Replace the front exhaust gasket between the turbocharger outlet and the exhaust downpipe on the 3.5L EcoBoost engine.

Warnings

Tools required

Parts

• Front exhaust gasket (turbo outlet to downpipe) × 1 — Use OEM specification
• Exhaust flange bolts/nuts (if corroded) × 4 — Use OEM specification

Preparation

1. Ensure engine and exhaust system are completely cold
2. Raise and support vehicle securely on jack stands at appropriate lift points
3. Spray all exhaust flange bolts and nuts with penetrating oil and allow to soak for 15-20 minutes
4. Disconnect negative battery terminal if removing oxygen sensors

Procedure

1. 1

   Remove heat shields
   Remove the exhaust heat shields covering the turbocharger outlet and front exhaust connection. These are typically secured with 10mm bolts. Remove shields carefully to avoid bending.
   Torque spec

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

   Disconnect oxygen sensor (if present)
   If an oxygen sensor is mounted near the front exhaust flange, disconnect the electrical connector and carefully remove the sensor using an 18mm wrench or O2 sensor socket. Avoid damaging the wiring harness. Apply anti-seize to threads only upon reinstallation.
   ⚠Never apply anti-seize to oxygen sensor element or connector. Apply only to threads.
   Torque spec

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

   Support exhaust system
   Position a jack or support stand under the exhaust system downstream of the front connection point to prevent excessive movement or stress on hangers when flange is disconnected.
   ℹ️Supporting the exhaust prevents damage to downstream hangers and makes reassembly easier.
4. 4

   Remove exhaust hanger bolts
   If the front exhaust hanger is preventing access to the flange, remove the hanger mounting bolts (typically 13mm). This will provide better clearance for accessing the flange connection.
   Torque spec

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

   Remove front exhaust flange bolts
   Remove the bolts or nuts connecting the turbocharger outlet to the front exhaust pipe. These are typically 15mm fasteners. Work slowly and apply additional penetrating oil if resistance is encountered. There are usually 3-4 fasteners at this connection.
   ⚠If a bolt begins to strip or round, stop immediately and use a bolt extractor set. Broken exhaust studs require additional repair time.
   Torque spec

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

   Separate exhaust flange
   Carefully pull the front exhaust pipe away from the turbocharger outlet flange. Use a pry bar if needed, but avoid damaging the flange surfaces. The old gasket may be stuck to one or both surfaces.
   ℹ️The exhaust system weight may make separation difficult. Use the support jack to adjust height and angle as needed.
7. 7

   Remove old gasket material
   Remove the old exhaust gasket completely from both the turbocharger outlet flange and the exhaust pipe flange. Use a wire brush and gasket scraper to clean both mating surfaces thoroughly. Remove all carbon deposits and old gasket material to ensure a proper seal.
   ⚠Inspect both flange surfaces for warping, cracks, or damage. Damaged flanges will cause exhaust leaks regardless of new gasket quality.
8. 8

   Install new exhaust gasket
   Position the new front exhaust gasket on the turbocharger outlet flange. Ensure the gasket is properly oriented and aligned with all bolt holes. Most gaskets have a specific installation direction - check for markings indicating which side faces the engine.
   ℹ️Some gaskets use metal reinforcement rings - ensure these are positioned correctly according to manufacturer specifications.
9. 9

   Reconnect exhaust flange
   Guide the front exhaust pipe back onto the turbocharger outlet, aligning the flange bolt holes. You may need to adjust the support jack position to achieve proper alignment. Start all bolts or nuts by hand before tightening any of them.
   ⚠Do not force alignment - misalignment indicates a problem with exhaust system positioning or support.
10. 10

    Torque exhaust flange bolts
    Apply anti-seize compound to the exhaust flange bolt threads. Tighten the flange bolts in a cross-pattern sequence to ensure even gasket compression. Torque to specification using a torque wrench.
    ℹ️Cross-pattern tightening prevents gasket distortion and ensures even sealing pressure.
    Torque spec

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

    Reinstall exhaust hanger
    If the exhaust hanger was removed, reinstall and torque the hanger bolts to specification. Ensure the exhaust system is properly supported and not under stress.
    Torque spec

    Hanger Bolts23 Nm (17 lb-ft)
12. 12

    Reinstall oxygen sensor
    If removed, reinstall the oxygen sensor with anti-seize applied only to the threads. Torque to specification and reconnect the electrical connector. Ensure the wiring is routed away from hot exhaust components.
    Torque spec

    O2 Sensor45 Nm (33 lb-ft)
13. 13

    Reinstall heat shields
    Reinstall all heat shields removed during disassembly. Torque mounting bolts to specification. Ensure shields are not touching any rotating components or wiring.
    Torque spec

    Heat Shield Bolts10 Nm (7 lb-ft)

Reassembly

1. Reconnect battery negative terminal if disconnected
2. Remove jack stands and lower vehicle to ground
3. Double-check all fasteners are tightened to specification
4. Verify oxygen sensor connector is fully seated and locked

Verification

• Start engine and listen for exhaust leaks at the front flange connection - there should be no hissing or ticking sounds
• Allow engine to reach operating temperature and recheck for leaks
• Visually inspect the flange connection for signs of exhaust gas escaping (soot marks)
• If equipped, verify no oxygen sensor diagnostic trouble codes are present using a scan tool
• Perform a test drive and listen for exhaust noise changes under acceleration

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