Piston and Connecting Rod Repair Procedures

Disassembly

Use fender covers to avoid damaging painted surfaces. To avoid damage, carefully disconnect the wiring connectors by holding the connector body.

Label all wires and hoses to avoid incorrect connection. Inspect the timing chain before removing the cylinder head. Turn the crankshaft pulley so that the No. 1 piston is at top dead center (TDC).

1. 1
   Remove the engine assembly from the vehicle. (Refer to Engine and Transaxle Assembly - "Engine and Transaxle Assembly")
2. 2
   Remove the transaxle assembly from the engine assembly. (Refer to Automatic Transaxle System - "Automatic Transaxle")
3. 3
   Remove the drive plate and adapter plate. (Refer to Cylinder Block - "Drive Plate")
4. 4
   Remove the rear oil seal retainer. (Refer to Cylinder Block - "Rear Oil Seal")
5. 5
   Install the engine assembly on an engine stand for disassembly.
6. 6
   Remove the exhaust manifold. (Refer to Intake and Exhaust System - "Exhaust Manifold")
7. 7
   Remove the intake manifold. (Refer to Intake and Exhaust Systems — Intake Manifold)
8. 8
   Remove the timing chain. (Refer to Valve Timing System - Timing Chain)
9. 9
   Remove the water temperature control unit. (Refer to Cooling System - "Water Temperature Control Assembly")
10. 10
    Remove the cylinder head. (Refer to Cylinder Head Assembly - "Cylinder Head")
11. 11
    Remove the oil pump. (Refer to Lubrication System - "Oil Pump")
12. 12
    Remove the oil filter housing. (Refer to Lubrication System - "Oil Filter Housing").
13. 13
    Remove the upper oil pan. (Refer to Lubrication System - "Oil Pan")
14. 14
    Remove the baffle (A).

    

15. 15
    Check the connecting rod side clearance.
16. 16
    Check the oil clearance of the connecting rod cap.
17. 17
    Disconnect the piston and connecting rod assembly from the cylinder block.

    1. Using a ridge reamer, remove all carbon from the upper part of the cylinder.
    2. Remove the connecting rod bearing cap.

       Mark the connecting rod and caps so they can be reassembled in their original position and direction.

    3. Push the piston, connecting rod assembly, and upper bearing out through the top of the cylinder block.

    Keep the bearings, connecting rod, and cap together. Arrange the piston and connecting rod assemblies in the correct order. Mark the piston and connecting rod assemblies so they can be reassembled in their original positions.

18. 18
    Disassemble the piston rings.

    1. Using a piston ring expander, remove the 2 compression rings (A).
    2. Remove the oil control ring and expander spring (B) by hand.

    Arrange the piston rings only in the correct order.

19. 19
    Remove the connecting rod from the piston.

    1. Remove the snap ring (C) from the piston.
    2. Using a press, remove the piston pin (D) from the piston.
    3. Disassemble the piston (F) and connecting rod (E).

    

Inspection

1. 1
   Inspect the connecting rod side clearance. Using a feeler gauge, measure the side clearance while moving the connecting rod back and forth.

   Standard clearance: 0.1 ~ 0.25 mm (0.004 ~ 0.010 in.)

   

   • If out of specification, install a new connecting rod.
   • If still out of specification, replace the crankshaft.
2. 2
   Check the connecting rod bearing oil clearance.

   1. Make sure the alignment marks on the connecting rod and cap are aligned to ensure correct assembly.
   2. Remove the 2 connecting rod cap bolts.
   3. Remove the connecting rod cap and bearing half.
   4. Clean the connecting rod journal and bearing.
   5. Place a piece of Plastigage across the connecting rod journal.
   6. Install the bearing half and cap, then tighten the bolts. Tightening torque: [27.5 ~ 31 N·m] + [68 ~ 72°]

      

      Do not rotate the crankshaft. Always use new connecting rod cap bolts. Connecting rod cap bolts are torque-to-yield bolts designed to stretch permanently beyond the elastic range when tightened. If the bolts are removed and reused, they may break or fail to maintain clamping force.

   7. Remove the 2 bolts, the connecting rod cap and the bearing half.
   8. Measure the Plastigage at its widest point.

      Standard oil clearance: 0.040 ~ 0.062 mm (0.0016 ~ 0.0024 in.)

      

   9. If the Plastigage is too wide or too narrow, remove the upper bearing half, install a new bearing with the same color mark (select the color as shown in the following column), and recheck the clearance.

      Do not grind, shim or scrape the bearings or caps to adjust the clearance.

