🔧 Explorer - Ignition Coil Replacement

You’ll be replacing the ignition coils on your Explorer, which sit on top of the spark plugs and create the spark your engine needs. Misfires, rough idle, or a flashing check engine light often point to a bad coil. On your V6, the front bank is easy to reach; the rear bank requires removing the upper intake manifold.

Difficulty Level: Advanced (because of rear bank) | Estimated Time: 3–5 hours

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⚠️ Safety & Precautions

• 🛑 Always work on a cool engine; hot parts and coolant can burn you.
• 🛑 Disconnect the negative battery cable before unplugging ignition coils to avoid shorts.
• 🛑 Keep metal tools and jewelry away from the battery terminals.
• 🛑 Do not pull on wires; only use the plastic connectors to unplug anything.
• 🛑 When the intake manifold is off, keep debris (sand, bolts, rags) out of the engine’s intake ports.
• 🛑 Double-check all hoses and electrical connectors are reattached before starting the engine.

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🔧 Required Tools

You'll need the following tools for this repair:

• 🧰 10mm socket
• 🧰 8mm socket
• 🧰 7mm socket
• 🧰 1/4" drive ratchet
• 🧰 3/8" drive ratchet
• 🧰 3/8" drive torque wrench (inch-lb and ft-lb capable)
• 🧰 3" socket extension
• 🧰 6" socket extension
• 🧰 Flathead screwdriver (medium size)
• 🧰 Phillips screwdriver
• 🧰 Trim removal tool (plastic)
• 🧰 Needle-nose pliers
• 🧰 Picks set (small hook pick)
• 🧰 Shop light or flashlight
• 🧰 Fender cover or clean thick towel
• 🧰 Mechanic’s gloves
• 🧰 Safety glasses
• 🧰 OBD2 scan tool (basic)

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• 🔩 Ignition coil set (3.5L EcoBoost, all 6 cylinders) - Qty: 6
• 🔩 Upper intake manifold gasket set - Qty: 1
• 🔩 Throttle body gasket - Qty: 1
• 🔩 PCV / vacuum hose o-rings (intake-related, as needed) - Qty: 1 set
• 🔩 Dielectric grease (for coil boots) - Qty: 1 small tube
• 🔩 Shop towels - Qty: 1 pack
• 🔩 Engine-safe cleaner (brake cleaner or MAF-safe intake cleaner) - Qty: 1 can

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📋 Before You Begin

• Park the Explorer on a level surface, shift to Park, and set the parking brake.
• Open the hood and support it securely with the hood prop rod.
• Note: an intake manifold is the large plastic piece on top of the engine that distributes air to each cylinder.
• Use your phone to take photos of hose routing and connectors before unplugging them. Photos make reassembly easier
• Turn ignition OFF, remove the key, wait 2–3 minutes for modules to sleep.
• Disconnect the negative battery terminal using a 10mm socket and set the cable aside so it cannot spring back.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove engine cover

• Lift off the decorative plastic engine cover. It usually pulls straight up; if stuck, gently pry under the edges with a trim removal tool.
• Set the cover aside where it cannot get stepped on.

Step 2: Disconnect air intake tube from throttle body

• Locate the large rubber/plastic tube going to the round metal throttle body at the front of the intake manifold.
• Use an 8mm socket to loosen the clamp at the throttle body.
• Loosen the other clamp on the airbox side with the same 8mm socket.
• Unplug any small sensors or vacuum lines from the tube using your flathead screwdriver to gently lift clips.
• Wiggle and remove the tube; set it aside.

Step 3: Remove throttle body (for access)

• Unplug the electrical connector on the throttle body by lifting the locking tab with a pick tool if needed.
• Use an 8mm socket with a 1/4" drive ratchet to remove the four throttle body bolts.
• Carefully pull the throttle body forward and set it on a clean towel; do not stress the coolant lines if present.
• Remove the old throttle body gasket and clean the mating surfaces with a shop towel and engine-safe cleaner.
• Do not spray cleaner into the open intake ports

Step 4: Disconnect intake manifold hoses and connectors

• Trace all hoses and connectors going to the upper intake manifold (vacuum lines, PCV hose, MAP sensor, etc.).
• Unplug each electrical connector by pressing its tab; use a pick tool gently if a tab sticks.
• Use needle-nose pliers to release any spring-type hose clamps and slide hoses off the manifold.
• Move hoses and wiring aside so they do not catch when you lift the manifold.

