This procedure covers removal and installation of the upper and lower intake manifolds on the 2015-2020 Ford F-150 3.5L EcoBoost V6 engine, including disconnection of fuel rails, sensors, and vacuum lines.

Warnings

Tools required

Parts

• Intake manifold gasket set × 1 — Use OEM specification
• Fuel rail O-rings × 6 — Use OEM specification
• Throttle body gasket × 1 — Use OEM specification
• PCV valve grommet (if damaged) × 1 — Use OEM specification

Preparation

1. Park vehicle on level surface and ensure engine is completely cold
2. Disconnect negative battery cable and wait 5 minutes for system capacitors to discharge
3. Remove engine cover by pulling upward on front and rear tabs
4. Relieve fuel system pressure by removing fuel pump fuse (location in power distribution box) and cranking engine until it stalls, then crank 5 more seconds
5. Place absorbent mat or drip pan under work area to catch any residual fuel
6. Photograph or label all vacuum lines, electrical connectors, and hose routing for reference during reinstallation

Procedure

1. 1

   Disconnect air intake system
   Loosen clamp at throttle body and disconnect air intake tube. Remove air filter housing if necessary for access. Disconnect mass airflow (MAF) sensor electrical connector. Remove complete air intake assembly and set aside.
2. 2

   Remove throttle body
   Disconnect throttle body electrical connector. Remove the four throttle body mounting bolts and carefully remove throttle body from upper intake manifold. Inspect throttle body gasket and discard. Cover throttle body opening with clean shop towel to prevent debris entry.
   ℹ️Do not force throttle plate open manually as this can damage the electronic throttle control system.
   Torque spec

   Throttle Body Bolts10 Nm (7 lb-ft)
3. 3

   Disconnect upper intake components
   Disconnect PCV hose from valve cover. Disconnect brake booster vacuum line from upper intake manifold. Disconnect all vacuum lines to EVAP purge valve, turbocharger wastegate actuators, and any other vacuum-operated components. Label each connection. Disconnect charge air cooler (intercooler) tubes from both sides of intake manifold and remove.
4. 4

   Remove upper intake manifold
   Disconnect any remaining electrical connectors on upper intake manifold (MAP sensor, etc.). Remove upper intake manifold mounting bolts in reverse of tightening sequence (outward from center). Carefully lift upper intake manifold away from lower manifold. Inspect and discard upper intake manifold gaskets. Cover lower intake manifold openings with clean shop towels.
   ⚠The upper intake manifold weighs approximately 15-20 lbs. Use care when lifting to avoid dropping onto engine components.
   Torque spec

   Intake Manifold Bolts25 Nm (18 lb-ft)
5. 5

   Disconnect fuel rails
   Disconnect fuel supply line from fuel rail using appropriate fuel line disconnect tool. Disconnect fuel return line if equipped. Disconnect all six fuel injector electrical connectors. Remove fuel rail mounting bolts. Carefully lift both fuel rails with injectors attached straight up and out of lower intake manifold. Cap or plug fuel rail openings immediately.
   ⚠️Even with pressure relieved, residual fuel will be present in fuel rails. Have absorbent rags ready and avoid skin contact with gasoline.
   ⚠Do not bend or kink fuel injectors during removal. Keep fuel rails and injectors together as an assembly.
   Torque spec

   Fuel Rail Bolts12 Nm (9 lb-ft)
6. 6

   Disconnect remaining sensors and hoses
   Disconnect coolant temperature sensor electrical connector. Disconnect knock sensors if attached to intake manifold. Remove PCV valve from valve cover by rotating counterclockwise. Disconnect any remaining vacuum lines or coolant hoses attached to lower intake manifold. Label all connections.
   ℹ️Some coolant may drain from hoses. Have drain pan ready if disconnecting coolant crossover passages.
7. 7

   Remove lower intake manifold
   Remove all lower intake manifold mounting bolts in reverse sequence (outward from center). Carefully break seal between manifold and cylinder heads by gently prying at designated pry points only (never between gasket surfaces). Lift lower intake manifold straight up and away from engine. Remove and discard all intake manifold gaskets.
   ⚠Do not pry between manifold and cylinder head gasket surfaces as this will cause damage requiring machining to repair.
   ℹ️The lower intake manifold is heavy and awkward. Consider having an assistant help with removal.
   Torque spec

