🔧 Spark Plugs - Replacement

On your F-150, the spark plugs are deep in the cylinder heads, so this job takes patience and the right socket. The turbocharged 3.5L uses coil-on-plug ignition, so you’ll remove each ignition coil first, then swap the plugs one cylinder at a time.

Difficulty Level: Intermediate | Estimated Time: 2-4 hours

---

⚠️ Safety & Precautions

• Work on a cool engine only. Hot cylinder heads can damage new plugs and burn you.
• Disconnect the negative battery cable before starting.
• Keep dirt out of the plug wells. Debris can fall into the cylinder when the plug is removed.
• Do not overtighten the new plugs. The aluminum heads can be damaged easily.
• Use only the correct spark plugs for the turbocharged engine. Wrong plugs can cause misfires.

---

🔧 Required Tools

You'll need the following tools for this repair:

• 3/8-inch drive ratchet
• 5/8-inch spark plug socket
• 6-inch extension
• 10mm socket
• Torque wrench
• Trim clip tool
• Compressed air or air blow gun
• Dielectric grease
• Safety glasses
• Mechanic gloves

---

🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Spark plugs - Qty: 6
• Valve cover/coil boot grease - Qty: 1

---

📋 Before You Begin

• Park on level ground and set the parking brake.
• Let the engine cool completely.
• Disconnect the negative battery cable.
• Remove the plastic engine cover if equipped.

---

🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Disconnect power and clear access

• Use a 10mm socket to disconnect the negative battery cable.
• Remove the engine cover by lifting it off if equipped.
• If needed, remove any intake ducting that blocks access to the rear cylinders.

Step 2: Remove one ignition coil at a time

• Use a 10mm socket to remove the coil hold-down bolt.
• Unplug the coil electrical connector by releasing the tab and pulling straight back.
• Twist the coil gently and pull it out of the spark plug well.
• Keep each coil with its original cylinder.

Step 3: Clean around the plug wells

• Use compressed air or an air blow gun to blow debris away from each plug well.
• This keeps dirt from falling into the cylinder when the plug comes out.

Step 4: Remove the old spark plugs

• Use a 5/8-inch spark plug socket, 6-inch extension, and 3/8-inch drive ratchet to remove each plug.
• Turn counterclockwise and work slowly.
• If a plug feels tight, back it out a little and continue slowly to avoid thread damage.

Step 5: Install the new spark plugs

• Check that each new plug is the correct type and gap if required.
• Install each plug by hand first using the spark plug socket and extension.
• Once seated, tighten with a torque wrench to 13 Nm (115 in-lbs).
• Do not use anti-seize unless the plug manufacturer specifically says to.

Step 6: Reinstall the ignition coils

• Add a small amount of dielectric grease inside each coil boot.
• Push each coil straight down onto the new spark plug.
• Reinstall the coil bolt with a 10mm socket and tighten to 8 Nm (71 in-lbs).
• Reconnect each coil electrical connector until it clicks.

Step 7: Reassemble and reconnect power

• Reinstall any intake parts and the engine cover.
• Reconnect the negative battery cable using a 10mm socket.

---

✅ After Repair

• Start the engine and let it idle.
• Listen for smooth idle and check for misfire or rough running.
• If the check engine light is on, scan for misfire codes and verify all coil connectors are seated.
• Take a short test drive and confirm normal acceleration.

---

💰 DIY vs Shop Cost

Shop Cost: $350-$650 (parts + labor)

DIY Cost: $80-$180 (parts only)

You Save: $270-$470 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 2-4 hours.

---

🎯 Ready to get started?

HowToo makes it easy: same-day/2-day shipping on every part, plus all the tools and specialty tools you need! Check out the parts and tools sections below to add everything to your cart.