🔧 Telluride - Spark Plug Replacement

On your Telluride, the spark plugs sit under individual ignition coils. The front-bank plugs are straightforward, but the rear-bank plugs typically require removing the upper intake manifold to reach them.

Difficulty Level: Intermediate | Estimated Time: 2.5-4.5 hours

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⚠️ Safety & Precautions

• ⚠️ Work on a fully cool engine to avoid burns and thread damage.
• ⚠️ Disconnect the negative battery cable before unplugging coils/sensors.
• ⚠️ Keep dirt out of the intake ports—cover openings with clean shop towels.
• ⚠️ Do not drop bolts into the intake runners.
• ⚠️ If you smell fuel or hear hissing after reassembly, shut off and recheck for vacuum leaks.

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🔧 Required Tools

You'll need the following tools for this repair:

• Safety glasses
• Nitrile gloves
• Fender cover
• 10mm socket
• 12mm socket
• 3/8" drive ratchet
• 3/8" drive extension set
• 3/8" drive swivel adapter
• 5/8" (16mm) spark plug socket
• Torque wrench (10–80 ft-lbs range)
• Torque wrench (in-lb range)
• Flat-head screwdriver
• Trim clip removal tool
• Needle-nose pliers
• Compressed air blow gun
• Shop vacuum
• Shop towels
• Paint marker
• Magnetic pickup tool

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Spark plugs (OE-type iridium) - Qty: 6
• Upper intake manifold gasket set - Qty: 1
• Throttle body gasket - Qty: 1
• Dielectric grease - Qty: 1

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📋 Before You Begin

• Park on level ground, shift to Park, and set the parking brake.
• Let the engine cool completely.
• Use a 10mm socket to disconnect the negative battery terminal and isolate it so it can’t spring back.
• Lay out parts in order and label any hoses/connectors with a paint marker so they go back to the same spot.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the engine cover and open up working room

• Pull up to remove the engine cover (it’s held by grommets). Use a trim clip removal tool if it’s stubborn.
• Remove any intake ducting that blocks access using a flat-head screwdriver to loosen hose clamps.

Step 2: Replace the front-bank spark plugs (radiator side)

• Unplug each ignition coil connector by pressing the lock tab and pulling straight off.
• Remove each coil hold-down bolt using a 10mm socket.
• Pull the coil straight up and out. Apply a tiny amount of dielectric grease inside the coil boot if desired (a thin film only).
• Blow out debris from each plug well using compressed air blow gun so dirt doesn’t fall into the cylinder.
• Remove the spark plug using a 5/8" (16mm) spark plug socket, 3/8" drive ratchet, and an extension.
• Install the new spark plug by hand first (use the spark plug socket and extension only, no ratchet) to avoid cross-threading.
• Finish tightening with a torque wrench (a torque wrench measures tightening force so you don’t strip threads): Torque to 25 Nm (18 ft-lbs).
• Reinstall the ignition coil and bolt: Torque to 10 Nm (89 in-lbs).
• Reconnect the coil connector until it clicks.

Step 3: Remove the upper intake manifold to access the rear-bank plugs (firewall side)

• Disconnect the air intake tube at the throttle body using a flat-head screwdriver, then move the tube aside.
• Unplug the throttle body electrical connector and any nearby sensor connectors you need for clearance.
• Disconnect vacuum/PCV/breather hoses using needle-nose pliers for spring clamps.
• Remove the upper intake manifold fasteners using a 12mm socket and 3/8" drive ratchet.
• Lift the upper intake manifold off carefully. If it sticks, gently work it loose by hand—do not pry on sealing surfaces.
• Immediately cover the exposed intake ports with shop towels.
• Remove and discard the old upper intake manifold gaskets.

Step 4: Replace the rear-bank spark plugs (same method as front)

• Unplug each rear ignition coil connector.
• Remove coil bolts using a 10mm socket and pull coils straight out.
• Blow out each plug well using the compressed air blow gun.
• Remove rear spark plugs using the 5/8" (16mm) spark plug socket, extension set, and swivel adapter (a swivel helps the socket bend slightly for tight access).
• Install new plugs by hand first, then tighten with a torque wrench: Torque to 25 Nm (18 ft-lbs).
• Reinstall coils and bolts: Torque to 10 Nm (89 in-lbs). Reconnect connectors.

Step 5: Reinstall the upper intake manifold

• Remove the shop towels from the intake ports and verify nothing fell in.
• Install new upper intake manifold gaskets in their grooves.
• Set the upper intake manifold back into place, ensuring it sits flat and doesn’t pinch any wiring.
• Install bolts finger-tight first, then tighten evenly using a 12mm socket.
• Tighten upper intake manifold bolts with a torque wrench: Torque to 22 Nm (16 ft-lbs).
• If the throttle body was removed, install a new throttle body gasket and tighten fasteners using an in-lb torque wrench: Torque to 10 Nm (89 in-lbs).
• Reconnect all hoses and electrical connectors (listen/feel for the “click”).
• Reinstall the intake tube and tighten clamps using a flat-head screwdriver.

Step 6: Reconnect the battery and reassemble

• Reconnect the negative battery terminal using a 10mm socket.
• Reinstall the engine cover by pressing it straight down onto the grommets.
• Tip: Do a final connector/hose walkthrough.

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✅ After Repair

• Start the engine and let it idle for 2–3 minutes.
• Listen for vacuum leaks (a steady hissing) and check that idle is smooth.
• Take a short test drive. If the check engine light comes on or it misfires, recheck coil connectors and intake hose clamps.
• If you have a scan tool, check for misfire codes and clear any stored codes after confirming the fix.

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💰 DIY vs Shop Cost

Shop Cost: $450-$900 (parts + labor)

DIY Cost: $90-$220 (parts only)

You Save: $360-$680 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 2.5-4.5 hours.

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🎯 Ready to get started?

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