Valve Cover Gasket - Single

This procedure covers the replacement of a single valve cover gasket on the 3.5L EcoBoost V6 engine to resolve oil leaks from the valve cover mating surface.

Warnings

Tools required

Parts

• Valve cover gasket kit × 1 — Use OEM specification
• Spark plug tube seals × 3 — Usually included in gasket kit
• Anti-seize compound × 1 — For spark plug threads

Preparation

1. Ensure engine is completely cool to the touch
2. Disconnect negative battery terminal and wait 2 minutes for system power down
3. Identify which valve cover requires replacement (passenger side or driver side)
4. Remove engine cover by pulling upward on clip locations
5. Photograph electrical connector and vacuum hose routing for reference during reassembly

Procedure

1. 1

   Remove ignition coils
   Disconnect the electrical connectors from each ignition coil on the affected bank by pressing the release tab and pulling straight up. Remove the ignition coil mounting bolts and carefully pull each coil straight out of the spark plug tube. Mark or photograph coil positions if they are not identical.
2. 2

   Remove spark plugs
   Using a 16mm spark plug socket with extension, carefully remove all three spark plugs from the affected cylinder bank. Inspect spark plugs for oil fouling which would indicate the gasket has been leaking for some time. Keep spark plugs in order if you plan to reinstall them.
   ⚠Debris falling into spark plug holes can cause severe engine damage. Keep the area clean and cover open holes with clean shop towels.
3. 3

   Disconnect electrical connectors and sensors
   Disconnect all electrical connectors attached to or crossing the valve cover. This typically includes cam position sensor connectors, variable valve timing solenoid connectors, and any wiring harness clips. Remove any sensor mounting bolts if sensors must be moved aside for access.
4. 4

   Remove PCV and vacuum connections
   Disconnect the PCV hose and any vacuum lines connected to the valve cover. On the 3.5L EcoBoost, the PCV system may include quick-disconnect fittings - press the release collar and pull straight out. Note routing for reinstallation.
5. 5

   Remove valve cover bolts
   Remove all valve cover bolts in a crisscross pattern starting from the outside and working inward. There are typically 11 bolts per valve cover on the 3.5L EcoBoost. Keep bolts organized as some may be different lengths.
   ℹ️Valve cover bolts should be removed gradually in reverse of tightening sequence to prevent warping.
   Torque spec

   Valve Cover Bolts10 Nm (7 lb-ft)
6. 6

   Remove valve cover
   Gently tap the valve cover with a rubber mallet to break the gasket seal. Carefully lift the valve cover straight up and away from the cylinder head. If the cover is stuck, tap gently in multiple locations but never pry with metal tools against the aluminum mating surfaces.
   ⚠Do not bend or distort the valve cover during removal as this will prevent proper sealing during reinstallation.
7. 7

   Remove old spark plug tube seals
   Carefully extract the old spark plug tube seals from the valve cover. These are press-fit rubber seals that may require gentle prying with a small pick or screwdriver. Also remove the old valve cover gasket completely from both the cover and cylinder head.
   Torque spec

   Spark Plug Tube Seals12 Nm (9 lb-ft)
8. 8

   Clean all mating surfaces
   Thoroughly clean the valve cover and cylinder head gasket mating surfaces using a plastic scraper and brake cleaner. Remove all traces of old gasket material and oil residue. The surfaces must be completely clean and dry for proper gasket sealing. Inspect for any damage, warping, or corrosion.
   ⚠Do not use metal scrapers or abrasive pads on aluminum surfaces. Any scratches or gouges will create leak paths.
9. 9

   Install new spark plug tube seals
   Press the new spark plug tube seals into the valve cover by hand until fully seated. The seals should sit flush with the valve cover surface. Apply a light coat of clean engine oil to the seal outer diameter to aid installation and prevent damage.
   ℹ️Ensure seals are fully seated and not cocked at an angle. Improperly seated seals will leak oil into spark plug wells.
   Torque spec

   Spark Plug Tube Seals12 Nm (9 lb-ft)
10. 10

    Install new valve cover gasket
    Position the new valve cover gasket onto the valve cover. Most gaskets have alignment features or clips that hold them in place. Ensure the gasket is properly seated in the valve cover groove with no twists or folds. Do not use any sealant unless specifically required by the gasket manufacturer.
11. 11

    Install valve cover
    Carefully position the valve cover with new gasket onto the cylinder head, ensuring the spark plug tube seals align with their corresponding holes. Start all valve cover bolts by hand to ensure proper thread engagement and cover alignment before tightening any bolts.
    ⚠Verify that the gasket remains properly positioned during installation and does not shift or pinch.
12. 12

    Torque valve cover bolts
    Tighten the valve cover bolts in the proper sequence (typically starting from the center and working outward in a crisscross pattern) to the specified torque of 10 Nm (7 lb-ft). Use a torque wrench and tighten gradually in multiple passes, going to 50% torque on the first pass and final torque on the second pass.
    ⚠Over-tightening valve cover bolts can crush the gasket, warp the cover, or strip threads. Always use a calibrated torque wrench.
    Torque spec

    Valve Cover Bolts10 Nm (7 lb-ft)
13. 13

    Reinstall spark plugs
    Apply a small amount of anti-seize compound to the spark plug threads (avoid getting any on the electrode). Thread each spark plug in by hand to prevent cross-threading, then torque to 20 Nm (15 lb-ft) using a torque wrench and spark plug socket.
    ⚠Cross-threaded spark plugs in aluminum heads can cause catastrophic and expensive damage. Always start by hand.
14. 14

    Reinstall ignition coils
    Apply a thin coat of dielectric grease to the inside of each ignition coil boot. Press each ignition coil firmly into its spark plug tube until fully seated. Install and torque the ignition coil mounting bolts to 8 Nm (6 lb-ft). Reconnect all ignition coil electrical connectors until they click into place.
15. 15

    Reconnect all components
    Reinstall any sensors removed during disassembly, torquing sensor mounting bolts to 12 Nm (9 lb-ft) and electrical connector bolts to 8 Nm (6 lb-ft). Reconnect all vacuum hoses, PCV connections, and wiring harness clips according to your reference photos. Reinstall the engine cover.

Reassembly

1. Reconnect the negative battery terminal
2. Double-check that all electrical connectors are fully seated and locked
3. Verify all vacuum hoses and PCV connections are secure
4. Ensure no tools or rags were left in the engine compartment

Verification

• Start the engine and listen for any vacuum leaks or unusual noises from the valve cover area
• Allow engine to reach normal operating temperature and inspect the valve cover gasket area for any signs of oil seepage
• Check for proper engine idle quality and verify no misfire codes are present
• After 50-100 miles of driving, re-inspect the valve cover gasket area when engine is cool to confirm no leaks have developed
• Monitor oil level and consumption over the next few oil change intervals to ensure the leak has been resolved

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