   10. If the Plastigage shows the clearance is still incorrect, try the next larger or smaller bearing (the color above or below the one specified) and recheck the clearance.

       If the proper clearance cannot be obtained using bearings of larger or smaller size, replace the crankshaft and start over.

       If the markings are illegible due to dirt and dust buildup, do not scrape them off or use a wire brush. Clean them only with solvent or detergent.

       Location of connecting rod mark

       

       Connecting Rod Identification

       Grade	Mark	Inner Diameter
       0	a	58.000 ~ 58.006 mm (2.2834 ~ 2.2837 in.)
       1	D	58.006 ~ 58.012 mm (2.2837 ~ 2.2839 in.)
       2	c	58.012 ~ 58.018 mm (2.2839 ~ 2.2842 in.)

       
       Location of crankshaft pin mark Crankshaft Identification

       

       Crankshaft Journal Diameter

       Grade	Mark	Pin Outside Diameter
       I	1 or A	54.966 ~ 54.972 mm (2.1640 ~ 2.1642 in.)
       II	2 or B	54.960 ~ 54.966 mm (2.1638 ~ 2.1640 in.)
       III	3 or C	54.954 ~ 54.960 mm (2.1635 ~ 2.1638 in.)

       
       Identification mark location (connecting rod bearing)

       

       Connecting Rod Bearing Identification

       Grade	Mark	Bearing Thickness
       E	Blue	1.509 ~ 1.512 mm (0.0594 ~ 0.0595 in.)
       D	Black	1.506 ~ 1.509 mm (0.0592 ~ 0.0594 in.)
       C	Red	1.503 ~ 1.506 mm (0.0591 ~ 0.0592 in.)
       B	Green	1.500 ~ 1.503 mm (0.0590 ~ 0.0591 in.)
       A	Yellow	1.497 ~ 1.500 mm (0.0589 ~ 0.0590 in.)

   11. Selection

       		Connecting Rod Marking
       		0 (a)	1 (b)	2 (c)
       Crankshaft Marking	1 or A	A (Yellow)	B (Green)	C (Red)
       	2 or B	B (Green)	C (Red)	D (Black)
       	3 or C	C (Red)	D (Black)	E (Blue)

3. 3
   Inspect the connecting rod.

   1. When reinstalling, check the cylinder numbers on the connecting rods and caps. When installing a new connecting rod, the bearing locking grooves on the connecting rods and caps must face the same direction.
   2. If one or both edges of the connecting rod thrust surface are damaged, replace the connecting rod. If the inner surface of the connecting rod is damaged or rough, also replace it.
   3. Using a connecting rod aligner, measure the bend or twist of the rod. If the measurement is close to the specification, correct the rod using a press. If the rod is severely bent or twisted, replace it. Maximum connecting rod bend: 0.05 mm/100 mm (0.0020 in./3.9370 in.) Maximum connecting rod twist: 0.1 mm/100 mm (0.0039 in./3.9370 in.)

      When assembling the connecting rod without a bearing, there should be no difference.

4. 4
   Clean the piston

   1. Using a gasket scraper, remove carbon deposits from the top of the piston.
   2. Using a ring groove cleaning tool, clean the piston ring grooves.
   3. Using solvent and a brush, thoroughly clean the piston.

      Do not use a wire brush.

5. 5
   Check the piston-to-cylinder clearance by calculating the difference between the cylinder bore inside diameter and the piston outside diameter.

   Clearance: 0.03 ~ 0.05 mm (0.0012 ~ 0.0020 in.)

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

      Standard diameter: 92.00 ~ 92.03 mm (3.6220 ~ 3.6232 in.)

      

   2. Measure the piston outside diameter at 14 mm (0.55118 in.) from the bottom edge of the piston.

      Standard diameter: 91.96 ~ 91.99 mm (3.6204 ~ 3.6216 in.)

      

6. 6
   Select a piston that matches the cylinder bore size class.

   Clearance: 0.03 ~ 0.05 mm (0.0012 ~ 0.0020 in.)

   1. Check the cylinder bore size code on the cylinder block.

      

      Cylinder Bore Diameter Grades

      Grade	Size code	Cylinder Inner Diameter
      A	A	92.00 ~ 92.01 mm (3.6220 ~ 3.6224 in.)
      B	B	92.01 ~ 92.02 mm (3.6224 ~ 3.6228 in.)
      C	C	92.02 ~ 92.03 mm (3.6228 ~ 3.6232 in.)

