🔧 Enclave - Ignition Coil Replacement

The ignition coils create the high voltage that fires the spark plugs. On your Enclave, the front-bank coils are easy to reach, but the rear-bank coils sit under the intake manifold, so that part must come off to replace those coils.

Difficulty Level: Intermediate | Estimated Time: 2.5-5.0 hours

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⚠️ Safety & Precautions

• ⚠️ Let the engine cool fully before starting (hot intake and exhaust parts burn fast).
• ⚠️ Disconnect the battery negative cable to prevent accidental shorts and misfires while unplugging coils.
• ⚠️ Do not pull on wiring; press the connector lock and pull on the connector body.
• ⚠️ Keep dirt out of intake ports—cover openings with clean shop towels immediately.
• ⚠️ No smoking/open flames—fuel vapors may be present during intake removal.

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🔧 Required Tools

You'll need the following tools for this repair:

• Safety glasses
• Nitrile gloves
• 10mm wrench
• 1/4" drive ratchet
• 3/8" drive ratchet
• 10mm socket
• 7mm socket
• 13mm socket
• 5/8" spark plug socket
• 3" extension
• 6" extension
• Universal joint adapter
• Flat trim tool
• Pick tool
• Torque wrench (in-lb)
• Torque wrench (ft-lb)
• Shop towels
• Flashlight
• OBD2 scan tool

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Ignition coil - Qty: 1-6
• Upper intake manifold gasket set - Qty: 1
• Throttle body gasket - Qty: 1
• Dielectric grease - Qty: 1
• Spark plugs - Qty: 6

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📋 Before You Begin

• Park on level ground, shift to Park, and set the parking brake.
• Open the hood and remove any loose jewelry/necklaces that can short the battery.
• Gather small containers for bolts so nothing gets lost.
• Plan your approach:
  • If you’re only replacing a front-bank coil, you may not need to remove the intake manifold.
  • If you’re replacing any rear-bank coils (closest to the windshield), you will remove the intake manifold.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Disconnect the battery

• Use a 10mm wrench to loosen the negative battery terminal and remove it.
• Tuck the cable aside so it can’t spring back onto the terminal.

Step 2: Remove the engine cover and air intake duct

• Pull up to remove the engine cover (it’s held by rubber grommets). Use a flat trim tool if it’s stubborn.
• Use a 7mm socket to loosen the intake hose clamps.
• Unplug the intake air sensor/MAF connector (press the tab; use a pick tool gently if needed).
• Lift out the intake duct and set it aside.

Step 3: Replace a front-bank coil (skip to Step 4 if doing rear-bank coils too)

• Unplug the coil electrical connector (press the lock tab, then pull straight back).
• Use a 10mm socket to remove the coil hold-down bolt.
• Twist the coil slightly, then pull it straight up and out.
• Apply a tiny amount of dielectric grease (an insulating grease that helps prevent moisture/corrosion) inside the new coil boot.
• Install the new coil, push it down firmly, and reinstall the bolt. Torque to 10 Nm (89 in-lb).
• Reconnect the coil connector until it clicks.
• Repeat for any other front-bank coils you’re replacing.

Step 4: Remove the throttle body connections (needed for intake manifold removal)

• Unplug the throttle body electrical connector.
• Disconnect any small vacuum/PCV/EVAP hoses attached near the throttle body and intake. Use a pick tool to help lift locking tabs (don’t break them).
• Tip: Take a quick photo before removing hoses.

Step 5: Remove the upper intake manifold

• Unplug any sensors and remove any wiring retainers clipped to the intake using a flat trim tool.
• Use a 10mm socket with a 6" extension to remove the upper intake manifold bolts.
• Lift the intake manifold straight up and off.
• Immediately place shop towels into the intake ports to keep dirt out.
• Remove and discard the old intake manifold gaskets.
• Torque note for reassembly: Upper intake manifold bolts: Torque to 25 Nm (18 ft-lb).

Step 6: Replace the rear-bank ignition coils

• With the intake manifold off, locate the rear-bank coils (closest to the windshield).
• Unplug each coil connector (press tab, pull connector body).
• Use a 10mm socket to remove each coil hold-down bolt.
• Twist and pull the coil straight up to remove it.
• Apply a small dab of dielectric grease inside the new coil boot.
• Install the coil and bolt. Torque to 10 Nm (89 in-lb).
• Reconnect each coil connector until it clicks.

Step 7: Optional (recommended): Replace spark plugs while coils are out

• Use a 5/8" spark plug socket, 6" extension, and 3/8" drive ratchet to remove each spark plug.
• Install new spark plugs by hand first (to avoid cross-threading), then tighten with the torque wrench. Torque to 20 Nm (15 ft-lb).
• Reinstall coils as in Steps 3 and 6.

Step 8: Reinstall the intake manifold and intake duct

• Install new upper intake manifold gaskets into the intake manifold.
• Remove the shop towels from the intake ports.
• Set the intake manifold into place and start all bolts by hand.
• Tighten bolts evenly using a 10mm socket. Torque to 25 Nm (18 ft-lb).
• If you removed the throttle body, install a new throttle body gasket, then tighten throttle body bolts using a 10mm socket. Torque to 10 Nm (89 in-lb).
• Reconnect all vacuum/PCV/EVAP hoses and electrical connectors.
• Reinstall the intake duct and tighten clamps using a 7mm socket.
• Reinstall the engine cover by pressing it down onto the grommets.

Step 9: Reconnect the battery

• Reconnect the negative battery terminal using a 10mm wrench.
• Snug it firmly (do not over-tighten and damage the terminal).

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✅ After Repair

• Use an OBD2 scan tool to clear misfire codes (if any) and check that no new codes return.
• Start the engine and let it idle for 2–3 minutes. Listen for a smooth idle.
• Check for vacuum leaks: hissing sound, rough idle, or a check engine light after intake work.
• Road test 10–15 minutes, then recheck for codes and verify power feels normal.
• Tip: Recheck intake clamps after the test drive.

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💰 DIY vs Shop Cost

Shop Cost: $450-$1,100 (parts + labor)

DIY Cost: $60-$480 (parts only, depending on 1 vs 6 coils)

You Save: $300-$700 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 2.0-4.0 hours.

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🎯 Ready to get started?

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