ignition
Ignition Coil - Single
for 2021 Hyundai Tucson 2.5L I4 · AWD
Difficulty
Easy
Time
30 min
Tools
7
Steps
9
This procedure covers the removal and replacement of a single ignition coil on the 2016-2024 Hyundai Tucson with the 2.5L I4 gas engine.
Warnings
⚠️Allow engine to cool completely before beginning work. Hot engine components can cause severe burns.
⚠Disconnect negative battery terminal and wait 3 minutes before working on ignition system to prevent electrical shock or accidental engine start.
⚠Do not force ignition coils during removal. Stuck coils can break and leave debris in cylinder.
ℹ️Mark or photograph ignition coil connector orientation before removal to ensure correct reinstallation.
Tools required
10mm socket and ratchetEssential
Spark plug socket (14mm or 16mm)
Extension bar (6-inch)Essential
Torque wrench (10-30 Nm range)Essential
Dielectric greaseEssential
Anti-seize compound
Compressed air or vacuum
Parts
- Ignition coil × 1 — Use OEM specification (Hyundai part number recommended)
- Spark plug (if damaged or at service interval) × 1 — Use OEM specification
Preparation
- Ensure engine is completely cool to the touch
- Disconnect negative battery terminal and wait at least 3 minutes
- Identify which cylinder requires coil replacement (cylinders numbered 1-4 from timing belt side)
- Remove engine cover if equipped by pulling upward on clips
- Clean debris around ignition coil area with compressed air or vacuum to prevent contamination
Procedure
- 1Disconnect ignition coil electrical connectorPress down on the locking tab of the ignition coil connector and pull straight up to disconnect. Do not twist or pull on the wiring harness itself. Note the orientation of the connector for reassembly.
- 2Remove ignition coil mounting boltUsing a 10mm socket and extension, remove the single bolt securing the ignition coil to the valve cover. Keep the bolt in a clean location for reinstallation.Torque specIgnition Coil Bolts8 Nm (6 lb-ft)
- 3Extract ignition coil from spark plug wellGrasp the ignition coil body firmly and pull straight upward with steady pressure. Use a slight twisting motion if needed, but do not force. If resistance is encountered, apply penetrating oil around the base and wait 10 minutes before attempting removal again. The coil boot should come out with the coil.⚠Excessive force can break the coil boot or damage the spark plug. If coil is severely stuck, consider using a dedicated coil puller tool.
- 4Inspect spark plug well and spark plugUse a flashlight to inspect the spark plug well for oil, coolant, or debris. If oil is present, valve cover gasket or tube seal replacement is needed. Inspect the visible portion of the spark plug for damage, excessive wear, or fouling. Replace spark plug if mileage interval has been reached or if damage is visible.
- 5Remove and replace spark plug (if necessary)If replacing the spark plug, use a spark plug socket with extension to remove the old plug by turning counterclockwise. Inspect plug condition and gap on new plug (0.043 inches for 2.5L I4). Apply a small amount of anti-seize compound to spark plug threads, avoiding the electrode area. Thread new plug by hand first to ensure proper seating, then tighten to specification.⚠Cross-threading spark plugs in aluminum heads can cause catastrophic engine damage requiring cylinder head replacement.Torque specSpark Plugs - Aluminum Head20 Nm (15 lb-ft)
- 6Prepare new ignition coilInspect the new ignition coil boot for any damage or debris. Apply a thin coat of dielectric grease to the inside of the coil boot where it contacts the spark plug terminal. This prevents moisture intrusion and ensures easy future removal.
- 7Install new ignition coilAlign the ignition coil boot with the spark plug and press down firmly until the coil seats fully against the valve cover. The coil should sit flush with no gap. Install the mounting bolt finger-tight first, then torque to specification using a torque wrench.Torque specIgnition Coil Bolts8 Nm (6 lb-ft)
- 8Reconnect electrical connectorAlign the ignition coil electrical connector with the coil terminal in the correct orientation and press down firmly until you hear and feel a positive click. Gently tug on the connector to verify it is fully locked in place.
- 9Reinstall engine cover and reconnect batteryIf an engine cover was removed, align the mounting clips and press down firmly until all clips engage. Reconnect the negative battery terminal.
Reassembly
- Ensure all electrical connectors are fully seated and locked
- Verify ignition coil mounting bolt is torqued to specification
- Confirm engine cover is properly secured if equipped
- Double-check that no tools or parts are left in the engine compartment
Verification
- Start the engine and listen for smooth idle with no misfires or rough running
- Verify no Check Engine Light illuminates after starting
- Use an OBD-II scanner to clear any stored misfire codes and confirm no new codes appear
- Rev engine gently to 2000-3000 RPM and verify smooth operation across RPM range
- Inspect ignition coil area for any signs of arcing, burning smell, or electrical noise