🔧 CX-50 - Ignition Coil Replacement

On your CX-50, each cylinder has its own ignition coil mounted on top of the spark plug. Replacing a failing coil fixes misfires, rough idle, and flashing check-engine light issues caused by weak or intermittent spark.

Difficulty Level: Beginner | Estimated Time: 0.5-1.5 hours

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⚠️ Safety & Precautions

• ⚠️ Work on a cool engine to avoid burns and to prevent coil boot damage.
• ⚠️ Keep the ignition OFF and the key/fob away from the vehicle while unplugging coils.
• ⚠️ If the check-engine light is flashing, avoid driving until the misfire is fixed (can damage the catalytic converter).
• ⚠️ Battery disconnect is not required, but disconnecting the negative terminal is recommended if you’re nervous about electrical connectors.

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🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 1/4" drive ratchet
• 6" socket extension (1/4")
• Trim clip removal tool
• Small flat-blade screwdriver
• Torque wrench (3-30 Nm range)
• Nitrile gloves
• Safety glasses

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Ignition coil - Qty: 1 (single cylinder) or Qty: 4 (replace all)
• 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 fully cool.
• If disconnecting the battery: use a 10mm socket to remove the negative terminal and isolate it so it can’t spring back.
• Take a quick photo of coil connectors first.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the engine cover (if equipped)

• Grip the cover near the corners and pull straight up to pop it off the rubber grommets.
• If your cover uses clips, use a trim clip removal tool to release them.

Step 2: Locate the ignition coils

• The coils are the four identical units on top of the engine, each with an electrical connector and a single hold-down bolt.

Step 3: Unplug the coil electrical connector

• Press the connector lock tab by hand; if it’s stubborn, use a small flat-blade screwdriver gently to help lift the lock.
• Pull the connector straight back (don’t pull on the wires).

Step 4: Remove the coil hold-down bolt

• Use a 10mm socket with a 1/4" drive ratchet and 6" socket extension (1/4") to remove the bolt.
• Set the bolt aside where it won’t fall into the engine bay.

Step 5: Remove the ignition coil

• Twist the coil slightly left-right by hand to break the seal, then pull straight up to remove it.
• If it feels stuck, keep twisting gently—don’t pry hard on plastic parts.

Step 6: Install the new ignition coil

• Apply a very thin smear of dielectric grease inside the rubber boot (this helps prevent sticking and moisture issues).
• Push the coil straight down onto the spark plug until it seats fully.

Step 7: Reinstall and torque the coil bolt

• Start the bolt by hand first to avoid cross-threading.
• Use a torque wrench (3-30 Nm range) to tighten the bolt: Torque to 8 Nm (71 in-lbs).
• A torque wrench is a tool that measures tightening force so you don’t strip threads.

Step 8: Reconnect the electrical connector

• Push the connector on until it clicks/locks.

Step 9: Repeat for other coils (if replacing more than one)

• Repeat Steps 3-8 for each additional cylinder.
• Replace one coil at a time to avoid mix-ups.

Step 10: Reinstall engine cover and reconnect battery (if disconnected)

• Press the engine cover back onto the grommets until fully seated.
• If disconnected earlier, use a 10mm socket to tighten the negative terminal snugly.

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✅ After Repair

• Start the engine and let it idle for 1-2 minutes. The idle should be smooth.
• If you had a check-engine light, it may take a few drive cycles to clear on its own; a scan tool can clear it immediately.
• Do a short test drive and recheck that all coil connectors are fully clicked in.
• If the same misfire returns, the spark plug on that cylinder may also need inspection/replacement.

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💰 DIY vs Shop Cost

Shop Cost: $250-$550 (parts + labor)

DIY Cost: $60-$320 (parts only)

You Save: $190-$230 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 0.8-1.2 hours.

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🎯 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.