Hyundai Kona: Cylinder Block / Piston and Connecting Rod Repair procedures

Hyundai Kona (OS) 2018-2025 Service Manual / Engine Mechanical System / Cylinder Block / Piston and Connecting Rod Repair procedures

Disassembly
  
•
Use fender covers to avoid damaging painted surfaces.
•
To avoid damaging the cylinder head, wait until the engine coolant temperature drops below normal temperature before removing it.
•
When handling a metal gasket, take care not to fold the gasket or damage the contact surface of the gasket.
•
To avoid damage, unplug the wiring connectors carefully while holding the connector portion.
  
•
To avoid damage, unplug the wiring connectors carefully while holding the connector portion.
•
Turn the crankshaft so that the No.1 piston is at TDC (Top dead center).
1.
Remove the engine assembly from the vehicle.
(Refer to Engine and Transaxle Assembly - "Engine and Transaxle Assembly")
2.
Remove the transaxle assembly from the engine assembly.
(Refer to DCT(Dual clutch Transmission) System - "DCT (Dual clutch Transmission)")
3.
Remove the external damper flywheel (A).
(Refer to Cylinder block - "External Damper Flywheel")
4.
Remove the rear oil seal.
(Refer to Cylinder Block - "Rear Oil Seal")
5.
Install the engine to engine stand for disassembly.
6.
Remove the intake manifold.
(Refer to Intake and Exhaust System - "Intake Manifold")
7.
Remove the exhaust manifold.
(Refer to Intake and Exhaust System - "Exhaust Manifold")
8.
Remove the timing chain.
(Refer to Timing System - "Timing Chain")
9.
Remove the cylinder head assembly.
(Refer to Cylinder Head Assembly - "Cylinder Head")
10.
Remove the oil pan and oil screen.
(Refer to Lubrication System - "Oil Pan")
11.
Remove the oil cooler.
(Refer to Lubrication System - "Oil Cooler")
12.
Remove the ladder frame (A).
13.
Check the connecting rod side clearance.
14.
Check the connecting rod bearing cap oil clearance.
15.
Remove the piston and connecting rod assembly.
(1)
Using a ridge reamer, remove all the carbon from the top of the cylinder.
(2)
Remove the connecting rod bearing caps (A).

  
•
Mark the connecting rod and caps to be able to reassemble in the original position and direction.
(3)
Push the piston and connecting rod assembly with upper bearing through the top of the cylinder block.
  
•
Keep the connecting rod and caps with the bearings assembled together.
•
Arrange the piston and connecting rod assemblies in the correct order.
•
Mark the piston and connecting rod assembly to be able to reassemble in the original position.
16.
Check fit between piston and piston pin.
17.
Disassemble the piston rings.
(1)
Using a piston ring expender, remove the two compression rings.
(2)
Remove the side rail and coil spring.
  
•
Arrange the piston rings in the correct order.
18.
Remove the piston and connecting rod.
Inspection
Connecting Rod
1.
Check the side clearance between piston and connecting rod.
Using filler gauge, measure the side clearance while moving the connecting rod back and forth.
Side clearance
Standard : 0.10 - 0.25 mm (0.0039 - 0.0098 in)
Maximum : 0.35 mm (0.0138 in)

•
If out-of-tolerance, install a new connecting rod.
•
If still out-of-tolerance after connecting rod replacement, replace the crankshaft.
2.
Check the connecting rod bearing oil clearance.
(1)
Check the match marks on the connecting rod and cap are aligned to ensure correct reassembly.
(2)
Remove the 2 connecting rod cap bolts.
(3)
Remove the connecting rod cap and lower bearing.
(4)
Clean the crankshaft pin journal and bearing.
(5)
Place a plastigage across the crankshaft pin journal.
(6)
Reinstall the lower bearing and connecting rod cap, and tighten the bolts.
Tightening torque :
17.7 - 21.6 N.m (1.8 - 2.2 kgf.m, 13.0 - 15.9 lb-ft) + 88°-92°
  
•
Do not turn the crankshaft.
•
Do not reuse the connection rod cap bolts.
(7)
Remove the connecting rod cap.
(8)
Measure the plastigage at its widest point.
Standard oil clearance :
0.030 - 0.050 mm (0.0012 - 0.0020 in)

(9)
If the measurement from the plastigage is too wide or too narrow, remove the upper and lower bearing and then install a new bearings with the same color mark.
Recheck the oil clearance.
  
•
Do not file, shim on scrape the bearings or the caps to adjust clearance.
(10)
If the plastigage shows the clearance is still incorrect, try the next larger or smaller bearing. Recheck the oil clearance.
  
•
If the proper clearance cannot be obtained by using the appropriate larger or smaller bearings, replace the crankshaft and start over.
  
