This procedure covers the replacement of broken or damaged exhaust manifold studs on the 3.5L EcoBoost V6 engine, including removal of turbochargers and exhaust components to access the manifolds.

Warnings

Tools required

Parts

• Exhaust manifold stud kit × 1 — Use OEM specification
• Turbocharger to exhaust manifold gasket (left) × 1 — Use OEM specification
• Turbocharger to exhaust manifold gasket (right) × 1 — Use OEM specification
• Exhaust manifold to cylinder head gaskets × 2 — Use OEM specification
• Downpipe flange gaskets × 2 — Use OEM specification
• Heat shield hardware × 1 — Use OEM specification

Preparation

1. Park vehicle on level ground and allow engine and exhaust system to cool completely (minimum 4 hours)
2. Disconnect negative battery terminal and wait 10 minutes for system capacitors to discharge
3. Raise and safely support vehicle on jack stands at manufacturer lift points
4. Remove engine cover by pulling upward on clips
5. Apply penetrating oil to all exhaust fasteners and allow to soak for 30 minutes minimum
6. Document turbocharger connections with photos or tags for reassembly reference

Procedure

1. 1

   Remove air intake system
   Disconnect mass airflow sensor electrical connector. Loosen clamps on air intake tube and remove entire air intake assembly from throttle body to air filter housing. Remove acoustic cover if equipped. This provides access to the top of the engine and turbocharger inlet components.
2. 2

   Disconnect turbocharger oil and coolant lines
   Locate oil feed line at top of each turbocharger and coolant lines at turbo housings. Use flare nut wrenches to prevent rounding. Disconnect oil feed lines and both coolant supply and return lines from the turbocharger(s) requiring service. Cap or plug all open lines to prevent contamination. Have shop rags ready to catch residual oil and coolant.
3. 3

   Remove oxygen sensors
   Disconnect electrical connectors from upstream oxygen sensors on the affected bank(s). Use oxygen sensor socket to remove sensors from exhaust manifolds. Inspect sensor threads and apply anti-seize to threads only (not sensor tip) if reusing. Set aside in clean area.
   Torque spec

   O2 Sensor45 Nm (33 lb-ft)
4. 4

   Disconnect exhaust downpipes
   From underneath vehicle, locate downpipe flange connections at turbocharger outlets. Remove exhaust hanger bolts to provide flexibility. Remove flange bolts connecting downpipes to turbocharger outlets. Lower and support downpipes with wire or jack stand. Remove and discard old flange gaskets.
   Torque spec

   Exhaust Flange Bolts45 Nm (33 lb-ft)

   Hanger Bolts23 Nm (17 lb-ft)
5. 5

   Remove heat shields
   Remove heat shield bolts securing shields around exhaust manifolds and turbochargers. These shields may have multiple sections. Remove all shields from the affected bank to access manifold hardware. Some shields may be difficult to maneuver around engine components.
   Torque spec

   Heat Shield Bolts10 Nm (7 lb-ft)
6. 6

   Remove turbocharger assembly
   Working from above and below, remove bolts securing turbocharger to exhaust manifold. The turbocharger is heavy and bolted from underneath. Support turbocharger weight while removing final fasteners. Carefully lower turbocharger and remove from engine bay. Remove and discard gasket between turbocharger and manifold.
7. 7

   Remove exhaust manifold
   Remove remaining fasteners securing exhaust manifold to cylinder head. Work systematically from outside bolts toward center. If studs are broken, some fasteners may already be loose or missing. Carefully remove manifold from cylinder head and set on clean work surface. Remove old gasket material from cylinder head surface using plastic scraper (do not use metal tools on aluminum head).
   ⚠Do not pry on manifold or cylinder head surfaces. If manifold is stuck, apply penetrating oil and gently tap with plastic mallet.
8. 8

