How to Replace Ignition Coils on a 2018 Honda Ridgeline (Fix Misfire & Rough Idle)
Step-by-step front and rear bank coil replacement with tools, parts, intake removal tips, and torque specs for 2017, 2018, 2019, 2020
How to Replace Ignition Coils on a 2018 Honda Ridgeline (Fix Misfire & Rough Idle)
Step-by-step front and rear bank coil replacement with tools, parts, intake removal tips, and torque specs for 2017, 2018, 2019, 2020
🔧 Ridgeline - Ignition Coil Replacement
Your Ridgeline uses one ignition coil per cylinder (6 total). Replacing a bad coil can fix misfires, rough running, and a flashing check engine light. The front bank is straightforward; the rear bank requires removing the upper intake manifold to access the coils.
Difficulty Level: Intermediate | Estimated Time: 1.5-3.5 hours
⚠️ Safety & Precautions
- ⚠️ Work on a fully cool engine to avoid burns.
- ⚠️ Disconnect the negative battery cable to prevent accidental shorting.
- ⚠️ Keep dirt out of the intake—cover openings with clean shop towels.
- ⚠️ Do not pull on wiring; release connector locks first.
🔧 Required Tools
You'll need the following tools for this repair:
- 10mm socket
- 10mm wrench
- 3/8" ratchet
- 3/8" torque wrench (5–60 Nm range)
- 3/8" extension set (3" and 6")
- Flat-blade screwdriver
- Trim clip removal tool
- Needle-nose pliers
- Pick tool
- Flashlight
- Shop towels
- Nitrile gloves
- Safety glasses
🔩 Required Parts
HowToo sells all the parts you need for this repair:
- Ignition coil - Qty: 6 (replace as needed)
- Upper intake manifold gasket set - Qty: 1 (required if removing manifold)
- Throttle body gasket - Qty: 1 (recommended if throttle body is removed)
- Dielectric grease - Qty: 1 (helps prevent moisture in boots)
📋 Before You Begin
- Park on level ground, shift to Park, and set the parking brake.
- Let the engine cool completely.
- Use a 10mm wrench to disconnect the negative battery terminal and isolate it so it can’t spring back.
- If you’re chasing a misfire, note the cylinder number from your scan tool before removing anything.
🔨 Step-by-Step Instructions
Follow these steps in order:
Step 1: Remove the engine cover
- Grip the engine cover and pull upward to release the rubber grommets (it’s a press-fit cover).
- Set it aside so it won’t get stepped on.
Step 2: Remove the air intake tube (to create working space)
- Use a flat-blade screwdriver to loosen the hose clamps on the intake tube.
- Disconnect any small breather/PCV hoses using needle-nose pliers if spring clamps are used.
- Lift the intake tube out and set it aside.
- Tip: Take a quick photo for hose routing.
Step 3: Replace front bank ignition coils (easy access side)
- Locate the coils on the front bank (closest to the radiator).
- For each coil: press the connector lock and unplug it. Use a pick tool gently if the lock is stuck (don’t break it).
- Remove the coil hold-down bolt using a 10mm socket.
- Twist the coil slightly and pull straight up to remove it from the spark plug tube.
- Apply a tiny smear of dielectric grease inside the rubber boot (dielectric grease is a non-conductive grease that helps seal out moisture).
- Install the new coil fully seated, reinstall the bolt, and Torque to 12 Nm (9 ft-lbs) using a torque wrench.
- Reconnect the electrical connector until it clicks.
Step 4: Gain access to rear bank coils (upper intake manifold removal)
- Disconnect vacuum/air hoses and electrical connectors attached to the upper intake manifold. Use needle-nose pliers for spring clamps and a trim clip removal tool for any push-clips.
- Remove the upper intake manifold fasteners using a 10mm socket with a 3/8" extension.
- Lift the upper intake manifold off carefully.
- Immediately cover the lower intake ports with shop towels so nothing can fall in.
Step 5: Replace rear bank ignition coils
- With the rear bank exposed, unplug each coil connector (use a pick tool gently if needed).
- Remove each hold-down bolt using a 10mm socket.
- Remove the coil by twisting slightly and pulling straight up.
- Apply a small amount of dielectric grease inside the boot and install the new coil.
- Reinstall the bolt and Torque to 12 Nm (9 ft-lbs) using a torque wrench.
- Reconnect each electrical connector until it clicks.
Step 6: Reinstall the upper intake manifold
- Remove the shop towels covering the intake ports.
- Install new upper intake manifold gaskets (recommended once the manifold is removed).
- Set the upper intake manifold back in place, hand-start all fasteners.
- Tighten in a crisscross pattern using a 10mm socket, then Torque to 22 Nm (16 ft-lbs) using a torque wrench.
- Reconnect all hoses and connectors exactly as removed.
Step 7: Reinstall the intake tube and engine cover
- Reinstall the intake tube and tighten hose clamps using a flat-blade screwdriver.
- Reinstall any breather hoses and clamps using needle-nose pliers.
- Press the engine cover back onto its grommets.
Step 8: Reconnect the battery
- Reconnect the negative battery terminal using a 10mm wrench.
✅ After Repair
- Start the engine and listen for smooth idle (no shaking).
- If the check engine light was on, clear codes with your scan tool and confirm the misfire does not return.
- Test drive 10–15 minutes and re-check for warning lights.
- Recheck that every coil connector is fully clicked in.
💰 DIY vs Shop Cost
Shop Cost: ₹9,000–₹22,000 (parts + labor, depending on how many coils)
DIY Cost: ₹3,500–₹15,000 (parts only, depending on how many coils)
You Save: ₹5,000–₹10,000+ by doing it yourself!
Shop labor rates vary but typically run ₹800–₹1,500/hour. This repair takes a shop approximately 1.5–3.0 hours.
🎯 Ready to get started?
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