   Intake Manifold Bolts25 Nm (18 lb-ft)
8. 8

   Clean gasket surfaces
   Thoroughly clean all gasket surfaces on cylinder heads and intake manifolds using plastic gasket scraper. Remove all old gasket material and sealant residue. Use shop vacuum to remove debris from intake ports and valley. Wipe surfaces clean with lint-free shop towels. Inspect cylinder head gasket surfaces for damage, warping, or corrosion.
   ⚠Never use metal scrapers or abrasive pads on aluminum gasket surfaces. Use only plastic or composite scraper tools.
   ⚠️Ensure no debris falls into cylinder head ports, turbochargers, or oil drain passages. Cover openings with clean towels during cleaning.
9. 9

   Install lower intake manifold
   Install new intake manifold gaskets onto cylinder heads, ensuring proper orientation and alignment with all ports. Carefully lower intake manifold into position, aligning all bolt holes. Install intake manifold bolts finger-tight. Tighten bolts to specification in proper sequence (center outward) using torque wrench. Verify sequence with factory service manual before tightening.
   ⚠Do not apply sealant to gaskets unless specifically called for by service manual. Most modern intake gaskets are dry-install only.
   ℹ️Ensure gaskets remain in position during manifold installation. Misaligned gaskets will cause vacuum leaks.
   Torque spec

   Intake Manifold Bolts25 Nm (18 lb-ft)
10. 10

    Reinstall sensors and hoses to lower manifold
    Reconnect coolant temperature sensor electrical connector. Reconnect knock sensors if removed. Install PCV valve into valve cover and tighten to specification. Reconnect any vacuum lines and coolant hoses to lower intake manifold per labels and photographs from disassembly.
    Torque spec

    PCV Valve8 Nm (6 lb-ft)
11. 11

    Reinstall fuel rails
    Install new O-rings on all fuel injectors (lightly lubricate with clean engine oil). Carefully align fuel injectors with ports in lower intake manifold. Press fuel rails and injectors straight down into manifold until fully seated. Install fuel rail mounting bolts and tighten to specification in proper sequence per service manual. Reconnect all six fuel injector electrical connectors. Reconnect fuel supply and return lines, ensuring positive click engagement.
    ⚠Fuel injectors must be pressed straight down without twisting to prevent O-ring damage and fuel leaks.
    Torque spec

    Fuel Rail Bolts12 Nm (9 lb-ft)
12. 12

    Install upper intake manifold
    Install new upper intake manifold gaskets onto lower manifold. Position upper intake manifold and align with all mounting holes. Install upper intake manifold bolts finger-tight. Tighten bolts to specification in proper sequence (center outward) per service manual. Reconnect MAP sensor and any other electrical connectors on upper manifold.
    Torque spec

    Intake Manifold Bolts25 Nm (18 lb-ft)
13. 13

    Reconnect upper intake components
    Reconnect charge air cooler tubes to both sides of intake manifold and secure with clamps. Reconnect brake booster vacuum line. Reconnect PCV hose to valve cover. Reconnect all vacuum lines to EVAP purge valve, turbocharger wastegate actuators, and other vacuum components per labels from disassembly. Ensure all connections are secure.
14. 14

    Install throttle body
    Install new throttle body gasket onto upper intake manifold. Position throttle body and install mounting bolts finger-tight. Tighten throttle body bolts to specification in cross pattern. Reconnect throttle body electrical connector.
    Torque spec

    Throttle Body Bolts10 Nm (7 lb-ft)
15. 15

    Reinstall air intake system
    Reinstall air filter housing if removed. Reconnect mass airflow sensor electrical connector. Install air intake tube to throttle body and tighten clamp securely. Reconnect negative battery cable. Reinstall engine cover.

Reassembly

1. Double-check that all electrical connectors, vacuum lines, and hoses are properly connected
2. Verify all bolts are tightened to proper torque specifications
3. Ensure no tools or rags were left in engine compartment
4. Reinstall fuel pump fuse that was removed during pressure relief procedure

Verification

• Turn ignition to ON position (do not start) and listen for fuel pump priming. Check for fuel leaks around fuel rails and connections
• Start engine and allow to idle. Listen for abnormal vacuum leaks (hissing sounds)
• Monitor engine for smooth idle. Rough idle or check engine light may indicate vacuum leak or disconnected sensor
• Check for fuel odor around engine compartment. Any fuel smell indicates leak that must be corrected immediately
• Allow engine to reach operating temperature and verify no coolant leaks if coolant hoses were disconnected
• Test drive vehicle and verify normal acceleration, boost pressure, and absence of check engine light
• Scan for diagnostic trouble codes after test drive to confirm all sensors are functioning properly

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