Complete removal and replacement of all four pistons and connecting rod assemblies, requiring engine disassembly from below with crankshaft exposure.

Warnings

Tools required

Parts

• Complete piston and ring set (includes 4 pistons, pins, clips, and rings) × 1 — Use OEM specification
• Connecting rod bearing set (standard size) × 1 — Verify size with measurements
• Cylinder head gasket × 1 — Use OEM specification
• Valve cover gasket × 1 — Use OEM specification
• Oil pan gasket × 1 — Use OEM specification
• Front crankshaft seal × 1 — Use OEM specification
• Rear crankshaft seal × 1 — Use OEM specification
• Oil filter × 1 — Use OEM specification
• Oil drain plug crush washer × 1 — Use OEM specification
• Timing chain components (if replacing) × 1 — Recommended during this service
• Engine assembly lube/moly paste × 1 — Use manufacturer approved lubricant
• RTV silicone sealant × 1 — High-temp gasket maker

Fluids

• Kia Genuine 5W-20 engine oil — 4.5 qt
• Hyundai/Kia Long Life Coolant (Green) — 7.5 qt

Preparation

1. Disconnect negative battery cable and secure away from terminal
2. Drain engine coolant completely into appropriate container
3. Drain engine oil completely and remove oil filter
4. Remove engine cover and air intake assembly
5. Remove accessory drive belt(s)
6. Raise and securely support vehicle on jack stands at manufacturer lift points
7. Remove front wheels and splash shields for access
8. Support engine from above using engine hoist or support fixture attached to lifting eyes
9. Label and photograph all electrical connections, vacuum lines, and hose routing for reassembly reference
10. Have clean workspace prepared for component inspection and measurement

Procedure

1. 1

   Remove cylinder head assembly
   Disconnect all electrical connectors, coolant hoses, fuel lines, and vacuum lines from cylinder head. Remove exhaust manifold and intake manifold assemblies. Remove timing chain cover, timing chain, and camshafts following manufacturer procedure. Remove cylinder head bolts in reverse of tightening sequence (outside to inside pattern). Carefully lift cylinder head from block and place on clean surface with combustion chambers facing up. Inspect head gasket surface for warping.
2. 2

   Remove oil pan and pickup tube
   Support front subframe and remove engine mount bolts if necessary for clearance. Remove oil pan bolts in crisscross pattern and carefully separate oil pan from block using plastic pry tool at designated pry points. Remove oil pump pickup tube mounting bolt and remove tube assembly. Clean all gasket surfaces thoroughly.
   Torque spec

   Oil Pan Bolts12 Nm (9 lb-ft)

   Oil Pump Pickup Tube12 Nm (9 lb-ft)
3. 3

   Remove ridge from cylinder bores
   Rotate crankshaft to bring each piston to bottom dead center (BDC). Using a ridge reamer, carefully remove the wear ridge at the top of each cylinder bore. This prevents piston ring damage during removal. Clean all cutting debris from cylinders with lint-free cloth and light oil. Do NOT allow debris to enter crankcase.
   ⚠Ridge must be completely removed to prevent piston ring breakage during removal. However, do not cut into unworn cylinder surface below ridge.
4. 4

   Mark and remove connecting rod assemblies
   Using permanent marker or stamp, mark each connecting rod and cap with cylinder number (1-4) and orientation (direction facing front of engine). Rotate crankshaft to bring cylinder #1 to bottom dead center. Remove connecting rod cap bolts from cylinder #1. Carefully remove rod cap and bearing insert (keep with cap). Push piston and rod assembly up and out through top of cylinder bore. Install rod cap back onto rod loosely to keep sets together. Repeat for cylinders 2, 3, and 4. Place assemblies on clean work surface in order.
   ⚠Do not allow connecting rods to strike crankshaft journals during removal as this can damage the bearing surface. Use rod bolt protectors or wrap bolts with tape.
   Torque spec

   Connecting Rod Bolts45 Nm (33 lb-ft)
5. 5

   Disassemble piston and rod assemblies
   Using piston pin removal tool or hydraulic press, carefully press out piston pins and separate pistons from connecting rods. Keep all components organized by cylinder number. Remove piston rings using ring removal tool, taking care not to damage ring grooves. Inspect connecting rods for bends, twists, or damage. Inspect rod bearings for unusual wear patterns which may indicate crankshaft or oiling problems.
   ℹ️Piston pin may require heat application to piston (not rod) if interference fit. Never exceed 150°F when heating aluminum pistons.
6. 6

