Safety Warning
DIY auto repair can cause serious injury, fire, or vehicle damage. These guides are for informational purposes only. Always follow OEM torque specs, wear PPE, and consult a certified mechanic if you are unsure. You are solely responsible for your safety.
2008 Kia Optima L4-2.4LFACTORY OEM SERVICE PROCEDURE
Piston Ring, Engine
Piston ring
Side clearance
No. 1 ring
Specification 0.03 - 0.07 mm (0.0012-0.0028 in)
Limit 0.1 mm (0.004 in)
No. 2 ring
Specification 0.03 - 0.07 mm (0.0012-0.0028 in)
Limit 0.1 mm (0.004 in)
Oil ring
Specification 0.06 - 0.15 mm (0.0024 - 0.0059 in)
Limit 0.2 mm (0.008 in)
End gap
No. 1 ring
Specification 0.15 - 0.30 mm (0.0059 - 0.0118 in)
Limit 0.6 mm (0.0236 in)
No. 2 ring
Specification 0.30 - 0.45 mm (0.0118 - 0.0177 in)
Limit 0.7 mm (0.0275 in)
Oil ring
Specification 0.20 - 0.70 mm (0.0078 - 0.0275 in)
Limit 0.8 mm (0.0315 in)
Side clearance
No. 1 ring
Specification 0.03 - 0.07 mm (0.0012-0.0028 in)
Limit 0.1 mm (0.004 in)
No. 2 ring
Specification 0.03 - 0.07 mm (0.0012-0.0028 in)
Limit 0.1 mm (0.004 in)
Oil ring
Specification 0.06 - 0.15 mm (0.0024 - 0.0059 in)
Limit 0.2 mm (0.008 in)
End gap
No. 1 ring
Specification 0.15 - 0.30 mm (0.0059 - 0.0118 in)
Limit 0.6 mm (0.0236 in)
No. 2 ring
Specification 0.30 - 0.45 mm (0.0118 - 0.0177 in)
Limit 0.7 mm (0.0275 in)
Oil ring
Specification 0.20 - 0.70 mm (0.0078 - 0.0275 in)
Limit 0.8 mm (0.0315 in)
Factory Service Tools
Use the Manual With the Right Hardware
Pair factory procedures with proven DIY tools so the instructions are easier to execute.
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When to See a Mechanic
Stop DIY work and contact a certified mechanic immediately if any of the following apply:
- • You smell fuel, burning insulation, or see smoke.
- • Brakes feel soft, pull hard to one side, or make grinding noises.
- • The engine overheats, stalls repeatedly, or misfires under load.
- • You are missing required tools, torque specs, or safe lifting equipment.
- • You are not confident in the next step or safety outcome.