2017 Dodge Challenger Spark Plug Replacement — 3.6L Pentastar & 5.7L HEMI

I've done this job on both versions of the 2017 Challenger, and the two engines could not be more different to work on. The 3.6L Pentastar V6 is surprisingly accessible and takes about 45 minutes. The 5.7L HEMI V8 is a bigger job — especially because the HEMI runs two spark plugs per cylinder, meaning you're replacing 16 plugs total, not 8. Here's exactly how I do both.

Which Engine Do You Have?

Pop the hood and look at the engine cover:

• 3.6L Pentastar V6 — Most base and SXT Challengers. "3.6 VVT" on the cover.
• 5.7L HEMI V8 — R/T trims and up. "5.7L HEMI" badging on the fenders and cover.

The 6.4L SRT is a separate procedure not covered here.

Parts and Specs

3.6L Pentastar V6 (6 plugs)

Item	Spec
Spark plug	NGK 96767 (ILKAR7L11)
Gap	Pre-gapped, do not adjust
Torque	13 ft-lb (18 Nm)
Interval	60,000 miles (iridium)
Thread size	M12 × 1.25

Alternatives: Champion 9802 (OEM equivalent), Mopar SP149316AB

5.7L HEMI V8 (16 plugs — 2 per cylinder)

Item	Spec
Spark plug	Champion RC12YC4 or NGK BKR5EYA
Gap	0.040" (1.0 mm)
Torque	13 ft-lb (18 Nm)
Interval	30,000 miles (copper)
Thread size	M14 × 1.25

The HEMI's dual-plug design is why the plug count doubles. Each cylinder fires two plugs on alternating cycles — buy 16 plugs before you start, not 8.

Tools Needed

• 5/8" spark plug socket (for HEMI)
• 9/16" spark plug socket (for Pentastar)
• 3" and 6" extensions
• Torque wrench
• Spark plug gap tool (HEMI only)
• Dielectric grease
• Anti-seize (optional — many recommend dry installation with iridium plugs; use your judgment)

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3.6L Pentastar V6 — Step-by-Step

1. Let the engine cool completely. Aluminum heads strip easily if you torque plugs in a warm engine.

2. Remove the plastic engine cover — it lifts straight off two locating pins on most Challenger V6s.

3. The Pentastar has 3 coil-on-plug (COP) assemblies per bank (6 total). Each COP sits directly over one plug. Unplug the electrical connector on each COP — press the tab and pull straight back.

4. Remove the single 10mm bolt holding each COP to the valve cover.

5. Pull each COP straight up and out. If it's stuck, twist slightly while pulling — don't pry against the valve cover.

6. Use the 9/16" plug socket with a 6" extension. Break each plug loose counterclockwise. Once loose, remove by hand to avoid dropping debris into the cylinder.

7. Blow out each plug well with compressed air before removing the plug. Any debris around the plug hole falls straight into the cylinder if you skip this.

8. Install new NGK plugs by hand until snug, then torque to 13 ft-lb. These are pre-gapped iridium plugs — do not adjust the gap.

9. Apply a thin film of dielectric grease inside the COP boot. Reinstall each COP and snug the 10mm bolt.

10. Reconnect all 6 electrical connectors. Reinstall the engine cover.

11. Start the engine. It may stumble for a few seconds while oil film clears the new plug tips — this is normal.

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5.7L HEMI V8 — Step-by-Step

The HEMI has 8 primary plugs on top and 8 secondary plugs on the side/bottom of each cylinder head. The top plugs are straightforward; the secondary plugs require more patience.

Top Plugs (8 total)

1. Remove the engine cover — the 5.7L cover clips to 4 studs.

2. Disconnect the 8 top COP units (one per cylinder, same process as the V6 above). Remove the 10mm hold-down bolt on each.

3. Use the 5/8" socket with a 3" extension. Break loose and remove all 8 top plugs. Remember: compressed air in the well before removing.

4. Install new plugs. Gap to 0.040" before installation — Champion RC12YC4 and NGK BKR5EYA need to be checked even if listed as "pre-gapped."

5. Hand-thread each plug to avoid cross-threading, then torque to 13 ft-lb.

6. Reinstall the 8 COPs and reconnect their connectors.

Secondary (Side) Plugs (8 total)

7. The secondary plugs are on the outboard face of each cylinder bank, accessed from beneath the intake runners. You'll need a longer 12" extension to reach them comfortably.

8. There are no COPs on these plugs — they connect to a coil pack via individual spark plug wires. Grasp each wire at the boot (not the wire) and twist/pull to remove.

9. Use the 5/8" socket + 12" extension. These plugs can be tighter — use a breaker bar to break them loose if needed.

10. Remove, gap new plugs to 0.040", and install hand-tight before torquing to 13 ft-lb.

11. Push each plug wire back onto its plug until you feel/hear a click.

12. Reinstall the engine cover and start the engine.

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Common Mistakes

1. Buying 8 plugs for the HEMI. Every HEMI beginner does this. Buy 16. Count your cylinders, double it.

2. Skipping the compressed air step. Carbon debris in a cylinder is a headache you don't need. Takes 10 seconds per hole.

3. Over-torquing iridium plugs. 13 ft-lb on the Pentastar. The electrode on an iridium plug is fragile — over-torquing changes the gap and can fracture the tip.

4. Not gapping HEMI plugs. Champion and NGK ship the RC12YC at roughly 0.040" but they drift in shipping. Check every one.

5. Reinstalling COPs without dielectric grease. The boot will stick to the plug over time and make your next plug change miserable. A pea-sized dab inside the boot prevents it.

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Cost Comparison: DIY vs. Dealer

	DIY	Dodge Dealer
Plugs (V6 × 6)	~$30	Included
Plugs (HEMI × 16)	~$45	Included
Labor	$0	$150–$350
Total (V6)	~$30	$180–$280
Total (HEMI)	~$45	$200–$395

For more Dodge Challenger spark plug context, the 2016 Dodge Challenger spark plug replacement guide covers the same Pentastar procedure with additional tips on the pre-'17 coil bracket differences. If you're also servicing a Dodge Charger, the 2017 Dodge Charger spark plug replacement shares the same engine specs.

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