   Measure and inspect cylinder bores
   Using cylinder bore gauge, measure each cylinder at top, middle, and bottom positions in both parallel and perpendicular orientations to crankshaft. Record all measurements. Calculate taper (difference between top and bottom) and out-of-round (difference between perpendicular measurements at same height). Compare to Kia specifications: maximum taper 0.0079 inches (0.20mm), maximum out-of-round 0.0020 inches (0.05mm). If within limits and surface finish is good, deglaze cylinders with ball hone. If out of specification, cylinders must be bored and honed to next oversize.
   ⚠Installing standard size pistons in worn cylinders will result in excessive oil consumption, blow-by, and premature engine failure. Proper measurement is critical.
7. 7

   Prepare new pistons and measure ring gaps
   Clean new pistons thoroughly. Install pistons onto connecting rods using new piston pins and clips, ensuring directional arrows on piston crowns face front of engine and rod bearing tangs align properly. Secure with new retaining clips. For each cylinder, insert each piston ring (individually) into its corresponding cylinder bore and push down 0.5 inches with piston crown to square ring in bore. Measure end gap with feeler gauge. Top ring should be 0.0079-0.0138 inches, second ring 0.0177-0.0236 inches, oil ring 0.0079-0.0276 inches. File ring ends if gap is too tight.
   ⚠Piston pin clips must be fully seated in grooves. Improper installation can allow clip to fall out, causing catastrophic engine damage.
   ⚠Ring end gap must never be less than minimum specification or rings will butt together when heated, breaking rings and scoring cylinder walls.
8. 8

   Install piston rings
   Using piston ring expander tool, install oil control ring expander first into bottom groove. Install oil control ring rails above and below expander, ensuring ends are positioned 180° apart. Install second compression ring with marking facing up into middle groove. Install top compression ring with marking facing up into top groove. Stagger all ring end gaps approximately 120° apart, avoiding piston pin axis and thrust direction. Clean ring grooves and verify rings move freely in grooves.
   ⚠Ring orientation is critical. Marking or text on ring must face UP toward piston crown. Inverted rings will cause immediate oil consumption and loss of compression.
9. 9

   Install connecting rod bearings and check clearances
   Wipe crankshaft rod journals clean with lint-free cloth. Install bearing inserts into connecting rods and caps, ensuring tang locks into notch. Apply light coat of clean engine oil to bearings. Place strip of Plastigage across rod journal. Install rod and piston assembly onto journal (do not rotate crankshaft). Install rod cap in correct orientation and torque cap bolts to 45 Nm (33 lb-ft) ONLY - do not apply angle yet. Remove cap and measure Plastigage width. Clearance should be 0.0007-0.0014 inches. If incorrect, determine cause (wrong bearings, journal size, dirt). Remove Plastigage completely before final assembly.
   ⚠Do not rotate crankshaft with Plastigage in place or measurement will be invalid.
10. 10

    Final installation of piston and rod assemblies
    Liberally coat piston rings, pistons, and cylinder bores with engine assembly lube. Coat rod bearings with clean engine oil. Starting with cylinder #1, compress piston rings using ring compressor tool and carefully tap piston into bore with wooden hammer handle, ensuring directional arrow faces front of engine. Guide connecting rod onto crankshaft journal, protecting journal with rod bolt protectors. Install rod bearing cap in correct orientation with match marks aligned. Install NEW connecting rod bolts hand-tight. Repeat for all four cylinders. Once all assemblies are installed, torque each rod bolt to 45 Nm (33 lb-ft), then rotate an additional 90 degrees using torque angle gauge. Verify crankshaft rotates smoothly by hand with no binding.
    ⚠️Connecting rod bolts are torque-to-yield and must be NEW. Using old bolts will result in bolt failure and catastrophic engine destruction.
    ⚠Ring compressor must be tight and square to cylinder bore. If piston does not slide in easily, STOP and reposition compressor. Forcing piston will break rings.
    Torque spec

