This procedure covers removal and installation of the exhaust manifold on a 2016-2024 Hyundai Tucson with 2.5L I4 AWD engine, including heat shield removal, oxygen sensor handling, and proper gasket replacement.

Warnings

Tools required

Parts

• Exhaust manifold gasket × 1 — Use OEM specification
• Exhaust flange gasket × 1 — Use OEM specification
• Exhaust manifold nuts (if damaged) × 8 — Use OEM specification
• Heat shield bolts (if damaged) × 4 — Use OEM specification
• Oxygen sensor (if replacing) × 1 — Denso or OEM equivalent

Fluids

• Hyundai/Kia Long Life Coolant (Green) — 1 qt

Preparation

1. Ensure engine is completely cold (4+ hours after last operation)
2. Disconnect negative battery cable
3. Raise vehicle and secure on jack stands with wheel chocks on rear wheels
4. Remove engine splash shield if equipped
5. Apply penetrating oil to all exhaust manifold nuts, heat shield bolts, oxygen sensor, and exhaust flange bolts. Allow to soak for 15-30 minutes
6. Place drain pan under upper radiator hose connection point

Procedure

1. 1

   Remove engine cover and air intake components
   Remove the plastic engine cover by pulling upward on the retaining clips. Loosen clamp and disconnect air intake duct from throttle body. Remove air filter housing if necessary for access. Label and disconnect any vacuum lines that interfere with manifold access.
   Torque spec

   Cover Bolts16 Nm (12 lb-ft)
2. 2

   Disconnect upper radiator hose
   Locate the upper radiator hose connection near the exhaust manifold. Use pliers to compress the spring clamp and slide it back along the hose. Twist and pull the hose off the connection point. Allow coolant to drain into the drain pan. Approximately 1 quart will drain.
   ⚠Coolant may still be warm even if engine is cool. Wear gloves to prevent skin contact.
3. 3

   Remove oxygen sensor
   Disconnect the oxygen sensor electrical connector by pressing the release tab. Using an oxygen sensor socket, turn counterclockwise to remove the sensor from the exhaust manifold. If sensor is seized, apply heat with a heat gun (not a torch) and retry. Inspect sensor threads and replace if corroded or damaged.
   ⚠Do not allow the oxygen sensor to hang by its wiring. Support the sensor or remove it completely.
   Torque spec

   O2 Sensor47 Nm (35 lb-ft)
4. 4

   Remove heat shield
   Remove the heat shield bolts securing the exhaust manifold heat shield. There are typically 4-6 bolts depending on configuration. Carefully remove the heat shield, noting the position of any spacers or washers. Inspect heat shield for damage and replace if cracked or severely corroded.
   ℹ️Heat shield bolts are small and easily stripped. Use the correct size socket and apply steady pressure.
   Torque spec

   Heat Shield Bolts10 Nm (7 lb-ft)
5. 5

   Disconnect exhaust pipe from manifold
   From underneath the vehicle, locate the exhaust flange connection between the manifold and front exhaust pipe. Remove the 2-3 flange bolts or nuts securing the connection. You may need to support the exhaust pipe with a jack or hanger to prevent strain on downstream components. Separate the flange connection and remove the old gasket.
   ⚠Exhaust flange bolts are frequently seized. Use penetrating oil and heat if necessary. Do not force or you will break the studs.
   Torque spec

   Exhaust Flange Bolts45 Nm (33 lb-ft)
6. 6

   Remove exhaust manifold mounting nuts
   Working from the engine bay, remove all exhaust manifold mounting nuts (typically 8 nuts). Start from the ends and work toward the center. Use a ratchet with extensions to access difficult fasteners near the firewall. Keep nuts organized to identify any that need replacement due to damage.
   ⚠️If a stud begins to turn with the nut, STOP immediately. Do not attempt to force it. Use a stud extractor or consult a professional to avoid cylinder head damage.
   Torque spec

   Exhaust Manifold Nuts30 Nm (22 lb-ft)
7. 7

   Remove exhaust manifold
   Carefully pull the exhaust manifold away from the cylinder head. You may need to wiggle it slightly to break the gasket seal. Work the manifold out of the engine bay, being careful not to damage surrounding components. Inspect manifold for cracks, especially between ports.
   ℹ️Manifold may be stuck to the cylinder head by old gasket material. Use gentle prying only on reinforced areas, never on the sealing surface.
8. 8

