🔧 Spark Plugs - Replacement

Your XC90 uses coil-on-plug ignition, so each plug sits under an ignition coil. The job is straightforward if you work on a fully cold engine and keep the plug wells clean so nothing falls into the cylinders.

Difficulty Level: Intermediate | Estimated Time: 1.5-2.5 hours

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⚠️ Safety & Precautions

• Let the engine cool completely before starting. Hot aluminum threads can strip easily.
• Do not pull on ignition wires; this engine uses individual coils.
• Keep dirt out of the spark plug wells. Debris can damage the cylinder.
• Battery disconnect is not required for this job, but keep the ignition off the whole time.
• Use care around the turbo/supercharged intake parts; they can retain heat after shutdown.

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🔧 Required Tools

You'll need the following tools for this repair:

• 3/8-inch ratchet
• 3/8-inch torque wrench
• 14mm spark plug socket
• 3/8-inch extension
• 10mm socket
• Torx T30 screwdriver
• Small pick tool
• Compressed air nozzle
• Gloves
• Safety glasses

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Spark plug set - Qty: 4

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📋 Before You Begin

• Park on level ground and set the parking brake.
• Make sure the engine is stone cold.
• Open the hood and remove any loose items near the engine bay.
• Have the new plugs ready so the old ones are not out of the engine for long.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the engine cover

• Use your hands to lift the engine cover straight up and off.
• Set it aside where it will not crack or get dirty.

Step 2: Open access to the ignition coils

• If the intake duct or any cover blocks the rear of the engine, remove it with a 10mm socket or Torx T30 screwdriver as needed.
• Keep all fasteners in order so reassembly is easy.

Step 3: Disconnect the ignition coil connectors

• Use a small pick tool to gently release each connector lock if needed.
• Pull the connector straight off the coil. Do not tug on the wiring.

Step 4: Remove the ignition coils

• Use a Torx T30 screwdriver to remove the coil hold-down bolts.
• Twist each coil slightly, then pull it straight up and out.
• Work one cylinder at a time.

Step 5: Clean the spark plug wells

• Use compressed air nozzle to blow dirt out of each plug well before removing the plugs.
• This helps keep debris out of the cylinder.

Step 6: Remove the old spark plugs

• Use a 14mm spark plug socket, 3/8-inch extension, and 3/8-inch ratchet to loosen each plug.
• Turn counterclockwise until free, then lift the plug out carefully.
• If a plug feels stuck, stop and work it slowly to avoid thread damage.

Step 7: Install the new spark plugs

• Check that the new plugs are correct for your engine and pre-gapped if supplied that way.
• Thread each plug in by hand first using the 14mm spark plug socket and extension.
• Tighten with a 3/8-inch torque wrench to 23 Nm (17 ft-lbs).
• Hand-start every plug first.

Step 8: Reinstall the ignition coils

• Push each coil straight down onto its spark plug until fully seated.
• Install the coil bolts with the Torx T30 screwdriver and tighten snugly to the factory feel. If your replacement bolt spec is available on the fastener, follow it exactly.
• Reconnect each coil connector until it clicks.

Step 9: Reassemble the intake parts and engine cover

• Reinstall any ducting or covers removed earlier using the 10mm socket or Torx T30 screwdriver.
• Press the engine cover back into place by hand.

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✅ After Repair

• Start the engine and let it idle smoothly.
• Listen for misfires, rough running, or ticking from an unplugged coil.
• If the check engine light is on, scan for misfire codes and clear them after confirming the repair.
• Take a short test drive and recheck engine operation.

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💰 DIY vs Shop Cost

Shop Cost: ₹12,000-₹20,000 (parts + labor)

DIY Cost: ₹4,000-₹8,000 (parts only)

You Save: ₹8,000-₹12,000 by doing it yourself!

Shop labor rates vary but typically run ₹4,500-₹8,000/hour. This repair takes a shop approximately 1.5-2.5 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.