•
If the marks are indecipherable because of an accumulation of dirt and dust, do not scrub them with a wire brush or scraper. Clean them only with solvent or detergent.
Connecting Rod Identification Mark

Connecting Rod Specifications
Class
Mark
Inside Diameter
0
 A, 0
 45.000 - 45.006 mm
(1.7717 - 1.7719 in)
1
 B, 00
 45.006 - 45.012 mm
(1.7719 - 1.7721 in)
2
 C, 000
 45.012 - 45.018 mm
(1.7721 - 1.7724 in)

Crankshaft Pin Identification Mark

Crankshaft Specifications
Mark
Outside Diameter Of Pin
1
 41.966 - 41.972 mm
(1.6522 - 1.6524 in)
2
 41.960 - 41.966 mm
(1.6520 - 1.6522 in)
3
 41.954 - 41.960 mm
(1.6517 - 1.6520 in)

Connecting Rod Bearing Identification Mark

Connecting Rod Bearing Specifications
Class
Mark
Thickness Of Bearing
A
 Light Blue
 1.514 - 1.517 mm
(0.0596 - 0.0597 in)
B
 Black
 1.511 - 1.514 mm
(0.0595 - 0.0596 in)
C
 White
 1.508 - 1.511 mm
(0.0594 - 0.0595 in)
D
 Light Green
 1.505 - 1.508 mm
(0.0593 - 0.0594 in)
E
 Pink
 1.502 - 1.505 mm
(0.0591 - 0.0593 in)

(11)
Use the bearing selection table below to select a suitable connecting rod bearing.
Selection Chart For Connecting Rod Bearings
Assembling Classification Of Bearing
Connecting Rod Identification Mark
A, 0
B, 00
C, 000
Crankshaft Pin Journal Indentification Mark
 1
 E
(pink)
 D
(Light Green)
 C
(White)
2
 D
(Light Green)
 C
(White)
 B
(Black)
3
 C
(White)
 B
(Black)
 A
(Light Blue)

3.
Check the connecting rod.
(1)
When reinstalling, make sure that cylinder numbers put on the connecting rod and cap at disassembly match. When a new connecting rod is installed, make sure that the notches for holding the bearing in place are on the same side.
(2)
Replace the connecting rod if it is damaged on the thrust faces at either end. Also if step wear or a severely rough surface of the inside diameter of the small end is apparent, the rod must be replaced as well.
(3)
Using a connecting rod aligning tool, check the rod for bend and twist. If the measured value is close to the repair limit, correct the rod by a press. Any connecting rod that has been severely bent or distorted should be replaced.
Allowable bend of connecting rod :
0.05 mm (0.0020 in) or less / 100 mm (3.94 in)
Allowable twist of connecting rod :
0.1 mm (0.0039 in ) or less / 100 mm (3.94 in)
  
•
When the connecting rods installed without bearings, there should be no difference on side surface.
Piston
1.
Clean the piston.
(1)
Using a gasket scraper, remove the carbon from the piston top.
(2)
Using a groove cleaning tool or broken ring, clean the piston ring grooves.
(3)
Using solvent and a brush, thoroughly clean the piston.
  
•
Do not use a wire brush.
2.
Check the piston-to-cylinder clearance by calculating the difference between the cylinder bore inner diameter and the piston outer diameter.
Piston-to-cylinder clearance :
0.02 - 0.04 mm (0.0008 - 0.0016 in)
(1)
Using a cylinder bore gauge, measure the cylinder bore diameter at position in the thrust and axial direction.
Cylinder bore diameter :
77.00 - 77.03 mm (3.0315 - 3.0327 in)

(2)
Measure the piston outside diameter at 12.0 mm (0.4724 in) from top land of the piston.
Piston outside diameter :
76.97 - 77.00 mm (3.0303 - 3.0315 in)

3.
Select the piston matching with cylinder bore class (match classification mark).
Piston-to-cylinder clearance :
0.02 - 0.04 mm (0.0008 - 0.0016 in)
(1)
Check the cylinder bore size mark on the side of the cylinder block.

Discrimination Of Cylinder Bore Size
Mark
Cylinder bore inner diameter
A
 77.000 - 77.010 mm
(3.0315 - 3.0319 in)
B
 77.010 - 77.020 mm
(3.0319 - 3.0323 in)
C
 77.020 - 77.030 mm
(3.0323 - 3.0327 in)

(2)
Check the piston size mark on the piston top face.

A : Piston diameter grade (A, B, C)
T : T-GDI Engine
6: Displacement (1.6L)
E : Type (Fuel efficiency)
Piston Outer Diameter Difference
Mark
Piston outer diameter
A
 76.97 - 76.98 mm
(3.0303 - 3.0307 in)
B
 76.98 - 76.99 mm
(3.0307 - 3.0311 in)
C
 76.99 - 77.00 mm
(3.0311 - 3.0315 in)

Piston Ring
1.
Inspect the piston ring side clearance.
Using a feeler gauge, measure the clearance between new piston ring and the wall of ring groove.
Piston ring side clearance
No.1 ring : 0.04 - 0.08 mm (0.0015 - 0.0031 in)
No.2 ring : 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 ring : 0.1 mm (0.0039 in)
No.2 ring : 0.1 mm ( 0.0039 in)
Oil ring : 0.2 mm (0.0079 in)

