🔧 1500 - Spark Plug Replacement

Your 1500 with the 5.7L HEMI uses 16 spark plugs, two per cylinder. Replacing them restores strong ignition, smoother idle, better throttle response, and helps prevent misfires.

Difficulty Level: Intermediate | Estimated Time: 2.5-4 hours

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⚠️ Safety & Precautions

• ⚠️ Let the engine cool completely before starting. Hot aluminum cylinder heads can damage threads and burn your hands.
• ⚠️ Disconnect the negative battery cable before unplugging ignition coils.
• ⚠️ Work one cylinder at a time so the ignition coil connectors and boots do not get mixed up.
• ⚠️ Do not use anti-seize unless the spark plug manufacturer specifically says to. Many modern plugs are already coated.
• ⚠️ Always start spark plugs by hand to avoid cross-threading the aluminum cylinder head.

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🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 8mm socket
• 5/8-inch spark plug socket
• 3/8-inch drive ratchet
• 3/8-inch drive torque wrench
• 3-inch extension
• 6-inch extension
• 10-inch extension
• 3/8-inch universal joint adapter
• Needle-nose pliers
• Flat-blade screwdriver
• Spark plug gap gauge
• Compressed air blow gun
• Dielectric grease
• Fender cover
• Mechanic gloves
• Safety glasses

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Spark plugs - Qty: 16
• Ignition coil boots - Qty: 16 if worn, cracked, oil-soaked, or swollen
• Throttle body gasket - Qty: 1 if throttle body removal is needed for access
• Intake resonator seal - Qty: 1 if damaged during removal

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📋 Before You Begin

• Park your 1500 on level ground, shift to Park, and set the parking brake.
• Open the hood and let the engine cool until it is safe to touch.
• Place a fender cover over both front fenders to protect the paint.
• Use a 10mm socket to disconnect the negative battery cable. Move the cable aside so it cannot spring back onto the battery post.
• The 5.7L HEMI has two spark plugs per cylinder. Replace both plugs on each cylinder before moving to the next cylinder.
• A spark plug socket is a deep socket with a rubber insert or magnet that holds the plug while you remove and install it.
• A universal joint adapter lets the socket bend slightly, which helps reach the rear plugs near the firewall.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove The Engine Cover And Intake Tube

• Use both hands to lift the plastic engine cover straight upward from its rubber mounts.
• Use an 8mm socket or flat-blade screwdriver to loosen the air intake tube clamps.
• Use needle-nose pliers to release any small hose clamps attached to the intake tube.
• Remove the intake tube and set it aside.
• Take photos before unplugging anything.

Step 2: Locate The Ignition Coils

• Look along both valve covers. Each cylinder has one ignition coil assembly feeding two spark plugs.
• The ignition coil is the small electrical part bolted to the valve cover with plug wires or boots going down to the plugs.
• Work on one coil and one cylinder at a time.

Step 3: Remove One Ignition Coil

• Use your fingers or a flat-blade screwdriver to gently unlock the coil electrical connector.
• Press the connector tab and pull the connector straight off.
• Use a 10mm socket and 3/8-inch drive ratchet to remove the ignition coil retaining bolt.
• Twist the ignition coil slightly by hand, then pull it straight upward.
• Inspect the rubber boots for cracks, swelling, oil, or carbon tracking. Carbon tracking looks like thin black lightning marks.

Step 4: Clean Around The Spark Plug Wells

• Put on safety glasses.
• Use a compressed air blow gun to blow dirt and grit away from the spark plug wells.
• Do not remove the plugs until the area is clean. Dirt can fall into the engine.

Step 5: Remove The First Spark Plug

• Use a 5/8-inch spark plug socket, 6-inch extension, and 3/8-inch drive ratchet to loosen the first spark plug.
• For rear plugs, use the 5/8-inch spark plug socket, 3/8-inch universal joint adapter, and 10-inch extension.
• Turn counterclockwise slowly until the plug is free.
• Lift the spark plug out carefully with the spark plug socket.
• If the plug feels stuck, tighten it slightly, then loosen again gently.

Step 6: Remove The Second Spark Plug On The Same Cylinder

• Use the same 5/8-inch spark plug socket and extension setup to remove the second spark plug for that cylinder.
• Keep both old plugs from the same cylinder together for inspection.
• Check for oil, heavy black soot, white blistering, or broken porcelain.

Step 7: Check The New Spark Plug Gap

• Use a spark plug gap gauge to verify the new plugs match the specification on the emissions label under the hood or the plug supplier listing for your 1500.
• If the plugs are fine-wire iridium or platinum style, do not forcefully pry on the center electrode.
• If a gap is badly wrong, replace that plug instead of bending it aggressively.

Step 8: Install The First New Spark Plug By Hand

• Place one new spark plug into the 5/8-inch spark plug socket.
• Use only the extension and your fingers to start threading the plug clockwise.
• Thread it several turns by hand before using a ratchet.
• If it does not turn easily, stop, remove it, and start again.
• Hand-starting prevents expensive thread damage.

Step 9: Torque The First Spark Plug

• Attach the 3/8-inch drive torque wrench to the 5/8-inch spark plug socket and extension.
• Tighten the spark plug to Torque to 18 Nm (13 ft-lbs).
• Do not overtighten. The cylinder head is aluminum.

Step 10: Install And Torque The Second Spark Plug

• Use the 5/8-inch spark plug socket and extension to hand-start the second new spark plug.
• Use the 3/8-inch drive torque wrench to tighten the second spark plug to Torque to 18 Nm (13 ft-lbs).

Step 11: Reinstall The Ignition Coil

• Apply a very small amount of dielectric grease inside each ignition coil boot. Dielectric grease helps keep moisture out of electrical boots.
• Push the ignition coil straight down until the boots seat on both spark plugs.
• Use a 10mm socket and 3/8-inch drive torque wrench to install the coil retaining bolt.
• Tighten the ignition coil bolt to Torque to 8 Nm (71 in-lbs).
• Reconnect the electrical connector until it clicks.

Step 12: Repeat For The Remaining Cylinders

• Repeat Steps 3 through 11 for the other seven cylinders.
• Use the 3-inch, 6-inch, and 10-inch extensions as needed for access.
• Use the 3/8-inch universal joint adapter carefully on rear plugs near the firewall.
• Keep the socket straight on the plug whenever possible.
• Slow and straight wins here.

Step 13: Reinstall The Intake Tube And Engine Cover

• Set the intake tube back into position.
• Use an 8mm socket or flat-blade screwdriver to tighten the intake tube clamps snugly.
• Reconnect any hoses using needle-nose pliers if clamps were removed.
• Push the engine cover straight down onto its rubber mounts.

Step 14: Reconnect The Battery

• Use a 10mm socket to reconnect the negative battery cable.
• Tighten the terminal until it is secure and cannot twist by hand.

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✅ After Repair

• Start your 1500 and let it idle for 1-2 minutes.
• Listen for smooth idle. A rough idle usually means a coil connector, boot, or intake hose is not fully seated.
• Check that the check engine light stays off.
• Take a short test drive with gentle acceleration first, then normal acceleration.
• After the test drive, recheck the intake tube clamps with an 8mm socket or flat-blade screwdriver.
• If a misfire code appears, recheck the cylinder listed by the code before replacing more parts.

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💰 DIY vs Shop Cost

Shop Cost: $450-$750 (parts + labor)

DIY Cost: $120-$280 (parts only)

You Save: $330-$470 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 2-3 hours.

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🎯 Ready to get started?

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