Exhaust Gasket - Front

Replace the front exhaust manifold gaskets on the 5.0L Coyote V8 engine, including removal of exhaust manifolds and associated components.

Warnings

Tools required

Parts

• Exhaust manifold gasket set (both sides) × 1 — Use OEM Motorcraft specification
• Exhaust manifold flange nuts × 16 — Recommend replacement if corroded

Preparation

1. Park vehicle on level surface and engage parking brake
2. Place wheel chocks behind rear wheels
3. Ensure engine is completely cool (minimum 2 hours after running)
4. Raise front of vehicle with floor jack and support securely on jack stands at frame rails
5. Spray all exhaust flange bolts and O2 sensors with penetrating oil if corrosion is present
6. Disconnect negative battery terminal

Procedure

1. 1

   Remove heat shields
   Locate and remove the exhaust manifold heat shields on both sides. Remove the bolts securing the heat shields to the cylinder heads. Set shields and hardware aside.
   Torque spec

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

   Disconnect oxygen sensors
   Locate the upstream O2 sensors on each exhaust manifold. Disconnect the electrical connectors by pressing the release tab. Using an O2 sensor socket or 22mm wrench, carefully unthread the sensors counterclockwise. Keep sensors organized by side if reusing.
   ⚠Do not let O2 sensors hang by wiring harness. Support sensor weight during removal.
   Torque spec

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

   Remove exhaust Y-pipe connection
   From underneath vehicle, locate where both exhaust manifolds connect to the Y-pipe/catalytic converter assembly. Remove the flange bolts connecting each manifold to the downstream exhaust. There are typically 4 bolts per side at this connection. Support the Y-pipe with a jack or wire to prevent it from dropping.
   Torque spec

   Exhaust Flange Bolts45 Nm (33 lb-ft)
4. 4

   Remove driver side exhaust manifold
   Working from the engine bay, locate the 8 exhaust manifold flange nuts securing the manifold to the cylinder head. Remove all nuts using a socket and extension. Carefully remove the manifold and old gasket. If manifold is stuck, gently tap with a rubber mallet to break the seal.
   ⚠If studs break during removal, they must be extracted before reassembly. Consider professional assistance if multiple studs break.
   Torque spec

   Exhaust Flange Bolts45 Nm (33 lb-ft)
5. 5

   Remove passenger side exhaust manifold
   Repeat the process for the passenger side manifold. Remove all 8 flange nuts and carefully remove the manifold and old gasket. Note that access may be tighter on passenger side due to steering components.
   Torque spec

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

   Clean mating surfaces
   Using a gasket scraper and wire brush, thoroughly clean all gasket material from both the cylinder head mating surfaces and the exhaust manifold flanges. Ensure surfaces are completely clean and flat with no carbon buildup, old gasket material, or debris. Wipe clean with shop towels.
   ⚠Do not gouge or scratch the cylinder head sealing surface. Damaged surfaces will cause exhaust leaks.
7. 7

   Inspect manifolds and studs
   Inspect exhaust manifolds for cracks, warping, or damage. Check all cylinder head studs for damage or excessive corrosion. Replace damaged components as needed. If studs are heavily corroded, run a thread chaser over them to clean threads.
   ℹ️5.0L Coyote manifolds are prone to cracking. Carefully inspect entire manifold surface, especially around port dividers.
8. 8

   Install new gaskets and driver side manifold
   Position new exhaust gasket onto the driver side cylinder head studs. Apply anti-seize compound to the threads of all flange nuts. Carefully position the exhaust manifold over the gasket and onto the studs. Thread all 8 nuts hand-tight, then torque in a spiral pattern from center outward to specification.
   ℹ️Torque in multiple passes: first to 50%, then to 100% specification to ensure even gasket compression.
   Torque spec

   Exhaust Flange Bolts45 Nm (33 lb-ft)
9. 9

   Install passenger side manifold
   Position new exhaust gasket onto the passenger side cylinder head studs. Apply anti-seize compound to flange nut threads. Install the manifold over the gasket and torque all 8 nuts in a spiral pattern from center outward to specification, using multiple passes.
   Torque spec

   Exhaust Flange Bolts45 Nm (33 lb-ft)
10. 10

    Reconnect Y-pipe to manifolds
    Raise the Y-pipe/catalytic converter assembly into position. Install new flange gaskets if available. Apply anti-seize to flange bolt threads. Install and torque the flange bolts connecting both manifolds to the downstream exhaust system.
    Torque spec

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

    Install oxygen sensors
    Apply a thin coat of anti-seize compound to the O2 sensor threads only, keeping anti-seize away from the sensor tip. Thread each O2 sensor into its manifold bung hand-tight, then torque to specification. Reconnect the electrical connectors ensuring they click into place.
    ⚠Do not get anti-seize on the O2 sensor tip or in the threads beyond the first few. Contamination will damage the sensor.
    Torque spec

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

    Reinstall heat shields
    Position the heat shields over the exhaust manifolds and install the mounting bolts. Torque heat shield bolts to specification. Ensure shields are properly positioned and not contacting any moving components or wiring.
    Torque spec

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

    Final inspection and lower vehicle
    Inspect all connections to ensure proper installation. Verify all fasteners are torqued and no tools or parts remain in engine bay. Reconnect negative battery terminal. Lower vehicle from jack stands safely.

Reassembly

1. Verify all exhaust connections are secure and properly torqued
2. Ensure heat shields are properly positioned and not contacting other components
3. Confirm all O2 sensor electrical connectors are fully seated
4. Check that no tools or parts remain in engine compartment or under vehicle

Verification

• Start engine and allow to idle, listening for exhaust leaks at manifold connections
• Inspect all manifold flange areas while engine is running for visible exhaust gas escape
• Allow engine to reach operating temperature and verify no leaks develop when hot
• Rev engine to 2000-2500 RPM and verify no exhaust noise or manifold gasket leaks
• Check for any check engine lights or O2 sensor codes after test drive
• Perform a brief test drive and recheck all connections for leaks after engine has fully heat cycled

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