🔧 Impala - Ignition Coil Replacement

On your Impala’s 3.5L V6, the ignition coils create the high voltage that fires the spark plugs. A weak or failed coil can cause misfires, rough idle, poor power, and a flashing check-engine light.

Difficulty Level: Beginner | Estimated Time: 0.5-1.5 hours

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⚠️ Safety & Precautions

• ⚠️ Work on a cool engine to avoid burns.
• ⚠️ Disconnect the negative battery cable before unplugging ignition electrical connectors.
• ⚠️ Do not pull on spark plug wires by the wire—only by the boot (the thick rubber end).
• ⚠️ Keep plug wires routed exactly like factory to prevent crossfire and misfires.

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🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 1/4" ratchet
• 3" socket extension
• Torque wrench (in-lb or Nm range)
• Small flat-blade screwdriver
• Needle-nose pliers
• Masking tape
• Paint marker
• Shop rags
• Safety glasses
• Nitrile gloves

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Ignition coil - Qty: 1 (or Qty: 3 if replacing all)
• Dielectric grease - Qty: 1
• Spark plug wire set - Qty: 1 (recommended if wires are old/brittle)

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📋 Before You Begin

• Park on level ground, shift to Park, and set the parking brake.
• Open the hood and let the engine cool fully.
• Disconnect the negative battery cable using a 10mm socket and move it aside so it can’t spring back.
• Label spark plug wires with masking tape and a paint marker before removing anything.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Locate and label the ignition coil(s)

• Find the ignition coil pack/coil assembly near the top/front area of the engine.
• Use masking tape and a paint marker to label each plug wire position on the coil(s) before removal.
• Note: Cylinder numbering on this V6 is typically rear bank 1-3-5 and front bank 2-4-6; keep wire routing exactly the same.

Step 2: Remove spark plug wires from the coil

• Grip each wire by the boot (thick rubber end), twist it slightly, then pull it off the coil tower.
• If a boot is stubborn, use needle-nose pliers gently on the boot only (not the wire).
• Twist first—pulling straight helps prevent damage.

Step 3: Unplug the coil electrical connector(s)

• Release the connector lock using a small flat-blade screwdriver (if equipped), then unplug by hand.
• Do not yank on the wiring—only pull on the connector body.

Step 4: Remove the ignition coil(s)

• Remove the coil mounting bolts using a 10mm socket, 1/4" ratchet, and 3" socket extension.
• Lift the coil straight off the bracket/module.
• If you’re replacing just one coil, match the old coil’s position to the new one before installing.

Step 5: Install the new ignition coil(s)

• Set the new coil into place, making sure it sits flat and the bolt holes line up.
• Start bolts by hand to avoid cross-threading, then tighten with a 10mm socket.
• Final tighten using a torque wrench (a tool that tightens bolts to a precise setting): Torque to 10 Nm (89 in-lbs).

Step 6: Reconnect electrical connector(s)

• Push the connector(s) on until fully seated and locked.
• Lightly tug to confirm it’s latched.

Step 7: Reinstall spark plug wires (correct order matters)

• Apply a very thin film of dielectric grease inside each plug wire boot.
• Push each wire boot onto the correct coil tower until you feel/hear it “click” into place.
• Route wires through the factory clips/holders to keep them away from hot or moving parts.

Step 8: Reconnect the battery

• Reconnect the negative battery cable using a 10mm socket.
• Snug the terminal so it doesn’t rotate by hand.

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✅ After Repair

• Start the engine and let it idle for 1-2 minutes; it should run smooth with no shaking.
• Verify the check-engine light is off; if it’s on, scan for codes and clear them after confirming the fix.
• Test drive 10-15 minutes and recheck for misfire symptoms.
• If you still have a misfire, the next most common causes are spark plugs, plug wires, or a vacuum leak.

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💰 DIY vs Shop Cost

Shop Cost: $200-$450 (parts + labor)

DIY Cost: $40-$180 (parts only)

You Save: $160-$270 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 0.7-1.3 hours.

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🎯 Ready to get started?

HowToo makes it easy: same-day/2-day shipping on every part, plus all the tools and specialty tools you need! Check out the parts and tools sections below to add everything to your cart.