Replace the front exhaust gasket between the turbocharger downpipes and exhaust Y-pipe on the 3.5L EcoBoost engine. This procedure addresses exhaust leaks at the front flange connection.

Warnings

Tools required

Parts

• Front exhaust flange gasket × 1 — Use OEM Ford gasket or equivalent
• Exhaust flange bolts/nuts (if corroded) × 1 — Use OEM specification

Preparation

1. Ensure engine and exhaust system are completely cold to the touch
2. Park vehicle on level surface, apply parking brake, and place wheel chocks behind rear wheels
3. Spray all exhaust flange bolts and heat shield fasteners with penetrating oil and allow to soak for 15-30 minutes
4. Raise front of vehicle and support securely on jack stands rated for vehicle weight
5. Verify stability of vehicle on jack stands before working underneath

Procedure

1. 1

   Remove heat shields
   Remove any heat shields covering the front exhaust flange connection. These are typically held by 10mm bolts. Set heat shields and hardware aside for reinstallation.
   Torque spec

   Heat Shield Bolts10 Nm (7 lb-ft)
2. 2

   Disconnect oxygen sensors (if applicable)
   If oxygen sensors are mounted near the front flange and impede access, disconnect the electrical connectors and remove the sensors using an oxygen sensor socket. Support sensors to prevent damage to wiring. Note the orientation of each sensor for proper reinstallation.
   ⚠Oxygen sensors are fragile. Do not allow sensors to hang by their wires or contact ground while removed.
   Torque spec

   O2 Sensor45 Nm (33 lb-ft)
3. 3

   Support exhaust Y-pipe
   Use a floor jack with a block of wood to support the Y-pipe section of the exhaust system just behind the front flange. This prevents stress on rear hangers and maintains alignment during gasket replacement.
   ℹ️Do not place excessive upward pressure on the exhaust. Support only enough to prevent sagging.
4. 4

   Remove front flange bolts
   Remove the bolts connecting the turbocharger downpipes to the Y-pipe at the front flange. This connection typically uses 4-6 bolts. Use penetrating oil liberally if bolts show resistance. Work bolts loose gradually in a cross-pattern to prevent binding.
   ⚠These bolts frequently corrode and break. If a bolt breaks, the stud may need to be drilled out or extracted. Apply heat carefully if needed, avoiding damage to turbochargers.
5. 5

   Separate exhaust sections
   Carefully separate the downpipes from the Y-pipe by pulling the sections apart. You may need to gently pry or wiggle the connection to break it free. Lower the Y-pipe slightly using the support jack to create clearance.
   ⚠Do not force separation. If sections will not separate, verify all fasteners are removed and apply additional penetrating oil.
6. 6

   Remove old gasket and clean surfaces
   Remove and discard the old exhaust gasket. Use a wire brush and gasket scraper to thoroughly clean both mating surfaces on the downpipes and Y-pipe flanges. Remove all carbon deposits, old gasket material, and corrosion. Surfaces must be flat and clean for proper sealing.
   ℹ️Wear eye protection and dust mask when cleaning exhaust surfaces to avoid carbon particle exposure.
7. 7

   Inspect flange surfaces
   Inspect both flange surfaces for warping, cracks, or damage. Check that bolt holes are not elongated or stripped. If flanges are warped or damaged, the affected exhaust section must be replaced for proper sealing.
   ⚠A warped flange will cause gasket failure and exhaust leaks even with a new gasket installed.
8. 8

   Position new gasket
   Position the new exhaust gasket on the downpipe flange. Ensure the gasket is oriented correctly with any alignment tabs or holes properly positioned. Do not apply sealant to the gasket unless specifically required by manufacturer.
9. 9

   Reconnect exhaust sections
   Raise the Y-pipe into position using the support jack and align the flanges. Carefully mate the flanges together with the new gasket between them. Verify proper alignment before installing fasteners.
10. 10

    Install and torque flange bolts
    Install new or cleaned flange bolts/nuts. Apply anti-seize compound to bolt threads as specified. Start all fasteners by hand first. Tighten bolts in a cross-pattern gradually to ensure even gasket compression. Torque to specification in multiple passes, reaching final torque in the cross-pattern sequence.
    ℹ️Anti-seize is critical for future service. Use sparingly on threads only, keeping compound away from gasket surfaces.
    Torque spec

    Exhaust Flange Bolts45 Nm (33 lb-ft)
11. 11

    Reinstall oxygen sensors
    If oxygen sensors were removed, apply a thin coat of anti-seize to sensor threads only, keeping compound away from sensor tip. Thread sensors in by hand, then torque to specification. Reconnect electrical connectors ensuring secure locking.
    ⚠Never apply anti-seize to oxygen sensor tips. Contamination will cause sensor failure and false readings.
    Torque spec

    O2 Sensor45 Nm (33 lb-ft)
12. 12

    Reinstall heat shields
    Reinstall heat shields removed during disassembly. Ensure shields are properly positioned and not contacting moving components or wiring. Torque heat shield bolts to specification.
    Torque spec

    Heat Shield Bolts10 Nm (7 lb-ft)
13. 13

    Remove support and lower vehicle
    Remove the jack supporting the exhaust Y-pipe. Verify all exhaust hangers are properly seated and the system hangs naturally without binding. Lower vehicle from jack stands.

Reassembly

1. Verify all fasteners have been tightened to proper torque specifications
2. Confirm all heat shields are securely reinstalled and not contacting moving parts
3. Ensure oxygen sensor connectors are fully seated and locked if they were disconnected

Verification

• Start engine and allow to idle. Listen carefully for exhaust leaks at the front flange connection
• With engine at idle, carefully feel around the flange area for escaping exhaust gases (keep hands at safe distance from hot components)
• Perform a test drive and monitor for any exhaust noise or smell in the cabin
• After test drive and cool-down, re-inspect flange bolts for proper torque retention
• If equipped with oxygen sensors at this location, verify no check engine light or fault codes related to O2 sensors

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