Intake Manifold Gasket

This procedure covers the removal and replacement of the intake manifold gaskets on a 2015-2020 Ford F-150 with the 3.5L EcoBoost V6 engine, including removal of upper and lower intake manifolds.

Warnings

Tools required

Parts

• Lower intake manifold gasket set × 1 — Use OEM specification
• Upper intake manifold gasket × 1 — Use OEM specification
• Throttle body gasket × 1 — Use OEM specification
• PCV valve (if damaged) × 1 — Use OEM specification
• EGR valve gasket (if equipped) × 1 — Use OEM specification

Fluids

• Motorcraft Orange Coolant — 2 qt

Preparation

1. Ensure engine is completely cool to the touch
2. Park vehicle on level surface and engage parking brake
3. Disconnect negative battery cable and wait 5 minutes for capacitive discharge
4. Remove engine cover by pulling upward on front edge, then lifting away
5. Place drain pan under lower radiator hose and drain approximately 2 quarts of coolant
6. Relieve fuel system pressure by removing fuel pump fuse and attempting to start engine until it dies
7. Take photos of vacuum line routing and electrical connector locations for reference during reassembly

Procedure

1. 1

   Remove air intake system and throttle body
   Disconnect the mass airflow sensor electrical connector. Loosen the clamp at the air filter housing and turbocharger inlet, then remove the air intake tube. Disconnect the throttle body electrical connector. Remove the four throttle body mounting bolts and carefully lift the throttle body away from the upper intake manifold. Inspect the gasket surface for damage.
   Torque spec

   Throttle Body Bolts10 Nm (7 lb-ft)
2. 2

   Disconnect vacuum lines and PCV system
   Disconnect the brake booster vacuum line from the upper intake manifold. Disconnect all vacuum lines from the intake manifold, noting their positions. Remove the PCV hose from the valve cover to the intake manifold. If replacing the PCV valve, remove it from the valve cover at this time.
   ℹ️Label vacuum lines with tape if reference photos are unclear. Incorrect vacuum routing can cause driveability issues.
3. 3

   Remove fuel rail and injector harness
   Disconnect the fuel supply line from the fuel rail using the appropriate fuel line disconnect tool. Disconnect all fuel injector electrical connectors (six total). Remove the fuel rail mounting bolts. Carefully pull the fuel rail with injectors still attached straight up and away from the lower intake manifold. Place the fuel rail assembly aside in a safe location where injectors will not be damaged.
   ⚠Do not bend or kink fuel lines. Fuel injectors must be pulled straight out to avoid O-ring damage.
   Torque spec

   Fuel Rail Bolts12 Nm (9 lb-ft)
4. 4

   Disconnect coolant and EGR components
   Disconnect the coolant crossover hoses from the upper intake manifold. If equipped with EGR, disconnect the EGR valve electrical connector and remove the EGR valve mounting bolts. Remove the EGR valve and set aside with gasket. Disconnect any remaining coolant hoses connected to the intake manifold.
   ⚠Some coolant will drain from crossover hoses. Have towels ready to prevent spills onto engine components.
5. 5

   Remove upper intake manifold
   Disconnect any remaining electrical connectors attached to the upper intake manifold (EVAP purge valve, manifold pressure sensors, etc.). Remove all upper intake manifold mounting bolts. Note the location of any studs or brackets. Carefully lift the upper intake manifold away from the lower intake manifold. Inspect the gasket surface for damage or debris.
6. 6

   Remove lower intake manifold
   Disconnect any remaining electrical connectors or sensors on the lower intake manifold. Remove all lower intake manifold mounting bolts in reverse order of the tightening sequence (outside to center). Carefully lift the lower intake manifold away from the cylinder heads. The manifold may be adhered to the gaskets; gently work it loose if necessary.
   ⚠Do not pry between gasket surfaces. Use only the manifold edges to break the seal to avoid damaging sealing surfaces.
   Torque spec

   Intake Manifold Bolts25 Nm (18 lb-ft)
7. 7

   Remove and clean old gaskets
   Remove all old gasket material from the cylinder head surfaces and intake manifold mating surfaces. Use a plastic gasket scraper to avoid gouging aluminum surfaces. Clean all surfaces thoroughly with brake cleaner and lint-free towels. Inspect cylinder head and manifold surfaces for warping, cracks, or damage. Ensure all bolt holes are clean and free of debris or old thread sealant.
   ⚠Do not allow gasket material or debris to fall into cylinder head ports or coolant passages. Cover openings with clean towels during cleaning.
8. 8

