Piston and Connecting Rod

Repair Procedures

Disassembly

Be careful not to damage parts located under the vehicle (floor under cover, fuel filter, fuel tank, and canister) when lifting the vehicle with a lift. (Refer to General Information - Jack Lifting Points and Support Points)

Use fender covers to avoid damaging painted surfaces. To prevent damage, carefully disconnect the wiring connectors while holding the connector housing.

Label all wires and hoses to avoid incorrect connection. Inspect the timing chain before removing the cylinder head. Turn the crankshaft pulley damper 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 expansion tank. (Refer to Intake and Exhaust System - "Expansion Tank")
7. 7
   Remove the intake manifold. (Refer to Intake and Exhaust Systems — Intake Manifold)
8. 8
   Remove the exhaust manifold. (Refer to Intake and Exhaust System - "Exhaust Manifold")
9. 9
   Remove the timing chain. (Refer to Valve Timing System - Timing Chain)
10. 10
    Remove the water temperature control unit. (Refer to Cooling System - "Water Temperature Control Assembly")
11. 11
    Remove the cylinder head assembly. (Refer to Cylinder Head Assembly - "Cylinder Head")
12. 12
    Remove the lower oil pan and upper oil pan. (Refer to Lubrication System - "Oil Pan")
13. 13
    Remove the oil pump. (Refer to Lubrication System - "Oil Pump")
14. 14
    Remove the oil filter housing. (Refer to Lubrication System - "Oil Filter Housing").
15. 15
    Remove the baffle (A).

    

16. 16
    Check the connecting rod side clearance.
17. 17
    Check the oil clearance of the connecting rod cap.
18. 18
    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 assembly so it can be reassembled in its original position.

19. 19
    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.

       Install the piston rings in the correct order only.

20. 20
    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 side 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 for 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] 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 be permanently stretched beyond the elastic limit 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: 0.042–0.060 mm (0.0017–0.0024 in)

      

   9. If the Plastigage shows the clearance is still incorrect, try the next larger or smaller bearing (color listed above or below this one) and check the clearance again.

      Do not grind, shim, or scratch 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 (color listed above or below this one) and check the clearance again.

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

       If the marks are illegible due to dirt and dust buildup, clean with solvent or detergent instead of rubbing with a wire brush or scraper.

       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 Identification

       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 reassembling, check the cylinder numbers on the connecting rod and cap. When installing a new connecting rod, the bearing mounting notches on the rods and caps must face the same direction.
   2. If one or both thrust surfaces of the connecting rod are damaged, replace the rod. If the inner surface of the rod is damaged or rough, also replace it.
   3. Using a connecting rod alignment fixture, measure the bend and twist of the rod. If the measurement is close to specification, adjust the rod using a press. If the rod is excessively 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 the bearing, there must 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 diameter and the piston outer diameter.

   Clearance: 0.04–0.06 mm (0.0016–0.0024 in)

   1. Using a cylinder bore gauge, measure the cylinder diameter in the thrust direction and in the axial direction.

      Standard diameter: 96.00–96.03 mm (3.7795–3.7807 in)

      

   2. Measure the outer diameter of the piston at a distance of 14 mm (0.55118 in) from the bottom of the piston.

      Standard diameter: 95.95–95.98 mm (3.7776–3.7787 in)

      

6. 6
   Select the piston according to the cylinder bore diameter class.

   Clearance: 0.04–0.06 mm (0.0016–0.0024 in)

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

      

      Cylinder Bore Diameter Identification

      Grade	Size code	Cylinder Inner Diameter
      A	A	96.00–96.01 mm (3.7795–3.7799 in)
      B	B	96.01–96.02 mm (3.7799–3.7803 in)
      C	C	96.02–96.03 mm (3.7803–3.7807 in)

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

      

      Piston Outer Diameter Identification

      Grade	Size code	Piston Outer Diameter
      A	A	95.95–95.96 mm (3.7776–3.7779 in)
      B	B	95.96–95.97 mm (3.7779–3.7783 in)
      C	C	95.97–95.98 mm (3.7783–3.7787 in)

7. 7
   Check 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: 0.02–0.06 mm (0.0008–0.0024 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, carefully pressing it in with the piston. Measure the gap with a feeler gauge. If the gap exceeds the service limit, replace the piston ring. If the gap is too large, re-check the cylinder bore diameter for wear limits. If the bore diameter exceeds the service limit, the cylinder block must be replaced. Piston ring end gap Standard: No.1: 0.17–0.24 mm (0.0067–0.0094 in) No.2: 0.32–0.47 mm (0.0126–0.0185 in) Oil ring: 0.20–0.40 mm (0.0078–0.0157 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: 21.097–22.000 mm (0.8306–0.8661 in)

   

10. 10
    Measure the piston pin-to-piston clearance.

    Piston pin-to-piston clearance: 0.004–0.013 mm (0.00015–0.00051 in)

11. 11
    Check 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 the parts, apply fresh 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 two snap rings and check that the snap rings are securely seated.
   2. The front mark of the piston (A) and the front mark of the connecting rod (B) must face the engine 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 tab with the groove in the connecting rod or connecting rod cap.
   2. Install the bearings (A) in the connecting rod and connecting rod cap (B).

      

      When assembling the connecting rods and caps, check the front marks and the cylinder number.

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

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

   1. Install the piston ring compressor and make sure the bearing is securely in place. Then insert the piston into the cylinder and push it in using the wooden handle of a hammer.
   2. Stop when the ring compressor is released, and check the alignment of the rod with the crankpin before inserting the piston into position.
   3. Install the connecting rod caps with bearings and 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 be permanently stretched beyond the elastic limit during tightening. If the bolts are removed and reused, they may break or fail to maintain clamping force. Maintain downward force on the ring compressor so the rings do not expand before entering the cylinder bore.

      

5. 5
   Install the baffle plate. Install and tighten the baffle plate bolts evenly in multiple passes in the sequence shown.

   Tightening torque: 9.8–11.8 N·m

   

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