Exhaust Manifold Gasket

This procedure covers the removal and replacement of exhaust manifold gaskets on the 3.5L EcoBoost V6 engine, addressing exhaust leaks and restoring proper sealing.

Warnings

Tools required

Parts

• Exhaust manifold gasket set (both banks) × 1 — Use OEM specification
• Exhaust manifold studs (if damaged) × 1 — Use OEM specification
• Heat shield gaskets (if equipped) × 1 — Use OEM specification
• EGR tube gasket (if equipped) × 1 — Use OEM specification

Preparation

1. Disconnect negative battery cable and wait 10 minutes for airbag system to discharge
2. Raise and support vehicle on jack stands at all four corners for access to underside
3. Spray all exhaust manifold nuts, studs, and flange connections with penetrating oil and allow to soak (overnight recommended)
4. Remove engine cover by pulling upward on retaining clips
5. Remove air intake system and air filter housing for access to turbochargers
6. Document all electrical connector locations with photos before disconnecting

Procedure

1. 1

   Remove oxygen sensors
   Disconnect oxygen sensor electrical connectors. Using oxygen sensor socket, carefully remove both upstream and downstream oxygen sensors from exhaust manifold and downpipe. Keep sensors organized by location for reinstallation.
2. 2

   Disconnect EGR tube
   If equipped, disconnect the EGR tube from the exhaust manifold. Use a flare nut wrench to prevent rounding of the fitting. Remove mounting bolts and carefully move tube aside without kinking.
3. 3

   Remove heat shields
   Remove heat shield retaining bolts from the exhaust manifold and turbocharger area. Carefully remove heat shields and set aside. Note the location and orientation of any spacers or washers.
   Torque spec

   Heat Shield Bolts10 Nm (7 lb-ft)
4. 4

   Disconnect turbocharger coolant and oil lines
   Locate turbocharger coolant supply and return lines. Disconnect coolant hoses using hose clamp pliers. Disconnect oil supply line at banjo bolt and oil return line at lower connection. Have drain pan ready for coolant and oil spillage. Cap all openings immediately to prevent contamination.
   ⚠Coolant and oil will drain from lines. Protect surrounding components with shop towels and have drain pan positioned.
5. 5

   Remove exhaust downpipe connection
   From underneath vehicle, remove the exhaust flange bolts connecting the downpipe to the turbocharger outlet. Support the exhaust pipe with a jack or hanger to prevent strain. Separate the connection and remove old gasket.
6. 6

   Disconnect turbocharger wastegate actuator
   Disconnect the wastegate actuator rod from the wastegate arm using appropriate tools. Remove any electrical connections to the wastegate solenoid or actuator. Note the exact position of adjustments for reassembly.
   ⚠Do not force wastegate linkage. If stuck, apply penetrating oil and work gently to avoid bending delicate components.
7. 7

   Remove exhaust manifold mounting hardware
   Working from the center outward (hot-to-cold pattern), carefully loosen all exhaust manifold retaining nuts. Use penetrating oil liberally if nuts are seized. If a stud begins to turn with the nut, stop immediately and apply more penetrating oil. Remove all nuts completely.
   ⚠️Broken studs are common. If a stud breaks, it must be extracted before proceeding. Consider using heat from a torch to aid removal if studs are severely corroded.
   Torque spec

   Exhaust Manifold Nuts30 Nm (22 lb-ft)
8. 8

   Remove exhaust manifold assembly
   Carefully separate the exhaust manifold/turbocharger assembly from the cylinder head. The assembly is heavy and awkward. Work it free from the studs and maneuver out of the engine bay. Note the position of any brackets or supports for reinstallation.
   ⚠Manifold and turbocharger assembly weighs approximately 30-40 pounds. Use proper lifting technique and have a helper assist if needed.
9. 9

   Clean mating surfaces
   Using gasket scraper and wire brush, thoroughly clean the cylinder head exhaust port mating surface. Remove all old gasket material without gouging the aluminum surface. Clean with brake cleaner and lint-free cloth. Inspect for cracks or warping. Clean the manifold mating surface similarly if reusing manifold.
   ⚠Do not use power tools or aggressive methods on aluminum cylinder head surface. Hand scraping only to prevent damage.
10. 10

    Inspect and replace studs if necessary
    Inspect all exhaust manifold studs for damage, corrosion, or stripped threads. Replace any damaged studs by threading them out with stud removal tool or locking pliers. Clean threads in cylinder head with thread chaser. Install new studs hand-tight, then torque to specification.
    Torque spec

    Exhaust Manifold Studs15 Nm (11 lb-ft)
11. 11

    Install new gaskets and position manifold
    Position new exhaust manifold gaskets on cylinder head studs. Ensure gaskets are oriented correctly with any alignment tabs or markings facing proper direction. Carefully lift manifold/turbocharger assembly and guide onto studs. Support assembly weight while starting all nuts by hand.
    ℹ️Do not apply sealant to exhaust manifold gaskets unless specifically required by gasket manufacturer.
12. 12

    Torque exhaust manifold nuts
    Apply anti-seize compound to exhaust manifold nut threads. Install all nuts finger-tight first. Using torque wrench, tighten nuts in a hot-to-cold pattern (center studs first, working outward) to specification in two stages: first to 15 Nm, then final pass to 30 Nm.
    ⚠Hot-to-cold tightening sequence is critical to prevent warping and ensure even gasket compression.
    Torque spec

    Exhaust Manifold Nuts30 Nm (22 lb-ft)
13. 13

    Reconnect turbocharger lines and wastegate
    Reconnect turbocharger oil supply line with new crush washers. Reconnect oil return line. Reconnect coolant supply and return hoses with new clamps. Reconnect wastegate actuator rod to wastegate arm and any electrical connections. Verify all connections are secure.
14. 14

    Install downpipe and heat shields
    Position new exhaust flange gasket at turbocharger outlet. Raise downpipe into position and install flange bolts with anti-seize compound. Torque flange bolts evenly in cross pattern. Reinstall heat shields with new gaskets if necessary.
    Torque spec

    Heat Shield Bolts10 Nm (7 lb-ft)
15. 15

    Install oxygen sensors and complete reassembly
    Apply anti-seize compound to oxygen sensor threads only (avoid getting compound on sensor tip). Install oxygen sensors and torque to specification. Reconnect all electrical connectors. Install EGR tube with new gasket if equipped. Reinstall air intake system and engine cover.

Reassembly

1. Verify all fasteners are torqued to specification and no tools or parts are left in engine bay
2. Reconnect negative battery cable
3. Check engine oil level and top off if necessary due to turbo oil line disconnection
4. Check coolant level and top off with Motorcraft Orange Coolant to proper level
5. If second bank requires service, repeat entire procedure for opposite side

Verification

• Start engine and allow to idle. Listen for any exhaust leaks at manifold gasket area
• Monitor for any coolant or oil leaks around turbocharger connections during warm-up
• Rev engine gently to 2000-2500 RPM and listen for leaks under load
• Check for diagnostic trouble codes related to oxygen sensors or turbocharger function
• Test drive vehicle and verify proper boost operation and no exhaust odors in cabin
• After engine reaches operating temperature and cools, re-check exhaust manifold nut torque as a final verification

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