1500 Classic - Spark Plug Replacement 🔧

Nice job taking this on—totally doable at home with patience. Your 5.7L HEMI has 16 spark plugs (2 per cylinder), so plan a bit of time.

Quick questions before we start:

• 🔹 Are you working with basic hand tools only (ratchet set, screwdrivers), or do you also have a torque wrench?
• 🔹 Will you be using OEM-style plugs (NGK or Champion) or are you still choosing plugs?

I’ll assume basic tools and OEM-style plugs; if that’s wrong, tell me and I’ll adjust.

Tools & Parts Needed 🧰

• 🔹 New spark plugs (16 total)
  • Use plugs specified for the 5.7L HEMI (OEM-equivalent NGK or Champion).
  • They come pre-gapped usually, but we’ll still check the gap.
• 🔹 3/8" drive ratchet – basic handle that turns sockets.
• 🔹 Spark plug socket, 5/8" – special socket with rubber insert or magnet to hold the plug.
• 🔹 Socket extensions
  • 3" and 6" extensions will make life easier.
• 🔹 10 mm socket – for ignition coil bolts.
• 🔹 Torque wrench (3/8" drive) – tool that tightens bolts to a specific force.
• 🔹 Feeler gauge – thin metal blades used to measure spark plug gap.
• 🔹 Dielectric grease – non-conductive grease for inside coil boots to prevent moisture.
• 🔹 Anti-seize (optional, very small amount) – prevents threads from sticking; many modern plugs do not require it if they are nickel-plated.
• 🔹 Compressed air or a clean brush – to clean around plug holes.
• 🔹 Gloves and safety glasses – protect your hands and eyes.

Important Specs 📏

• 🔹 Number of plugs: 16 (2 per cylinder).
• 🔹 Spark plug gap (5.7L HEMI, 2020): typically around 0.043" (1.1 mm).
  • Confirm on the plug box or under-hood emissions label; use that value if different.
• 🔹 Spark plug torque: about 13–15 ft-lb (18–20 N·m) for tapered-seat plugs in aluminum heads.
• 🔹 Ignition coil bolt torque: about 80 in-lb (9 N·m).

Safety & Prep ⚠️

• 🔹 Engine cool – let the engine cool completely; aluminum heads can be damaged if plugs are removed hot.
• 🔹 Battery safety – turn ignition OFF and remove the key; you can disconnect the negative battery cable for extra safety.
• 🔹 Work one cylinder at a time – this avoids mixing up connectors and coils.

Accessing the Spark Plugs 🧱

Your 5.7L HEMI has coil-on-plug ignition. Each cylinder has a coil pack with two plug boots going down to two plugs.

1. Open the hood and locate the engine cover (if equipped).
   • Lift the plastic engine cover straight up; it usually just pops off rubber grommets.
2. Identify the ignition coils on each side of the engine.
   • They are black rectangular units with an electrical connector and two rubber boots going down into the valve cover.
3. Plan your order
   • Start on one side (driver or passenger) and do one coil and its two plugs at a time.

Removing Ignition Coils 🔌

1. Unplug the coil electrical connector for the first coil.
   • Press the locking tab on the connector and pull it straight off. Do not pull on the wires.
2. Remove the coil retaining bolt with a 10 mm socket.
3. Gently twist and pull the coil up.
   • You’ll see two rubber boots; they may be snug. Twist slightly to break them loose, then pull straight up.
4. Inspect the boots
   • Look for oil, cracks, or heavy corrosion. Light dust is normal; oil means a valve cover leak.

Removing Old Spark Plugs 🧽

1. Clean around the plug holes with compressed air or a brush.
   • This prevents dirt from falling into the cylinder.
2. Install the spark plug socket (5/8") on an extension and ratchet.
3. Remove the first plug (front boot position).
   • Turn counterclockwise to loosen. Once loose, spin out by hand using the extension.
4. Remove the second plug (rear boot position) from the same coil location.
5. Inspect the old plugs
   • Light tan/gray = normal.
   • Oily, wet, or heavily worn = note which cylinder; could indicate other issues.

Preparing New Spark Plugs 🛠️

1. Check the gap with a feeler gauge.
   • Slide the correct blade (e.g., 0.043") between the center and ground electrode.
   • You should feel a slight drag. If too tight, gently bend the ground strap out; if too loose, bend it in.
2. Anti-seize (only if recommended)
   • Most modern plugs are coated and do not need anti-seize. If you use it, apply a very thin film on the threads only, avoiding the tip.
3. Optional: mark the plug
   • You can put a small paint mark on the insulator to track which cylinder it came from if you’re diagnosing, but for routine service it’s not needed.

Installing New Spark Plugs 🔩

1. Start each plug by hand
   • Place the new plug in the spark plug socket and extension.
   • Thread it into the head by hand only, turning clockwise.
   • If it doesn’t spin easily, back out and try again. Do not cross-thread.
2. Snug the plug with the ratchet once it’s fully seated by hand.
3. Torque the plug to about 13–15 ft-lb.
   • Use a torque wrench if you have one.
   • If you don’t: from just seated, turn about 1/4 turn more on a new plug with a tapered seat. Do not over-tighten.
4. Repeat for the second plug in that cylinder (same steps).

Reinstalling Coils & Boots 🔁

1. Apply a small dab of dielectric grease inside each coil boot.
   • This helps sealing and makes future removal easier.
2. Align the coil boots with both plugs and push straight down.
   • You should feel them “seat” onto the plugs.
3. Reinstall the coil bolt and tighten to about 80 in-lb (snug, not gorilla tight).
4. Reconnect the electrical connector until it clicks.
5. Repeat this process for each coil position until all 8 coils and 16 plugs are done.

Final Checks & First Start 🚀

1. Double-check all connectors
   • Every coil plugged in, every bolt installed, no tools left in the engine bay.
2. Reinstall the engine cover if removed.
3. Reconnect the battery negative cable if you disconnected it.
4. Start the engine
   • It should start smoothly and idle evenly.
   • If it misfires or the check engine light flashes, shut it off and re-check coil connectors and plug wires/boots.

Tips & Tricks 💡

• 🔹 Do one coil at a time so you never mix up connectors.
• 🔹 Use a magnetic pickup tool if a plug or bolt is dropped in a tight spot.
• 🔹 Take photos before you start so you can see how everything looked originally.

If you tell me whether you have a torque wrench and which plug brand you’re using, I can fine-tune the torque and gap info for your exact plugs.

HowToo makes it easy: below this answer you’ll see recommended spark plugs, dielectric grease, a spark plug socket, and a torque wrench you can order with fast shipping. You can add them to your cart directly from the parts section.