Kia Picanto JA Quiz
Engine Mechanical System

Piston and Connecting Rod

In this manual: Engine Mechanical System
General Information — 8Maintenance — 30Engine Mechanical System — 46Engine Electrical System — 14Emission Control System — 11Engine Control System/Fuel System — 46Clutch System — 12Manual Transmission — 10Drive Shaft and Axle — 8Suspension System — 15Steering — 9Restraints — 17Brake System — 22Body (Interior and Exterior) — 104Body Electrical System — 80Heating, Ventilation, and Air Conditioning — 17
35steps
~210min
4/5difficulty
0102030405014.711N·mlb·ft
Tightening torque found on this page
Done 0 of 35

Repair Procedures

Disassembly

  1. Remove the engine and transaxle assembly. (Refer to Engine and Transaxle Assembly - "Engine and Transaxle Assembly")
  2. Remove the transaxle assembly from the engine assembly. (See Manual Transaxle System - Manual Transaxle)
  3. Remove the flywheel. (Refer to Cylinder Block Assembly - "Flywheel")
  4. Remove the rear oil seal. (Refer to Cylinder Block Assembly - "Rear Oil Seal")
  5. Install the engine assembly on an engine stand for disassembly.
  6. Remove the cylinder head cover. (Refer to Cylinder Head Assembly - Cylinder Head Cover)
  7. Remove the thermostat housing. (Refer to Cooling System - "Thermostat")
  8. Remove the timing chain. (Refer to Valve Timing System - Timing Chain)
  9. Remove the intake manifold. (Refer to Intake and Exhaust Systems — Intake Manifold)
  10. Remove the turbocharger manifold module. (Refer to Intake and Exhaust System - "Turbocharger Manifold Module")
  11. Remove the cylinder head. (Refer to Cylinder Head Assembly - "Cylinder Head")
  12. Remove the oil pan and oil screen. (Refer to Lubrication System - "Oil Pan")
  13. Remove the ladder frame. (Refer to Cylinder Block - "Cylinder Block")
  14. Check the connecting rod side clearance.
  15. Check the oil clearance of the connecting rod bearing cap.
  16. Remove the piston and connecting rod assembly.
    1. Using a ridge reamer, remove all carbon from the upper part of the cylinder.
    2. Remove the connecting rod caps (A).
    3. Push the piston, connecting rod assembly, and upper bearing out through the top of the cylinder block.
  17. Check the fit between the piston and piston pin. Try moving the piston back and forth on the piston pin. If any movement is felt, replace the piston and pin as a set.
  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.
  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

Connecting Rod
  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: 0.10–0.25 mm (0.0039–0.0098 in.)

    1. If out of specification, install a new connecting rod.
    2. If still out of specification, replace the crankshaft.
  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 lower bearing.
    4. Clean the connecting rod journal and bearing.
    5. Place a piece of Plastigage on the crankshaft journal.
    6. Install the lower bearing and cap onto the connecting rod, then tighten the bolts.

      Tightening torque: 10.8–14.7 N·m + 88–92°

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

      Standard oil clearance: 0.018–0.036 mm (0.0007–0.0014 in.)

    9. If the Plastigage is too wide or too narrow, remove the upper and lower bearings, then install new bearings with the same color code. Recheck the oil clearance.
    10. If the Plastigage still indicates incorrect clearance, try the next larger or smaller size bearing. (Refer to the connecting rod bearing selection table.) Recheck the oil clearance.
    11. Select the bearing from the selection table. Connecting rod mark location
      Connecting Rod Identification
      Rating Mark Connecting rod inside diameter
      0 A 42.000 - 42.006 mm
      (1.6535–1.6540 in.)
      1 B 42.006 - 42.012 mm
      (1.6537–1.6540 in.)
      2 C 42.012 - 42.018 mm
      (1.6540–1.6542 in.)

      Crankshaft journal mark location
      Crankshaft journal identification
      Grade Mark Crankshaft Journal Outer Diameter
      I 1 38.966 - 38.972 mm
      (1.5340–1.5343 in.)
      II 2 38.960 - 38.966 mm
      (1.5338–1.5340 in.)
      III 3 38.954 - 38.960 mm
      (1.5336–1.5338 in.)

      Connecting rod bearing mark location
      Connecting Rod Bearing Identification
      Rating Color Connecting Rod Bearing Thickness
      A Blue 1.514 - 1.517 mm
      (0.0596–0.0597 in.)
      B Black 1.511 - 1.514 mm
      (0.0595–0.0596 in.)
      C None 1.508 - 1.511 mm
      (0.0594–0.0595 in.)
      D Green 1.505 - 1.508 mm
      (0.0593–0.0594 in.)
      E Yellow 1.502 - 1.505 mm
      (0.0591–0.0593 in.)
    12. Select the bearing from the selection table. Connecting rod bearing selection table
      Connecting Rod Bearing Connecting Rod Mark
      0(A) 1(B) 2(C)
      Crankshaft Journal Mark I (1) E (Yellow) D (green) C (None)
      II(2) D (green) C (None) B (Black)
      III(3) C (None) B (Black) Blue)
  3. Clean the piston
    1. Using a gasket scraper, remove carbon deposits from the top of the piston.
    2. Using a ring groove cleaner or a broken piston ring, clean the piston ring grooves.
    3. Using solvent and a brush, thoroughly clean the piston.
  4. Check the piston-to-cylinder clearance by calculating the difference between the cylinder bore inside diameter and the piston outside diameter.