    Connecting Rod Bolts45 Nm (33 lb-ft)
11. 11

    Install oil pump pickup tube and oil pan
    Install new oil pump pickup tube O-ring seal and position tube into oil pump. Torque pickup tube mounting bolt to 12 Nm (9 lb-ft). Clean oil pan and block mating surfaces thoroughly with gasket scraper and solvent. Install new oil pan gasket or apply 2-3mm bead of RTV silicone to oil pan sealing surface. Position oil pan and install bolts finger-tight. Torque oil pan bolts in crisscross pattern from center outward to 12 Nm (9 lb-ft). If RTV was used, wait 30 minutes before filling with oil.
    Torque spec

    Oil Pump Pickup Tube12 Nm (9 lb-ft)

    Oil Pan Bolts12 Nm (9 lb-ft)
12. 12

    Install cylinder head assembly
    Verify block deck surface and cylinder head surface are completely clean and flat. Install new cylinder head gasket with markings facing up. Carefully lower cylinder head onto block, aligning dowel pins. Install NEW cylinder head bolts with light oil on threads. Torque bolts in proper sequence (center outward spiral pattern) to 65 Nm (48 lb-ft), then rotate each bolt an additional 90 degrees, followed by final 45 degrees in same sequence. Install timing chain, camshafts, and timing cover following manufacturer specifications and timing marks.
    ⚠️Cylinder head bolts are torque-to-yield and must be replaced. Reusing old bolts can result in head gasket failure and engine damage.
    ⚠Tightening sequence and angle rotation must be followed exactly. Improper sequence will distort head and cause gasket failure.
    Torque spec

    Cylinder Head Bolts65 Nm (48 lb-ft)
13. 13

    Complete engine reassembly
    Install valve cover with new gasket. Reconnect all electrical connectors, coolant hoses, vacuum lines, fuel lines, intake and exhaust manifolds according to reference photos. Reinstall accessory drive belt(s). Install new oil filter and install oil drain plug with new crush washer, torquing to 35 Nm (26 lb-ft). Lower vehicle and remove engine support. Reconnect battery.
    Torque spec

    Oil Drain Plug35 Nm (26 lb-ft)
14. 14

    Fill fluids and perform initial start
    Fill engine with 4.5 quarts of Kia Genuine 5W-20 engine oil. Fill cooling system with 7.5 quarts of Hyundai/Kia Long Life Coolant (Green). Double-check all connections, bolts, and hoses. Turn ignition to ON position (do not start) and check for oil pressure warning light. Crank engine for 10-15 seconds without starting to build oil pressure. Start engine and immediately verify oil pressure. Listen for abnormal noises. Allow engine to warm to operating temperature while monitoring for leaks, unusual sounds, or warning lights. Bleed cooling system of air pockets.
    ⚠️If oil pressure is not achieved within 10 seconds of starting, IMMEDIATELY shut down engine and investigate. Running without oil pressure will destroy the fresh engine assembly.
    ⚠Initial startup should be closely monitored. Any knocking, ticking, or unusual sounds may indicate assembly error and should be investigated before continuing operation.

Reassembly

1. Torque all fasteners to specified values using torque wrench and angle gauge for TTY bolts
2. Use all new gaskets, seals, and torque-to-yield fasteners - never reuse
3. Apply engine assembly lube to all bearing surfaces, piston rings, and cylinder bores during assembly
4. Verify proper orientation of all components: pistons face forward, connecting rods align correctly, timing marks properly positioned
5. Allow RTV silicone to cure for recommended time before filling with oil if used
6. Prime oil system before initial startup by cranking engine without fuel/spark for 10-15 seconds

Verification

• Verify engine starts readily and achieves immediate oil pressure (light goes out within 3-5 seconds)
• Listen for abnormal noises including knocking, ticking, or rattling during warm-up period
• Check for oil, coolant, and fuel leaks around all disturbed connections and gaskets
• Monitor engine temperature gauge for normal operating temperature and proper thermostat function
• Perform compression test on all cylinders after initial warm-up - should be within 10% of each other and meet specifications (typically 170-185 psi)
• Check for excessive blow-by at oil filler cap or PCV valve indicating poor ring seal
• After 20 minutes of operation at varying RPM, shut down and recheck oil level, coolant level, and inspect for any new leaks
• Test drive vehicle and verify normal power delivery, smooth operation, and no warning lights
• Schedule oil and filter change at 500 miles to remove break-in debris
• Recheck cylinder head bolt torque after engine reaches full operating temperature (if manufacturer specifies)

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