   Clean mating surfaces
   Using a plastic gasket scraper, carefully remove all old gasket material from the cylinder head and exhaust manifold mating surfaces. Follow with a wire brush if needed. Clean surfaces must be completely flat with no gasket remnants, carbon buildup, or scratches. Wipe clean with a lint-free cloth. Inspect cylinder head studs for damage and replace any that are bent, corroded, or have damaged threads.
   ⚠Do not use aggressive metal scrapers on the aluminum cylinder head as gouges will create leak paths. Use plastic scrapers only.
9. 9

   Install new exhaust manifold gasket and position manifold
   Place the new exhaust manifold gasket onto the cylinder head studs, ensuring proper orientation (check for TOP or UP markings). Carefully position the exhaust manifold onto the studs, aligning all ports with the gasket. Start all mounting nuts by hand, ensuring none are cross-threaded.
   ℹ️Some gaskets have a metal core with facing material. Ensure the smooth side faces the manifold unless otherwise specified.
10. 10

    Torque exhaust manifold nuts
    Apply a small amount of anti-seize compound to the threads of each manifold nut. Using a torque wrench, tighten the exhaust manifold nuts to 30.0 Nm (22.0 lb-ft) following the torque sequence specified in the service manual. The sequence typically works from the center outward, hot-to-cold. Perform the torque sequence in at least two stages: first to 15 Nm, then to final specification.
    ⚠️Improper torque sequence will warp the manifold and cause exhaust leaks. Consult the service manual torque sequence diagram before tightening.
    Torque spec

    Exhaust Manifold Nuts30 Nm (22 lb-ft)
11. 11

    Install heat shield
    Position the heat shield over the exhaust manifold, aligning all bolt holes. Install heat shield bolts with any spacers or washers in their original positions. Torque heat shield bolts to 10.0 Nm (7.0 lb-ft) following the sequence in the service manual, typically working in a cross pattern.
    Torque spec

    Heat Shield Bolts10 Nm (7 lb-ft)
12. 12

    Connect exhaust pipe to manifold
    Install a new exhaust flange gasket between the exhaust manifold and front exhaust pipe. Align the flange and start all bolts by hand. Apply anti-seize to the bolt threads. Torque the exhaust flange bolts to 45.0 Nm (33.0 lb-ft) following the sequence in the service manual (typically in a cross pattern).
    Torque spec

    Exhaust Flange Bolts45 Nm (33 lb-ft)
13. 13

    Install oxygen sensor
    Apply a small amount of anti-seize compound to the oxygen sensor threads (avoid getting any on the sensor tip). Thread the oxygen sensor into the exhaust manifold by hand until finger-tight. Using an oxygen sensor socket and torque wrench, tighten to 47.0 Nm (35.0 lb-ft). Reconnect the oxygen sensor electrical connector until it clicks.
    ⚠Over-tightening the oxygen sensor can damage the threads in the manifold. Use a torque wrench and do not exceed specification.
    Torque spec

    O2 Sensor47 Nm (35 lb-ft)
14. 14

    Reconnect upper radiator hose and reinstall components
    Reconnect the upper radiator hose to the fitting and secure with the spring clamp. Reinstall any vacuum lines, air intake components, and engine cover removed during disassembly. Ensure all connections are secure and no tools or parts are left in the engine bay.
    Torque spec

    Cover Bolts16 Nm (12 lb-ft)
15. 15

    Refill coolant and check for leaks
    Open the radiator cap or coolant reservoir and add Hyundai/Kia Long Life Coolant (Green) to bring the level back to the FULL mark (approximately 1 quart will be needed). Reconnect the negative battery cable. Start the engine and allow it to idle while checking for exhaust leaks at the manifold and flange connections. Listen for any unusual hissing sounds. Check coolant level again after engine reaches operating temperature and top off if needed.
    ⚠Do not open the radiator cap while the engine is hot. Allow engine to cool before adding more coolant if needed.

Reassembly

1. Reinstall engine splash shield if removed
2. Lower vehicle from jack stands
3. Double-check all fasteners for proper torque
4. Verify no tools or parts are left in engine bay or under vehicle

Verification

• Start engine and allow to idle for 5 minutes, listening for exhaust leaks at the manifold and flange connections
• Visually inspect all connections for exhaust smoke or soot indicating leaks
• Check for proper oxygen sensor operation using a scan tool (no sensor codes should be present)
• Verify coolant level is at FULL mark on reservoir after engine reaches operating temperature
• Test drive vehicle and confirm no exhaust odors enter the cabin and engine runs smoothly
• After first heat cycle (next day), re-check all exhaust manifold nuts and flange bolts for proper torque as fasteners may settle

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