Intake Manifold Gasket

This procedure replaces the intake manifold gaskets on the 3.5L EcoBoost V6 engine, requiring removal of the intake manifold, fuel rails, and various engine accessories to access and replace the gaskets.

Warnings

Tools required

Parts

• Intake manifold gasket set × 1 — Use OEM specification Ford/Motorcraft
• Throttle body gasket × 1 — Use OEM specification
• PCV valve grommet × 1 — Use OEM specification
• EGR valve gasket (if equipped) × 1 — Use OEM specification
• Fuel injector O-rings × 6 — Use OEM specification
• Coolant (replacement for spillage) × 1 — Motorcraft Orange Coolant

Fluids

• Motorcraft Orange Coolant — 2 qt

Preparation

1. Ensure engine is completely cool to the touch (minimum 2 hours after last operation)
2. Disconnect negative battery cable and wait 10 minutes for airbag system to discharge
3. Remove engine cover by pulling upward on front clips and lifting off
4. Place drain pan under radiator and drain approximately 2 quarts of coolant from petcock
5. Relieve fuel system pressure by removing fuel pump fuse, starting engine, and allowing it to stall
6. Label all electrical connectors and vacuum hoses with tape for proper reassembly

Procedure

1. 1

   Remove Air Intake System
   Disconnect the mass airflow sensor electrical connector. Loosen the clamp at the throttle body and turbocharger inlet. Remove the air intake tube assembly. Remove the air filter housing by disconnecting any mounting brackets and lifting it out of the engine bay.
2. 2

   Disconnect Throttle Body and Accessories
   Disconnect the throttle body electrical connector. Remove the throttle body coolant hoses (be prepared for coolant spillage). Disconnect the brake booster vacuum hose from the intake manifold. Disconnect the PCV hose and any evaporative emission hoses connected to the intake manifold.
   ⚠Have shop towels ready as coolant will drain from throttle body coolant hoses.
3. 3

   Remove Throttle Body
   Remove the four throttle body mounting bolts. Carefully pull the throttle body away from the intake manifold and set aside. Inspect the gasket and discard it.
   Torque spec

   Throttle Body Bolts10 Nm (7 lb-ft)
4. 4

   Disconnect Fuel System
   Disconnect the fuel supply line from the fuel rail using appropriate fuel line disconnect tools. Use shop towels to catch any residual fuel. Disconnect all fuel injector electrical connectors (6 total). Label each connector position if not already keyed.
   ⚠Even with pressure relieved, residual fuel will be present. Have towels ready and avoid open flames.
5. 5

   Remove Fuel Rails
   Remove the four fuel rail mounting bolts (two per rail). Carefully pull the fuel rails with injectors straight up and out of the intake manifold. Rock gently if needed but do not pry. Place fuel rails in a clean area and cover to prevent contamination.
   Torque spec

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

   Remove EGR Valve (If Equipped)
   Disconnect the EGR valve electrical connector. Remove the EGR valve coolant hoses if present. Remove the EGR valve mounting bolts and remove the EGR valve and gasket from the intake manifold. Cap any open coolant ports.
7. 7

   Disconnect Remaining Hoses and Wiring
   Disconnect any remaining vacuum hoses from the intake manifold, including purge valve connections. Disconnect the charge air cooler (intercooler) outlet tube from the intake manifold. Remove any wire harness brackets attached to the intake manifold. Disconnect the intake manifold runner control valve electrical connector if equipped.
8. 8

   Remove PCV Valve
   Remove the PCV valve from the driver side valve cover by rotating counterclockwise. Note the installed depth and orientation. Remove and discard the PCV valve grommet from the valve cover.
9. 9

   Remove Intake Manifold
   Remove all intake manifold mounting bolts in reverse of the tightening sequence (outside to center pattern). There are typically 8-10 bolts securing the manifold. Carefully lift the intake manifold straight up off the cylinder heads. If stuck, gently tap with a rubber mallet but do not pry between gasket surfaces.
   ⚠Do not pry between aluminum mating surfaces as this will cause damage requiring professional machining.
   Torque spec

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

    Remove Old Gaskets and Clean Surfaces
    Remove and discard all old intake manifold gaskets from both the manifold and cylinder head surfaces. Use a plastic scraper to carefully remove all gasket material without scratching aluminum surfaces. Clean surfaces with brake cleaner and lint-free shop towels. Inspect for any cracks or damage. Ensure all bolt holes are clean and free of debris or coolant.
    ⚠Do not use metal scrapers or wire brushes on aluminum surfaces. Use only plastic scrapers or non-metallic brushes.
11. 11

    Install New Gaskets and Position Intake Manifold
    Install new intake manifold gaskets onto the cylinder heads, ensuring proper orientation and alignment with all ports. The gaskets should have locating tabs or features. Carefully lower the intake manifold into position, ensuring gaskets remain properly seated. Align all bolt holes.
12. 12

    Torque Intake Manifold Bolts
    Install all intake manifold bolts finger-tight. Using a torque wrench, tighten the bolts to specification in the proper sequence (center outward in a spiral pattern). Consult a factory service manual diagram for the exact sequence. Make two passes: first to 12 Nm (9 lb-ft), then final torque to specification.
    ⚠Following the correct tightening sequence is critical to prevent vacuum leaks and ensure even gasket compression.
    Torque spec

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

    Install PCV Valve and EGR Valve
    Install new PCV valve grommet into the valve cover. Install the PCV valve into the grommet and valve cover, torquing to specification. Install EGR valve with new gasket and torque bolts to specification. Reconnect EGR coolant hoses if equipped.
14. 14

    Install Fuel Rails and Injectors
    Lubricate new fuel injector O-rings with clean engine oil. Install new O-rings on all six fuel injectors. Carefully insert fuel injectors into intake manifold ports, ensuring they seat fully. Install fuel rails and torque mounting bolts to specification. Reconnect all fuel injector electrical connectors.
    Torque spec

    Fuel Rail Bolts12 Nm (9 lb-ft)
15. 15

    Install Throttle Body and Reconnect Systems
    Install throttle body with new gasket and torque bolts to specification. Reconnect throttle body coolant hoses and electrical connector. Reconnect fuel supply line until it clicks into place. Reconnect brake booster vacuum hose, PCV hose, and all other vacuum and emission hoses per labels. Reconnect charge air cooler outlet tube.
    Torque spec

    Throttle Body Bolts10 Nm (7 lb-ft)
16. 16

    Reinstall Air Intake System
    Reinstall air filter housing and secure mounting brackets. Install air intake tube and tighten clamps at throttle body and turbocharger inlet. Reconnect mass airflow sensor electrical connector. Reinstall engine cover.

Reassembly

1. Refill cooling system with Motorcraft Orange Coolant to proper level
2. Reconnect negative battery cable
3. Reinstall fuel pump fuse
4. Prime fuel system by cycling ignition on/off three times without starting
5. Double-check all electrical connectors, hoses, and fasteners are properly connected

Verification

• Start engine and check for fuel leaks at fuel rail connections
• Check for coolant leaks at throttle body and EGR valve connections
• Check for vacuum leaks by listening for hissing sounds around intake manifold
• Verify idle quality is smooth with no rough running or misfires
• Allow engine to reach operating temperature and verify no coolant loss
• Perform a test drive to verify normal acceleration and boost pressure
• Scan for diagnostic trouble codes and verify none are present
• Recheck coolant level after test drive and top off if necessary

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