   2. Check the piston size code (A) and front mark (B) on the top surface of the piston.

      

      Piston Outside Diameter Grades

      Grade	Size code	Piston Outer Diameter
      A	A	91.96 ~ 91.97 mm (3.6204 ~ 3.6208 in.)
      B	B	91.97 ~ 91.98 mm (3.6208 ~ 3.6212 in.)
      C	C	91.98 ~ 91.99 mm (3.6212 ~ 3.6216 in.)

7. 7
   Inspect the piston ring side clearance. Using a feeler gauge, measure the clearance between a new piston ring and the ring groove wall. Piston Ring Side Clearance Standard No. 1: 0.04 ~ 0.08 mm (0.0015 ~ 0.0031 in.) No. 2: 0.04 ~ 0.08 mm (0.0015 ~ 0.0031 in.) Oil ring: 0.06 ~ 0.15 mm (0.0024 ~ 0.0059 in.) Limit No. 1: 0.1 mm (0.004 in.) No. 2: 0.1 mm (0.004 in.) Oil ring: 0.2 mm (0.008 in.)

   

   If the clearance is greater than the maximum, replace the piston.
8. 8
   Inspect the piston ring end gap. To measure the piston ring end gap, insert the piston ring into the cylinder bore. Position the ring at a right angle to the cylinder wall by carefully pushing it down with the piston. Measure the gap using a feeler gauge. If the gap exceeds the limit, replace the piston ring. If the gap is too large, recheck the cylinder bore diameter against the wear limit. If the bore diameter exceeds the service limit, the cylinder block must be replaced. Piston Ring End Gap Standard No. 1: 0.17 ~ 0.32 mm (0.0067 ~ 0.0126 in.) No. 2: 0.37 ~ 0.52 mm (0.0145 ~ 0.0204 in.) Oil ring (with expander): 0.20 ~ 0.70 mm (0.0078 ~ 0.0276 in.) Oil ring (non-expander type): 0.20 ~ 0.50 mm (0.0078 ~ 0.0196 in.) Limit No. 1: 0.6 mm (0.0236 in.) No. 2: 0.7 mm (0.0275 in.) Oil ring: 0.8 mm (0.0315 in.)

   

9. 9
   Measure the piston pin diameter.

   Piston pin diameter: 21.997 ~ 22.000 mm (0.8660 ~ 0.8661 in.)

   

10. 10
    Measure the clearance between the piston pin and the piston. Piston pin to piston clearance: 0.004 ~ 0.013 mm (0.00015 ~ 0.00051 in.)
11. 11
    Measure the difference between the piston pin diameter and the connecting rod small end bore diameter. Piston pin to connecting rod interference: 0.005 ~ 0.019 mm (0.00019 ~ 0.00074 in.)

Installation

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

1. 1
   Assemble the piston and connecting rod.

   1. Install the piston pin with the 2EA snap ring and carefully check the snap ring assembly.
   2. The front mark on the piston (A) and the front mark on the connecting rod (B) must face the engine toward the timing belt side.

      

2. 2
   Install the piston rings.

   1. Install the cylindrical spring and oil control ring by hand.
   2. Using a piston ring expander, install the 2 compression rings with the code mark facing up.
   3. Position the piston rings so that the ring end gaps are as shown in the illustration.

      

3. 3
   Install the connecting rod bearings.

   1. Align the bearing tang with the groove in the connecting rod or connecting rod cap.
   2. Install the bearings (A) into the connecting rod and the connecting rod cap (B).

      

      When assembling the connecting rods and caps, make sure the front marks and cylinder number are aligned.

4. 4
   Install the piston and connecting rod assembly to the cylinder block.

   Before installing the pistons, apply a coat of engine oil to the ring grooves and cylinder bores.

   1. Install the ring compressor, make sure the bearing is securely in place, then place the piston into the cylinder and tap it in using the wooden handle of a hammer.
   2. Stop after the ring compressor is released, and check the connecting rod and journal alignment before inserting the piston into position.
   3. Install the connecting rod caps with bearings, then tighten the bolts. Tightening torque: [27.5 ~ 31 N·m] + [68 ~ 72°]

      Always use new connecting rod cap bolts. Connecting rod cap bolts are torque-to-yield bolts designed to stretch permanently beyond the elastic range when tightened. If the bolts are removed and reused, they may break or fail to maintain clamping force. Maintain downward pressure on the ring compressor to prevent the rings from expanding before they enter the cylinder bore.

      

      Using SST (09221-4A000), install the connecting rod bearing cap bolts.

      

5. 5
   Install the baffle plate. Install and evenly tighten the baffle plate bolts in several passes in the specified sequence.

   Tightening torque: 9.8 ~ 11.8 N·m

   

6. 6
   Assemble the remaining components in the reverse order of removal.