🔧 Tucson - Spark Plug Replacement

On your Tucson, the spark plugs sit under the ignition coils on top of the engine. Replacing them restores smooth starts, fuel economy, and prevents misfires as the plugs wear.

Difficulty Level: Intermediate | Estimated Time: 1.0-2.0 hours

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⚠️ Safety & Precautions

• ⚠️ Work on a cold engine to avoid burns and stripped spark plug threads.
• ⚠️ Do not pull on wiring; release electrical connectors by the tab.
• ⚠️ Keep dirt out of the spark plug holes; blow out debris before removing plugs.
• ⚠️ Battery disconnect is not required, but it’s OK to disconnect the negative terminal if you’re worried about accidentally shorting something.

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🔧 Required Tools

You'll need the following tools for this repair:

• 10mm socket
• 3/8" drive ratchet
• 3/8" drive torque wrench (5-60 Nm range)
• 3/8" drive extension set (3" and 6")
• 5/8" spark plug socket (rubber insert or magnetic)
• Trim removal tool
• Small flat-blade screwdriver
• Compressed air blow gun
• Feeler gauge set (metric)
• Nitrile gloves
• Safety glasses

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🔩 Required Parts

HowToo sells all the parts you need for this repair:

• Spark plugs (OEM-equivalent for Tucson 2.0L) - Qty: 4
• Dielectric grease (optional) - Qty: 1

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📋 Before You Begin

• Park on level ground, shift to Park, and set the parking brake.
• Let the engine cool fully (ideally 1+ hour after driving).
• Lay out parts in order (cylinder 1 to 4) so nothing gets mixed up.

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🔨 Step-by-Step Instructions

Follow these steps in order:

Step 1: Remove the engine cover (if equipped)

• Grip the cover and pull straight upward to pop it off the rubber grommets.
• If a corner feels stuck, use a trim removal tool to lift gently.

Step 2: Unplug and remove ignition coils

• Find the ignition coils (one per cylinder) on top of the valve cover.
• Press the connector lock tab and unplug each coil; use a small flat-blade screwdriver only if the tab is stubborn.
• Remove each coil hold-down bolt using a 10mm socket and 3/8" drive ratchet.
• Pull the coil straight up to remove it. Twist slightly if it’s stuck.

Step 3: Clean the spark plug wells

• Blow compressed air down each spark plug tube using a compressed air blow gun.
• This prevents dirt from falling into the cylinder when the plug comes out.

Step 4: Remove the old spark plugs

• Install a 5/8" spark plug socket (rubber insert or magnetic) on a 3/8" drive extension (6") and 3/8" drive ratchet.
• Loosen each plug counterclockwise and lift it out with the socket.
• If a plug feels unusually tight, stop and work it gently back and forth to avoid thread damage.

Step 5: Check the new spark plug gap

• Use a feeler gauge set (metric) to confirm the gap matches the spec on the under-hood emissions label or plug box.
• Most modern Hyundai iridium plugs are pre-gapped; do not pry on the fine-tip electrode.

Step 6: Install the new spark plugs (start by hand)

• Place a new plug into the 5/8" spark plug socket and lower it into the well with a 3/8" drive extension (6").
• Thread the plug in by hand using only the extension (no ratchet) for several turns.
• If it doesn’t turn easily, back out and restart to avoid cross-threading (damaging the cylinder head threads).

Step 7: Torque the spark plugs

• Set your 3/8" drive torque wrench (5-60 Nm range) and tighten each plug.
• Torque to 18-22 Nm (13-16 ft-lbs).
• Do not use anti-seize unless the plug manufacturer specifically requires it.

Step 8: Reinstall ignition coils

• If using it, apply a tiny smear of dielectric grease (optional) inside each coil boot (it helps prevent sticking).
• Push each coil straight down until it fully seats on the plug.
• Install coil bolts using a 10mm socket and 3/8" drive ratchet.
• Torque to 8-10 Nm (71-89 in-lbs).
• Reconnect all coil electrical connectors until they click.

Step 9: Reinstall the engine cover

• Align the cover over the grommets and press down firmly to snap it into place.

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✅ After Repair

• Start the engine and let it idle for 30–60 seconds; it should run smooth.
• If the check engine light comes on or it runs rough, recheck that every coil connector is fully clicked in.
• Take a short test drive and confirm there’s no hesitation under light acceleration.

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💰 DIY vs Shop Cost

Shop Cost: $220-$450 (parts + labor)

DIY Cost: $45-$120 (parts only)

You Save: $175-$330 by doing it yourself!

Shop labor rates vary but typically run $100-$150/hour. This repair takes a shop approximately 1.0-1.5 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.