuring Clearance Between Piston Ring & Ring Groove Wall Using A Feeler Gauge

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

RING GROOVE CLEARANCE

No. 1	0.020 - 0.070 mm (0.0008 - 0.0028 in.)
No. 2	0.020 - 0.060 mm (0.0008 - 0.0024 in.)
Oil (Side rail)	0.070 - 0.150 mm (0.0028 - 0.0059 in.)

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

Inspect the piston ring end gap.

Fig 12: Identifying Piston Ring End Gap

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Insert the piston ring into the cylinder bore.
Using the piston, push the piston ring a little beyond the bottom of the ring travel, 110 mm (4.33 in.) from the top of the cylinder block.
Using a feeler gauge, measure the end gap.

Fig 13: Measuring End Gap Using A Feeler Gauge

Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

STANDARD END GAP SPECIFICATIONS

No. 1	0.30 - 0.40 mm (0.0118 - 0.0157 in.)
No. 2	0.47 - 0.62 mm (0.0185 - 0.0244 in.)
Oil (side rail)	0.10 - 0.35 mm (0.0039 - 0.0138 in.)

MAXIMUM END GAP SPECIFICATIONS

No. 1	0.89 mm (0.0350 in.)
No. 2	1.37 mm (0.0539 in.)
Oil (side rail)	0.73 mm (0.0287 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.

Inspect the piston pin fit.

Fig 14: Inspecting Piston Pin Fit
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

At 80 - 90°C (176 - 194°F), you should be able to push the piston pin into the piston pin hole with your thumb.

INSPECT CONNECTING ROD
1. Using a rod aligner and a feeler gauge, check the connecting rod alignment.
  
  Fig 15: Checking Connecting Rod Alignment Using A Rod Aligner & A Feeler Gauge
  Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
  1. Check for out-of-alignment.
    Maximum out-of-alignment:
    
    0.05 mm (0.0020 in.) per 100 mm (3.94 in.)
    
    If out-of-alignment is greater than maximum, replace the connecting rod assembly.
  2. Check for twist.
    
    Fig 16: Checking Connecting Rod Twist
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    
    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.
2. Inspect the piston pin oil clearance.
  1. Using a caliper gauge, measure the inside diameter of the connecting rod bushing.
    
    Fig 17: Measuring Connecting Rod Bushing Inside Diameter Using A Caliper Gauge
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    
    Bushing inside diameter:
    
    22.005 - 22.014 mm (0.8663 - 0.8667 in.)
  2. Using a micrometer, measure the piston pin diameter.
    
    Fig 18: Measuring Piston Pin Diameter Using A Micrometer
    Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002
    
    Piston pin diameter:
    
    21.997 - 22.006 mm (0.8660 - 0.8664 in.)
  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 (See REPLACEMENT ). If necessary, replace the piston and piston pin as a set.
INSPECT CONNECTING ROD BOLTS
Using vernier calipers, measure the tension portion diameter of the bolt.

Fig 19: Measuring Tension Portion Diameter Of Bolt Using Vernier Calipers
Courtesy of © TOYOTA, LICENSE AGREEMENT TMS1002

Standard diameter: 7.2 - 7.3 mm (0.283 - 0.287 in.)

Minimum diameter: 7.0 mm (0.276 in.)

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

INSPECT CRANKSHAFT

Inspect for circle runout.
1. Place the crankshaft on V-blocks.
2. Using a dial indicator, measure the circle runout, as shown in the illustration.
Maximum circle runout: 0.03 mm (0.0012 in.)

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

Inspect the main journals and crank pins.

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

Fig 21: Measuring Main Journal & Crank Pin Diameter Using A Micrometer

MAIN JOURNAL AND CRANK PIN DIAMETER SPECIFICATIONS

Main journal	54.988 - 55.000 mm (2.1649 - 2.1654 in.)
Crank pin	47.990 - 48.000 mm (1.8894 -1.8898 in.)

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

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

Maximum taper and out-of-round:

0.003 mm (0.0001 in.)

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