🔧 Ranger - Ignition Coil Replacement

Replacing the ignition coils on your Ranger is a straightforward repair. The ignition coils sit on top of the engine and send high voltage to the spark plugs; a weak coil can cause misfires, rough idle, poor fuel economy, or a flashing check engine light.

Difficulty Level: Beginner | Estimated Time: 30-60 minutes

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⚠️ Safety & Precautions

• ⚠️ Let the engine cool completely before working near the turbocharged engine and intake components.
• ⚠️ Disconnect the negative battery cable before unplugging ignition coils to prevent accidental electrical shorts.
• ⚠️ Do not pull on wiring. Always release the connector lock first.
• ⚠️ Work on one coil at a time if you are new to this repair so nothing gets mixed up.
• ⚠️ If the check engine light is flashing, avoid driving until the misfire is fixed because catalytic converter damage can occur.

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🔧 Required Tools

You'll need the following tools for this repair:

• 8mm socket
• 10mm socket
• 1/4-inch drive ratchet
• 1/4-inch drive extension 6-inch
• Torque wrench inch-pound 1/4-inch drive
• Plastic trim removal tool
• Needle-nose pliers
• Compressed air blow gun
• Safety glasses
• Nitrile gloves

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Ignition coil - Qty: 1-4
• Dielectric grease - Qty: 1 small tube

Tip: If one coil has failed, you can replace only the failed coil. If mileage is high and multiple misfire codes are present, replacing all four as a set is often cleaner.

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📋 Before You Begin

• 🅿️ Park your Ranger on level ground and set the parking brake.
• ❄️ Make sure the engine is cool to the touch.
• 🔋 Use a 10mm socket to disconnect the negative battery cable and move it aside so it cannot spring back onto the terminal.
• 🧠 If replacing a specific failed coil, note the cylinder position before removal. Cylinder 1 is at the front of the engine, closest to the radiator.
• 📌 Dielectric grease is a non-conductive silicone grease that helps seal moisture out of the coil boot.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Open the Hood and Locate the Ignition Coils

• Use the hood release inside the cabin, then lift and support the hood.
• The ignition coils are mounted on top of the engine, one coil per cylinder.
• Each coil has an electrical connector and a small retaining bolt.
• Take a photo before disassembly.

Step 2: Remove Any Access Covers or Obstructions

• If a plastic engine appearance cover is installed, lift it upward by hand or use a plastic trim removal tool gently at the mounting points.
• If any wire harness clips are blocking access, release them carefully with a plastic trim removal tool.
• Do not force plastic clips. Cold plastic can crack.

Step 3: Clean Around the Coil Area

• Put on safety glasses.
• Use a compressed air blow gun to blow dust and grit away from the ignition coil area.
• This helps keep dirt from falling into the spark plug well after the coil is removed.

Step 4: Unplug the Ignition Coil Connector

• Use your fingers to press the connector release tab.
• If the connector is stuck, use needle-nose pliers gently on the release tab only.
• Pull the connector straight back from the coil.
• Do not pull on the wires.

Step 5: Remove the Coil Retaining Bolt

• Use an 8mm socket, 1/4-inch drive ratchet, and 1/4-inch drive extension 6-inch to remove the ignition coil retaining bolt.
• Place the bolt somewhere safe so it does not fall into the engine bay.

Step 6: Remove the Old Ignition Coil

• Grip the top of the coil by hand.
• Twist the coil slightly left and right to loosen the rubber boot.
• Pull the coil straight upward out of the spark plug well.
• If the rubber boot stays stuck on the spark plug, use needle-nose pliers carefully to remove it.
• Twist first, then pull upward.

Step 7: Inspect the Coil and Spark Plug Well

• Look inside the spark plug well using good light.
• Check for engine oil, coolant, water, carbon tracking, or rust.
• Carbon tracking looks like thin black lightning marks on the coil boot.
• If oil is present in the well, the valve cover sealing area may need service before installing coils.

Step 8: Prepare the New Ignition Coil

• Apply a very small amount of dielectric grease inside the end of the new coil boot.
• Use only a thin film. Too much grease can prevent the boot from seating fully.
• Compare the new coil to the old coil before installing it.

Step 9: Install the New Ignition Coil

• Slide the new ignition coil straight down into the spark plug well by hand.
• Push firmly until you feel the boot seat onto the spark plug.
• Make sure the bolt hole lines up with the mounting point.

Step 10: Reinstall the Coil Retaining Bolt

• Start the retaining bolt by hand first to avoid cross-threading.
• Use the 8mm socket, 1/4-inch drive extension 6-inch, and torque wrench inch-pound 1/4-inch drive to tighten the bolt.
• Torque to 8 Nm 71 in-lbs.
• Do not overtighten. The valve cover mounting boss can be damaged.

Step 11: Reconnect the Electrical Connector

• Push the ignition coil connector straight onto the coil until it clicks.
• Gently tug the connector body by hand to make sure it is locked.

Step 12: Repeat for the Other Coils if Needed

• If replacing more than one coil, repeat Steps 4 through 11 for each remaining coil.
• Use the same 8mm socket, 1/4-inch drive ratchet, and torque wrench inch-pound 1/4-inch drive.
• Torque each coil bolt to 8 Nm 71 in-lbs.

Step 13: Reinstall Any Covers or Clips

• Reattach any wire harness clips by hand.
• If the engine cover was removed, press it back into place by hand until seated.
• Use the plastic trim removal tool only if you need to guide a clip into place.

Step 14: Reconnect the Battery

• Place the negative battery cable back onto the battery terminal.
• Use a 10mm socket and 1/4-inch drive ratchet to tighten the terminal nut snugly.
• Do not overtighten the battery terminal.

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✅ After Repair

• ✅ Start your Ranger and let it idle for 1-2 minutes.
• ✅ Listen for smooth idle and make sure the engine is not shaking.
• ✅ If a check engine light was on, it may turn off after a few drive cycles if the misfire is fixed.
• ✅ If you have a scan tool, clear the misfire code and recheck for pending codes after a test drive.
• ✅ Take a short 10-15 minute drive with light throttle first, then recheck idle quality.
• ✅ If the same cylinder misfire returns, the spark plug, injector, wiring, or compression may need diagnosis.

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💰 DIY vs Shop Cost

Shop Cost: $180-$550 parts + labor, depending on whether one coil or all four are replaced

DIY Cost: $45-$280 parts only

You Save: $100-$270 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 0.5-1.0 hours.

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