   Extract broken studs
   Identify all broken studs in cylinder head. Apply penetrating oil and let soak. Center punch each broken stud carefully. Start with smallest left-hand drill bit and progressively increase size, drilling into center of broken stud. Often the stud will begin to unthread as you drill. If not, use appropriate size stud extractor. Work slowly and keep drill perpendicular to prevent walking into threads.
   ⚠️Drilling into aluminum requires care. Stop frequently to clear chips with shop vacuum. Any metal debris left in cylinder will cause catastrophic engine damage.
   ⚠If extractor breaks or stud cannot be removed, cylinder head may require professional repair or replacement.
9. 9

   Clean and chase threads
   Once all broken studs are removed, use shop vacuum to remove all metal chips from area. Clean stud holes thoroughly with brake cleaner and compressed air. Run appropriate thread chaser (M8 x 1.25 typical for EcoBoost manifold studs) through each hole to clean threads. Vacuum again after chasing. Inspect threads for damage. Severely damaged threads may require helicoil installation.
   ⚠️Ensure absolutely no metal debris remains in or around cylinder head. Cover open ports with clean shop towels during this process.
10. 10

    Install new exhaust manifold studs
    Apply small amount of anti-seize to stud threads. Thread new studs into cylinder head by hand, turning only the bottom nut portion or using stud installer tool. Ensure studs are seated properly and perpendicular to head surface. Tighten studs to manufacturer specification (typically hand-tight plus 1/4 turn for press-fit studs, but verify with stud kit instructions).
11. 11

    Install exhaust manifold
    Place new exhaust manifold gasket on cylinder head, aligning all stud holes. Carefully position exhaust manifold onto studs and gasket. Install new nuts onto studs finger-tight. Tighten nuts in progressive stages using crisscross pattern from center outward. Final torque specification is typically 15-20 Nm for manifold nuts, working in 3 stages to prevent warping. Verify with service manual for exact specification.
    ℹ️EcoBoost manifold nut torque specs not provided in database. Consult Ford service manual for exact values. Typical range is 15-20 Nm, but verification is essential.
12. 12

    Reinstall turbocharger
    Position new gasket between exhaust manifold and turbocharger mounting flange. Carefully lift turbocharger into position, aligning mounting studs or bolt holes. Install and finger-tighten all fasteners. Torque turbocharger mounting bolts/nuts using specified pattern to prevent gasket leaks.
    Torque spec

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

    Reconnect turbocharger lines and exhaust
    Reconnect oil feed lines to turbocharger, ensuring proper sealing. Reconnect coolant supply and return lines, routing exactly as originally installed. Install new downpipe flange gaskets and reconnect exhaust downpipes. Install and torque all flange bolts and exhaust hangers.
    Torque spec

    Exhaust Flange Bolts45 Nm (33 lb-ft)

    Hanger Bolts23 Nm (17 lb-ft)
14. 14

    Reinstall oxygen sensors and heat shields
    Apply anti-seize to oxygen sensor threads only (avoid getting compound on sensor tip). Install oxygen sensors and torque to specification. Reinstall all heat shields and secure with new or reusable hardware.
    Torque spec

    O2 Sensor45 Nm (33 lb-ft)

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

    Reinstall air intake and complete assembly
    Reinstall air intake system, ensuring all clamps are tight and mass airflow sensor is connected. Reinstall engine cover. Reconnect negative battery terminal. Remove vehicle from jack stands.

Reassembly

1. Double-check all fastener torque values, especially exhaust flange connections and oxygen sensors
2. Verify all electrical connectors are properly seated and locked
3. Confirm all coolant and oil lines are properly connected and secured with no cross-threading
4. Ensure heat shields are properly positioned and not contacting moving components

Verification

• Start engine and listen for exhaust leaks at manifold, turbocharger, and downpipe connections
• Check for oil or coolant leaks at turbocharger connections after engine reaches operating temperature
• Monitor for check engine light or turbocharger-related fault codes
• Test drive vehicle and verify normal boost operation and no unusual exhaust sounds
• After 50-100 miles, re-torque accessible exhaust fasteners and recheck for leaks

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