   Install new lower intake manifold gaskets
   Position new lower intake manifold gaskets onto the cylinder heads. Ensure gaskets are properly aligned with all bolt holes and ports. Check that gaskets are seated in locating tabs or grooves if present. Do not use gasket sealant unless specifically called for by gasket manufacturer. Verify coolant and vacuum passages align correctly.
   ℹ️Some gasket sets include alignment pins or tabs. Ensure these are properly positioned before installing manifold.
9. 9

   Install lower intake manifold
   Carefully lower the lower intake manifold onto the cylinder heads, ensuring gaskets remain properly positioned. Start all intake manifold bolts by hand to ensure proper thread engagement. Tighten the intake manifold bolts to 25 Nm (18 lb-ft) in the proper sequence, working from the center bolts outward to the outer bolts. Perform the tightening sequence in at least two stages (50% torque, then final torque) for even gasket compression.
   ⚠Improper tightening sequence or over-torquing can warp the manifold or cause gasket failure. Follow center-out pattern strictly.
   Torque spec

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

    Install upper intake manifold
    Position the new upper intake manifold gasket. Carefully place the upper intake manifold onto the lower intake manifold, ensuring the gasket remains properly aligned. Install all mounting bolts and tighten the cover bolts to 19 Nm (14 lb-ft) in a cross-pattern sequence.
11. 11

    Reinstall EGR and coolant components
    If equipped with EGR, install a new EGR valve gasket and reinstall the EGR valve. Tighten the EGR valve bolts to 25 Nm (18 lb-ft). Reconnect the EGR electrical connector. Reinstall the coolant crossover lines and tighten crossover bolts to 15 Nm (11 lb-ft) if equipped with bolted connections. Reconnect all coolant hoses and secure with new clamps if originals are damaged.
12. 12

    Reinstall fuel rail and injectors
    Lubricate fuel injector O-rings with clean engine oil. Carefully position the fuel rail assembly with injectors over the injector ports in the lower intake manifold. Press the fuel rail down evenly to seat all six injectors simultaneously. Install and tighten the fuel rail bolts to 12 Nm (9 lb-ft). Reconnect all fuel injector electrical connectors. Reconnect the fuel supply line, ensuring it clicks securely into place.
    ⚠Ensure injectors are fully seated before tightening fuel rail bolts. Partially seated injectors can cause fuel leaks.
    Torque spec

    Fuel Rail Bolts12 Nm (9 lb-ft)
13. 13

    Reconnect vacuum and PCV systems
    Reconnect all vacuum lines to their original positions using reference photos. Ensure all connections are secure and hoses are not kinked. If replacing the PCV valve, install the new valve into the valve cover and tighten to 8 Nm (6 lb-ft). Reconnect the PCV hose between the valve cover and intake manifold. Reconnect the brake booster vacuum line.
14. 14

    Reinstall throttle body and air intake
    Install a new throttle body gasket onto the upper intake manifold. Position the throttle body and install all four mounting bolts. Tighten the throttle body bolts to 10 Nm (7 lb-ft) in a cross pattern. Reconnect the throttle body electrical connector. Reinstall the air intake tube and tighten clamps. Reconnect the mass airflow sensor electrical connector.
    Torque spec

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

    Final connections and refill coolant
    Reconnect all remaining electrical connectors, sensors, and components removed during disassembly. Verify all connections are secure. Reconnect the negative battery cable. Refill the cooling system with Motorcraft Orange Coolant to the proper level. Do not start the engine yet; allow coolant to settle and top off as needed.
    ℹ️The cooling system will need to be burped after initial startup to remove air pockets.

Reassembly

1. Double-check that all electrical connectors are properly seated and locked
2. Verify all vacuum lines are connected and not kinked or damaged
3. Ensure all tools and towels are removed from the engine compartment
4. Reinstall the engine cover by aligning the grommets and pressing down firmly

Verification

• Turn the ignition to the ON position without starting (key on, engine off) and listen for the fuel pump to prime. Check for fuel leaks around the fuel rail and connections
• Start the engine and allow it to idle. Monitor for unusual noises, rough idle, or warning lights
• Check for coolant leaks around the intake manifold and coolant crossover connections
• Check for vacuum leaks by listening for hissing sounds around the intake manifold and vacuum connections
• Allow the engine to reach operating temperature and verify the cooling fans cycle properly
• After the engine reaches operating temperature, turn it off and allow it to cool for 30 minutes. Recheck coolant level and top off if necessary
• Test drive the vehicle and verify normal acceleration, no hesitation, and no check engine light. Monitor coolant temperature during the drive
• After test drive, recheck all connections for leaks and verify torque on all accessible bolts

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