Step 5: Remove upper intake manifold

• Use a 10mm socket with a 3/8" drive ratchet and extension to remove all visible intake manifold bolts on top and sides.
• Keep bolts in order; some may be different lengths. Use cardboard to label bolt positions
• Gently rock the manifold by hand to break it free; if it resists, check for any hidden bolts or brackets.
• Lift the manifold straight up and toward the front, watching that nothing is still connected.
• Place the manifold upside down on a clean bench or towel.
• Immediately stuff clean shop towels into the exposed intake ports on the engine to keep debris out.

Step 6: Access and replace front bank ignition coils

• The front bank (closest to the radiator) coils are now in clear view on top of the valve cover.
• Unplug each coil’s electrical connector by pressing the tab and pulling straight back.
• Use a 7mm socket with a 1/4" drive ratchet to remove the hold-down bolt on the first coil.
• Twist the coil gently and pull upward to remove it from the spark plug.
• Apply a small amount of dielectric grease inside the new coil boot opening.
• Install the new coil, pressing it firmly onto the spark plug.
• Reinstall the hold-down bolt using the 7mm socket and snug it, then torque: Torque to 5 Nm (44 in-lbs).
• Reconnect the coil electrical connector until it clicks.
• Repeat for all three front-bank coils.

Step 7: Access and replace rear bank ignition coils

• With the intake manifold removed, the rear bank coils (near the firewall) are exposed.
• Remove any small brackets or wire looms blocking a coil using a 10mm socket if needed.
• Unplug each coil connector as in Step 6.
• Use the 7mm socket with extension to remove each coil bolt.
• Twist and remove the old coil; apply dielectric grease to the new coil boot.
• Install the new coil, press down firmly, and reinstall the bolt.
• Torque each rear coil bolt to: 5 Nm (44 in-lbs).
• Reconnect each coil connector until fully seated.

Step 8: Prepare intake manifold and install new gaskets

• Remove the old intake manifold gaskets from the underside of the manifold.
• Clean the gasket grooves with a shop towel; do not scratch the plastic.
• Install the new upper intake manifold gaskets, pressing them fully into their channels.
• Inspect the engine-side sealing surfaces around the intake ports and wipe them with a clean, lint-free towel.
• Remove the shop towels from the engine intake ports just before you reinstall the manifold. Count towels so none stay inside

Step 9: Reinstall upper intake manifold

• Carefully lower the manifold into place, aligning it with the locating dowels and bolt holes.
• Start all manifold bolts by hand with a 10mm socket and extension; do not cross-thread.
• Using a 3/8" drive ratchet, snug the bolts in a crisscross pattern from the center outward.
• Torque each upper intake manifold bolt to: 18 Nm (159 in-lbs), again working from center to outside.

Step 10: Reconnect hoses, sensors, and throttle body

• Reattach all vacuum hoses and PCV hoses you removed, using needle-nose pliers to position clamps.
• Reconnect all electrical connectors to sensors on the manifold; listen and feel for a “click.”
• Install the new throttle body gasket on the manifold.
• Position the throttle body and hand-thread its four bolts with an 8mm socket.
• Tighten bolts evenly with the 1/4" drive ratchet and torque: 10 Nm (89 in-lbs).
• Reconnect the throttle body electrical connector.

Step 11: Reinstall air intake tube and engine cover

• Reinstall the air intake tube onto the throttle body and airbox.
• Use an 8mm socket to tighten both clamps snugly; do not overtighten.
• Reconnect any sensors or hoses to the intake tube.
• Press the plastic engine cover back onto its mounting studs until fully seated.

Step 12: Reconnect battery and initial start-up

• Reconnect the negative battery terminal using a 10mm socket and tighten securely.
• Turn the ignition to ON for a few seconds to let the throttle body and modules wake up, then start the engine.
• The engine may idle slightly rough for a few seconds while it relearns; this should smooth out quickly.
• Check under the hood for any obvious hissing sounds (vacuum leaks) or disconnected hoses.

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✅ After Repair

• Use your OBD2 scan tool to clear any stored misfire or coil codes.
• Let the engine reach normal operating temperature while parked and listen for unusual noises.
• Take a short, gentle test drive (5–10 minutes) and verify there is no check engine light or loss of power.
• After the drive, recheck under the hood to confirm all hoses and connectors are still secure.

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💰 DIY vs Shop Cost

Shop Cost: $650–$900 (parts + labor)

DIY Cost: $200–$350 (parts only, all 6 coils + gaskets)

You Save: $450–$550 by doing it yourself!

Shop labor rates vary but typically run $100–$150/hour. This repair takes a shop approximately 2.5–3.0 hours.

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🎯 Ready to get started?

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