🔧 Telluride - Ignition Coil Replacement

Your Telluride uses one ignition coil per cylinder (6 total). A failing coil can cause a misfire, rough idle, flashing check-engine light, and poor power because the spark plug isn’t getting a strong spark.

Difficulty Level: Intermediate | Estimated Time: 1.5-3.5 hours

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⚠️ Safety & Precautions

• 🛑 Let the engine cool fully before starting.
• 🛑 Disconnect the negative battery cable to prevent accidental shorting.
• 🛑 If the check-engine light is flashing, avoid driving (catalytic converter damage risk).
• 🛑 Keep dirt out of open intake parts if you remove the upper intake.

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🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 10mm deep socket
• 1/4" drive ratchet
• 3/8" drive ratchet
• 3" extension
• 6" extension
• Universal joint adapter
• Torque wrench (5–30 Nm range)
• Flat trim tool
• Pick tool
• Pliers
• Shop rags
• Flashlight
• Nitrile gloves
• Safety glasses
• OBD-II scan tool (specialty)

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Ignition coil - Qty: 6 (recommended: replace all six)
• Upper intake manifold gasket set - Qty: 1 (only if upper intake is removed)
• Dielectric grease - Qty: 1 (optional)

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📋 Before You Begin

• Park on level ground, shift to Park, and set the parking brake.
• Open the hood and remove loose jewelry and long sleeves.
• Use a 10mm socket to disconnect the negative battery terminal and isolate it so it can’t spring back.
• If you’re doing only one coil due to a misfire code, write down the cylinder number first using an OBD-II scan tool (specialty) (it reads engine fault codes).

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the engine cover

• Pull upward evenly to pop the cover off its rubber grommets using your hands or a flat trim tool.
• Set it aside where it won’t get stepped on.

Step 2: Identify front-bank vs rear-bank coils

• The V6 has 3 coils at the front (radiator side) and 3 at the rear (firewall side).
• Front bank is usually straightforward; rear bank may require removing the upper intake manifold for access.

Step 3: Replace the front-bank ignition coils (easy access)

• Unplug the coil connector by lifting the lock tab with a pick tool, then press the release and pull the connector off.
• Remove the coil hold-down bolt with a 10mm socket and ratchet.
• Twist the coil slightly, then pull it straight out.
• Optional: Apply a tiny smear of dielectric grease inside the rubber boot (it helps prevent moisture and future sticking).
• Install the new coil fully down onto the spark plug.
• Install the hold-down bolt with a 10mm socket, then tighten with a torque wrench: Torque to 8–10 Nm (71–89 in-lbs).
• Reconnect the electrical connector until it clicks.

Step 4: Decide the rear-bank access path

• If you can clearly reach the rear coil bolts and connectors with a 10mm socket + 6" extension, you can replace rear coils now using the same method as Step 3.
• If access is too tight, continue to Step 5 to remove the upper intake for working room.

Step 5: Remove the upper intake manifold (only if needed for rear coils)

• Loosen the intake tube clamp(s) using pliers (spring clamp style) or a 10mm socket (worm clamp style), then move the tube aside.
• Disconnect any visible vacuum/PCV hoses by gently twisting and pulling; use pliers for clamps.
• Unplug any connectors mounted to the upper intake (press tab, pull off).
• Remove the upper intake fasteners using a 10mm socket, ratchet, and extensions.
• Lift the upper intake off carefully.
• Immediately stuff clean shop rags into the lower intake openings to keep debris out.
• Remove and discard the old upper intake gaskets if they came off with the manifold.

Step 6: Replace the rear-bank ignition coils

• Unplug each coil connector using a pick tool to gently lift the lock, then pull the connector off.
• Remove each coil hold-down bolt using a 10mm socket, ratchet, and a universal joint adapter if needed.
• Twist and pull the coil straight out.
• Install the new coil fully seated onto the spark plug.
• Reinstall the hold-down bolt and tighten with a torque wrench: Torque to 8–10 Nm (71–89 in-lbs).
• Reconnect each electrical connector until it clicks.

Step 7: Reinstall the upper intake manifold (if removed)

• Remove the shop rags from the intake ports.
• Install new upper intake gaskets onto the manifold (match the grooves/locating tabs).
• Set the upper intake back into place without pinching hoses or wiring.
• Hand-start all fasteners, then tighten evenly in a crisscross pattern using a 10mm socket and ratchet.
• Tighten the intake fasteners with a torque wrench: Torque to 18–22 Nm (13–16 ft-lbs).
• Reconnect all hoses and electrical connectors you removed.
• Reinstall the intake tube and tighten clamps using pliers or a 10mm socket.

Step 8: Reconnect the battery and reinstall the engine cover

• Reconnect the negative battery terminal using a 10mm socket.
• Press the engine cover back onto its grommets until it seats.

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✅ After Repair

• Start the engine and let it idle for 2–3 minutes; it should run smooth with no shaking.
• Check that no hoses are left disconnected and there are no hissing sounds (vacuum leak).
• Use an OBD-II scan tool (specialty) to clear codes and confirm the misfire does not return.
• Test drive 10–15 minutes, then recheck for warning lights.

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💰 DIY vs Shop Cost

Shop Cost: $350-$900 (parts + labor)

DIY Cost: $150-$450 (parts only)

You Save: $200-$450 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 1.5-3.0 hours.

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🎯 Ready to get started?

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