    Piston-to-cylinder clearance: 0.025–0.045 mm (0.0010–0.0018 in.)

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

      Standard diameter: 71.00–71.03 mm (2.7952–2.7964 in.)

    2. Measure the standard piston outside diameter at a point 30 mm (1.18 in.) from the top surface of the piston.

    Standard diameter: 70.965–70.995 mm (2.7939–2.7951 in.)

  5. Select a piston that matches the cylinder bore size class.
    1. Check the cylinder bore size code on the side of the cylinder block.
      Cylinder Inner Diameter
      Grade Mark Inner Diameter
      a A 71.00 - 71.01 mm
      (2.79528 - 2.79567 in.)
      D B 71.01 - 71.02 mm
      (2.79567 - 2.79606 in.)
      c C 71.02 - 71.03 mm
      (2.79606 - 2.79646 in.)
    2. Check the piston size mark on the piston top surface.
      Piston Outer Diameter
      Grade Mark Inner Diameter
      a A 70.965 - 70.975 mm
      (2.79390 - 2.79429 in.)
      D B 70.975 - 70.985 mm
      (2.79429 - 2.79469 in.)
      c C 70.985 - 70.995 mm
      (2.79469 - 2.79508 in.)
  6. 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 groove width: No. 1: 1.235–1.250 mm (0.0486–0.0492 in.) No. 2: 1.23–1.25 mm (0.0484–0.0492 in.) Oil ring: 2.010–2.025 mm (0.0791–0.0797 in.) Piston ring width: No. 1: 1.170–1.185 mm (0.0461–0.0467 in.) No. 2: 1.17–1.19 mm (0.0460–0.0468 in.) Oil ring: 1.90–1.96 mm (0.0748–0.0772 in.) Piston ring side clearance: No. 1: 0.05–0.08 mm (0.0020–0.0031 in.) No. 2: 0.04–0.08 mm (0.0015–0.0031 in.) Oil ring: 0.050–0.125 mm (0.0020–0.0049 in.)
    If the clearance is greater than the maximum, replace the piston.
  7. 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 pushing 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, recheck the cylinder bore diameter for wear limits. If the bore diameter exceeds the service limit, the cylinder block must be replaced. Ring end gap: No. 1: 0.13–0.23 mm (0.0051–0.0091 in.) No. 2: 0.25–0.40 mm (0.0098–0.0157 in.) Oil ring: 0.2–0.7 mm (0.0079–0.0276 in.)
  8. Measure the piston pin diameter.

    Piston pin outside diameter: 17.997–18.000 mm (0.7085–0.7086 in.)

  9. Measure the clearance between the piston pin and the piston.

    Piston pin-to-piston clearance: 0.005–0.012 mm (0.0002–0.0005 in.)

  10. Check the difference between the piston pin outside diameter and the connecting rod small end inside diameter.

    Piston pin-to-connecting rod clearance: 0.005–0.014 mm (0.0002–0.0006 in.)

Piston Piston Rings Piston Pins

Installation

  1. Assemble the piston and connecting rod.
    1. Install the snap ring (A) on one side of the piston pin hole.
    2. Align the front mark of the piston (A) with the front mark of the connecting rod (B).
    3. Insert the piston pin (A) into the piston pin hole and the connecting rod small end hole.
    4. Install the snap ring (B) on the other side after installing the piston pin.
  2. Install the piston rings.
    1. Install the oil ring expander and 2 side rails 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. Install the connecting rod bearings.
    1. Align the bearing tab with the notch in the connecting rod and connecting rod cap.
    2. Install the bearings (A) on the connecting rod and connecting rod cap (B).
  4. Install the piston and connecting rod assembly.
    1. Install the piston ring compressor and make sure the bearing is securely in place. Then insert the piston into the cylinder and tap it in with the wooden handle of a hammer.
    2. Once the piston ring compressor is released, stop inserting and check the alignment of the connecting rod with the crankpin before inserting the piston into place.
    3. Apply engine oil to the threads of the bolts. Install the connecting rod caps with bearings and tighten the bolts.

      Tightening torque: 10.8–14.7 N·m + 88–92°

  5. Check the side clearance between the piston and the connecting rod.
  6. Assemble the remaining components in the reverse order of removal.

Test yourself

A quick Kia Picanto JA quiz: every answer comes with an explanation and a link to the manual page.