If the clearance is greater than maximum, replace the piston.
2.
Inspect the piston ring end gap.
To measure the piston ring end gap, insert a piston ring into the cylinder bore. Position the ring at right angles to the cylinder wall by gently pressing it down with a piston. Measure the gap with a feeler gauge.
Piston ring end gap
[Standard]
No.1 ring : 0.14 - 0.24 mm (0.0079 - 0.0094 in)
No.2 ring : 0.30 - 0.45 mm (0.0118 - 0.0177 in)
Oil ring : 0.20 - 0.40 mm (0.0079 - 0.0157 in)
[Limit]
No.1 ring : 0.3 mm (0.0118 in)
No.2 ring : 0.5 mm (0.0197 in)
Oil ring : 0.8 mm (0.0315 in)

Piston pins
1.
Measure the outer diameter of piston pin
Piston pin diameter :
19.997 - 20.000 mm (0.7873 - 0.7874 in)

2.
Measure the piston pin-to-piston clearance.
Piston pin-to-piston clearance :
0.004 - 0.012 mm (0.0002 - 0.0005 in)
3.
Check the difference between the piston pin outer diameter and the connecting rod small end inner diameter.
Piston pin-to-connecting rod clearance :
0.005 - 0.014 mm (0.0002 - 0.0006 in)
Reassembly
  
•
Thoroughly clean all parts to 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.
Assemble the piston and connecting rod.
(1)
Install the snap ring (A) on one side of the piston pin hole.
(2)
Align the piston front mark and the connecting rod front mark.
(3)
Insert the piston pin (B) into the piston pin hole and the small end bore of connecting rod.
(4)
Install the snap ring (C) on the other side after inserting the piston pin
(5)
The piston front mark (A) and the connecting rod front mark (B) must face the timing chain side of the engine.

  
•
Before inserting the piston pin, apply sufficient engine oil on the piston’s outer surface, piston hole’s inner surface and connecting rod’s small-end bore.
•
When inserting, use caution not to damage or scratch the connecting rods’ small-end hole, piston’s pin hole and piston pin.
•
Mount the snap ring surely so that the snap ring contacts the overall groove of the piston’s pin hole.
•
Assemble so that the cut surface of the snap ring is located within the upper 45° range.
•
Do not reuse the snap ring that is unstably fitted.
2.
Install the piston rings.
(1)
Install the oil ring coil spring and the side rail by hand.
(2)
Using a piston ring expander, install the 2 compression rings with the code mark facing upward.
(3)
Position the piston rings so that the ring ends are as shown.
3.
Install the connecting rod bearings.
(1)
Align the bearing (A) claw with the groove of the connecting rod or connecting rod cap (B).
(2)
Install the bearings (A) in the connecting rod and connecting rod cap (B).
4.
Install the piston and connecting rod assembly .
  
•
Before installing the piston, apply a sufficient amount of engine oil to the ring grooves and cylinder bores
(1)
Press the piston rings with a ring compressor and check that the rings are securely in place. Then insert the piston into the cylinder bore, and tap it in using the wooden handle of a hammer.

(2)
Stop after the ring compressor pops free, and check the connecting rod-to-crank journal alignment before pushing the piston into place.
(3)
Install the rod caps with bearings, and tighten the bolts.
Tightening torque :
17.7 - 21.8 N.m (1.8 - 2.2 kgf.m, 13.0 - 15.9 lb-ft) + 88 - 92°
  
•
Always use new connecting rod cap bolts.
5.
Check the side clearance between piston and connecting rod.
6.
Install the ladder frame.
(1)
Clean the ladder frame.
To be removed harmful foreign matters, oil, dust and moisture on surface that sealed by sealant.
(2)
Apply the sealant on the ladder frame.
Bead width : 2.5 - 3.5 mm (0.0984 - 0.1378 in)

  
•
Apply the sealant, (THREE-BOND 1217H or LOCTITE 5900H) on the ladder frame rail portion and install it with in five minutes.
•
If when sealant is applied to cylinder block bottom position, sealant position to be same with positon that is applied to ladder frame rail position.
•
Apply sealant along the inner line of the bolt holes.
(3)
Install the ladder frame (A).
Tightening torque :
18.6 - 23.5 N.m (1.9 - 2.4 kgf.m, 13.7 - 17.4 lb-ft)

7.
Assemble the other parts in the reverse order of disassembly.
Piston and Connecting Rod Components and components location
Components 1. Piston ring 2. Piston 3. Connecting rod 4. Connecting rod upper bearing 5. Connecting rod lower bearing 6. Connecting rod bearing ...

Crankshaft Components and components location
Components 1. Crankshaft 2. Crankshaft upper bearing 3. Crankshaft lower bearing 4. Thrust bearing 5. Main bearing cap 6. Crankshaft sproket 7. ...

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