🔧 Palisade - Spark Plug Replacement

On your Palisade’s 3.8L V6, you’ll replace all 6 spark plugs. The front bank is easy to reach, but the rear bank sits under the upper intake manifold, so that manifold must come off to access the back 3 plugs.

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

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⚠️ Safety & Precautions

• ⚠️ Work on a fully cool engine to avoid burns and to prevent thread damage in the aluminum cylinder heads.
• ⚠️ Disconnect the negative battery cable before unplugging the throttle body/engine connectors.
• ⚠️ Keep dirt out of the intake ports; cover openings with clean rags as soon as the intake is removed.
• ⚠️ Do not over-tighten spark plugs; the cylinder heads are aluminum.
• ⚠️ If you smell fuel heavily during the job, stop and check for a loose EVAP/fuel vapor hose connection.

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🔧 Required Tools

You'll need the following tools for this repair:

• Safety glasses
• Nitrile gloves
• 10mm socket
• 12mm socket
• 14mm socket
• 3/8" drive ratchet
• 3/8" drive torque wrench (10–50 ft-lbs range)
• 3/8" drive extension set (3", 6", 10")
• 3/8" drive swivel/universal joint
• 5/8" spark plug socket (rubber insert or магнит type)
• Flathead screwdriver
• Needle-nose pliers
• Plastic trim tool set
• Pick tool
• Compressed air blow gun
• Clean shop rags
• Magnetic pickup tool
• Flashlight

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Spark plugs (OEM-spec for Palisade 3.8L) - 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.
• Open the hood and let the engine cool completely.
• Disconnect the battery negative terminal using a 10mm socket.
• Take photos of hose routing first.
• Quick tool terms: a torque wrench tightens bolts to an exact setting; a spark plug socket grips the plug so it doesn’t drop.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the engine cover and intake duct

• Pull up to remove the engine cover (use a plastic trim tool set if it’s tight).
• Loosen the intake duct clamps using a flathead screwdriver.
• Unplug any intake duct sensor connector(s) by hand and remove the duct.

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

• Unplug one ignition coil connector at a time (press the lock tab by hand or use a pick tool gently).
• Remove the coil hold-down bolt with a 10mm socket, then pull the coil straight up.
• Blow debris out of the spark plug well using compressed air blow gun.
• Remove the spark plug using a 5/8" spark plug socket, 3/8" drive ratchet, and a 3/8" drive extension set.
• Install the new spark plug by hand first using the 5/8" spark plug socket and extension (no ratchet) until fully seated.
• Tighten the spark plug using a 3/8" drive torque wrench: Torque to 18–22 Nm (13–16 ft-lbs).
• Apply a tiny amount of dielectric grease inside the coil boot, reinstall the coil, and tighten the coil bolt: Torque to 8–10 Nm (6–7 ft-lbs).
• Repeat for all 3 front bank plugs (do one cylinder at a time).

Step 3: Remove the upper intake manifold (to reach the rear bank)

• Disconnect any visible vacuum/PCV hoses from the upper intake using needle-nose pliers as needed (move clamps back first).
• Unplug the throttle body connector by hand.
• Remove the throttle body bolts using a 10mm socket and set the throttle body aside gently (do not stress the wiring).
• Remove the upper intake manifold mounting bolts using a 12mm socket, a 3/8" drive ratchet, and a 3/8" drive extension set.
• Lift the upper intake manifold off carefully. Immediately cover the intake openings with clean shop rags to prevent anything falling in.
• Remove and discard the old intake manifold gaskets.

Step 4: Replace the rear bank spark plugs (under the intake)

• Unplug one rear ignition coil connector at a time.
• Remove each rear coil bolt with a 10mm socket, then pull the coil straight up.
• Use compressed air blow gun to clean each spark plug well before removal.
• Remove each rear spark plug using a 5/8" spark plug socket, 3/8" drive ratchet, 3/8" drive extension set, and a 3/8" drive swivel/universal joint as needed for clearance.
• Hand-thread each new spark plug fully before tightening.
• Tighten each spark plug with a 3/8" drive torque wrench: Torque to 18–22 Nm (13–16 ft-lbs).
• Apply a small amount of dielectric grease inside each coil boot and reinstall coils: Torque to 8–10 Nm (6–7 ft-lbs).

Step 5: Reinstall the upper intake manifold and throttle body

• Remove the rags, then wipe the intake sealing surfaces with a clean rag (no scraping with metal tools).
• Install new upper intake manifold gaskets in the correct orientation.
• Set the upper intake manifold in place and start all bolts by hand.
• Tighten the intake manifold bolts evenly (crisscross pattern) using a 12mm socket and 3/8" drive torque wrench: Torque to 18–22 Nm (13–16 ft-lbs).
• Install a new throttle body gasket, reinstall the throttle body with a 10mm socket, then torque: Torque to 8–10 Nm (6–7 ft-lbs).
• Reconnect all hoses and electrical connectors (use your photos to confirm routing).

Step 6: Reinstall the intake duct and engine cover

• Reinstall the intake duct and tighten clamps with a flathead screwdriver.
• Reconnect any intake duct sensor connector(s).
• Press the engine cover back into place.

Step 7: Reconnect the battery

• Reconnect the negative battery terminal using a 10mm socket.

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✅ After Repair

• Start the engine and let it idle for 2–3 minutes. A slightly rough idle for the first minute can happen while the throttle control relearns.
• Listen for hissing (vacuum leak) around the intake and confirm there’s no check engine light.
• If a check engine light appears, recheck every intake/throttle body connector and every vacuum hose connection.
• Take a short test drive, then recheck for any warning lights.

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💰 DIY vs Shop Cost

Shop Cost: $450-$850 (parts + labor)

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

You Save: $360-$630 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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