Spark Plug Replacement — JL Wrangler 3.6L Pentastar and 2.0T

Difficulty 2/51–2.5 hrs$40–1002018-2024

The 3.6L Pentastar spark plugs are due at 30,000 miles — Mopar specifies NGK plugs and a specific torque. The 2.0T uses iridium plugs rated to 60,000 miles. Both are DIY-accessible with a quality socket set and about 90 minutes.

# Spark Plug Replacement — JL Wrangler 3.6L Pentastar and 2.0T

Jeep recommends 30,000-mile spark plug intervals on the 3.6L Pentastar. The 2.0T eTorque is rated to 60,000 miles on its iridium plugs. Real-world experience in the Jeep community suggests the 30,000-mile interval holds up — the Pentastar is sensitive to worn plugs in a way the 2.0T is less so.

Both engines are accessible with standard tools. The 3.6L's plugs are split across both valve covers — three per side, accessed from above. The 2.0T has four in a row across the top of the engine and is slightly more accessible.

**3.6L Pentastar:**

**2.0T Turbo:**

**3.6L (both banks, same process)**

1. Let the engine cool completely. Remove the engine cover (if equipped) by pulling straight up — it clips on.

2. Disconnect the ignition coil connector on each cylinder before removing the coil. The coil is held by a single 10mm bolt.

3. Remove the coil. Blow or vacuum any debris out of the plug well before breaking the plug loose — debris in the combustion chamber is a bad day.

4. Use the plug socket with an extension to loosen the plug — counterclockwise. It will be 18–20mm deep in the well.

5. Remove the old plug. Inspect: the electrode gap should be 0.044" new; worn plugs will show a wider gap, rounded electrode, or carbon deposits.

6. Check the new plug gap (pre-gapped from NGK but verify): 0.044" for the Pentastar.

7. Thread the new plug in by hand until snug — use a rubber hose on the plug body to avoid cross-threading. Torque to 13 ft-lb.

8. Reinstall the coil and torque the coil bolt to 89 in-lb (a little under 8 ft-lb).

9. Reconnect the coil connector — it will click.

10. Repeat for remaining 5 cylinders.

**2.0T (4 plugs in a row)**

1. Same prep: engine cool, remove coils (10mm bolts), clean plug wells.

2. Plug gap for the 2.0T: 0.028" — verify each plug before install.

3. Torque to 20 ft-lb (higher than the Pentastar — the 2.0T's aluminum head spec is different).

4. Reinstall coils to 89 in-lb.

Labor at a shop runs $150–$250 depending on location. This is a straightforward DIY with a torque wrench — the only part that slows most people down is the rear bank plugs on the 3.6L, which require a 6" extension and some patience.

Tools required

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Written and maintained by an AZ wheeler and driveway wrencher. Always cross-reference your factory service manual — modifications affect vehicle safety and warranty. Work at your own risk.