This procedure covers replacement of a single valve spring on the 3.5L EcoBoost V6 engine, requiring removal of the valve cover, rocker arm, and use of a valve spring compressor while maintaining engine timing.

Warnings

Tools required

Parts

• Valve spring (single) × 1 — Use OEM Ford specification
• Valve cover gasket × 1 — Use OEM Ford specification
• Spark plug tube seal (if applicable to affected cylinder) × 1 — Use OEM Ford specification
• Valve stem seals (if replacing) × 1 — Use OEM Ford specification

Fluids

• Motorcraft 0W-20 Full Synthetic — 0.5 qt

Preparation

1. Park vehicle on level surface and engage parking brake
2. Disconnect negative battery cable and wait 2 minutes for airbag system to discharge
3. Remove engine cover by pulling upward on retaining clips
4. Identify which cylinder requires valve spring replacement and determine bank location (driver side Bank 1 or passenger side Bank 2)
5. Allow engine to cool completely to ambient temperature (minimum 3 hours after last operation)
6. Remove ignition coil from affected cylinder by disconnecting electrical connector and removing mounting bolt
7. Remove any interfering components for valve cover access (air intake tubes, wiring harnesses, PCV hoses as needed)

Procedure

1. 1

   Remove spark plug from affected cylinder
   Using a 16mm spark plug socket, carefully remove the spark plug from the cylinder requiring valve spring service. Inspect plug condition and threads. This allows access for pressurizing the cylinder to hold valves in place during spring removal.
2. 2

   Remove valve cover
   Disconnect all electrical connectors and hoses attached to the valve cover. Remove valve cover bolts in reverse of tightening sequence (start from ends, work toward center). Carefully lift valve cover away from cylinder head. If stuck, gently tap with plastic mallet - do not pry against sealing surfaces.
   ⚠PCV and oil separator hoses may contain residual oil. Have shop towels ready.
3. 3

   Rotate engine to position affected cylinder
   Rotate the crankshaft clockwise using a socket on the crankshaft bolt until the cam lobes for the affected valve are pointing away from the valve (base circle position). This is essential for rocker arm removal. Verify timing marks are visible and mark cam position with paint pen before proceeding.
   ⚠Only rotate engine in the normal direction of rotation (clockwise from front). Never rotate counterclockwise.
4. 4

   Remove rocker arm from affected valve
   With cam lobe pointing away from valve, remove the rocker arm mounting bolt from the affected valve. Carefully lift rocker arm straight up and out. Inspect roller surface for wear. Note the rocker arm orientation and position for reinstallation.
   ℹ️Keep rocker arm and bolt together if reusing. Do not mix components between cylinders.
5. 5

   Pressurize cylinder to hold valves
   Install compressed air adapter into spark plug hole and apply 90-100 PSI of shop air pressure, OR feed approximately 3 feet of nylon rope into the cylinder through spark plug hole while rotating engine to bring piston near TDC on compression stroke. The air pressure or rope will prevent valves from dropping into cylinder during spring removal.
   ⚠️Maintain constant air pressure throughout spring removal. Loss of pressure may allow valve to drop into cylinder.
6. 6

   Remove valve spring keepers and retainer
   Position valve spring compressor tool over affected valve spring. Carefully compress the spring just enough to access the valve keepers (collets). Using a magnetic pick-up tool or small screwdriver, carefully remove both valve spring keepers. Slowly release spring compressor tension and remove retainer and spring. Keep all components organized.
   ⚠️Valve keepers are small and easily lost. Work over a clean cloth to catch keepers if dropped. Do not lose keepers into engine valley.
   ⚠Ensure valve spring compressor is properly seated before applying compression to prevent tool slippage.
7. 7

   Inspect and replace valve spring
   Remove the old valve spring and inspect valve stem seal. If seal shows damage or excessive wear, replace it now using appropriate seal installation tool. Clean valve spring seat area on cylinder head. Install new valve spring in correct orientation (closer wound coils typically face cylinder head). Verify spring sits flat on head surface.
   ℹ️Some valve springs are directional. Check service manual or spring markings for proper installation orientation.
8. 8

   Install retainer and keepers
   Place valve spring retainer over valve stem. Using valve spring compressor, compress new spring until keeper grooves on valve stem are fully visible and accessible. Carefully install both valve keepers into the valve stem grooves using magnetic pick-up tool or small screwdriver. Ensure keepers are fully seated in grooves on both sides. Slowly release spring compressor and verify keepers are locked in place and retainer is secure.
   ⚠️Tap valve stem lightly with plastic tool after releasing compressor to ensure keepers are fully seated. Improperly seated keepers will allow valve to drop during operation causing catastrophic engine damage.
9. 9

   Remove cylinder pressurization and test valve
   Remove air pressure fitting or pull rope out of cylinder through spark plug hole. Gently press down on valve spring retainer to verify valve movement is free and spring returns properly. Manually verify valve operation is smooth without binding.
10. 10

    Reinstall rocker arm
    Verify cam lobe is still pointing away from valve (base circle position). Apply small amount of clean engine oil to rocker arm roller and valve stem tip. Position rocker arm over valve and cam lobe. Install rocker arm bolt and tighten to specification. Manually rotate engine two complete revolutions and verify smooth operation without unusual noises.
    ⚠Cam lobe must be on base circle (pointing away from valve) during rocker arm bolt tightening to prevent valve train damage.
    Torque spec

    Rocker Arm Bolts30 Nm (22 lb-ft)
11. 11

    Clean and install valve cover
    Thoroughly clean valve cover and cylinder head gasket mating surfaces using razor blade or gasket scraper. Remove all old gasket material and oil residue. Wipe surfaces clean with brake cleaner and lint-free cloth. Install new valve cover gasket into valve cover groove, ensuring it seats properly around all bolt holes. Position valve cover onto cylinder head, aligning all bolt holes. Install valve cover bolts finger-tight, then torque in proper sequence (center outward) to specification.
    ℹ️Do not reuse valve cover gasket. Always install new gasket to prevent oil leaks.
    Torque spec

    Cover Bolts19 Nm (14 lb-ft)
12. 12

    Reinstall spark plug and ignition coil
    Apply small amount of anti-seize compound to spark plug threads (avoid electrode area). Install spark plug and torque to specification using 16mm spark plug socket. Reinstall ignition coil, connect electrical connector, and install coil mounting bolt.
    Torque spec

    Spark Plugs - Aluminum Head20 Nm (15 lb-ft)
13. 13

    Reinstall remaining components
    Reconnect all vacuum hoses, PCV hoses, and electrical connectors that were removed for valve cover access. Reinstall air intake components, wiring harnesses, and any other components removed during disassembly. Ensure all connections are secure and properly routed. Reconnect negative battery cable.

Reassembly

1. Double-check all electrical connectors are properly seated and locked
2. Verify all hoses are connected and routed correctly without kinks or interference
3. Confirm valve cover bolts are torqued in proper sequence to prevent oil leaks
4. Check that no tools or parts were left in engine compartment

Verification

• Start engine and allow to idle for 2-3 minutes while monitoring for unusual noises, particularly valve train ticking or tapping
• Check for oil leaks around valve cover gasket perimeter
• Verify smooth idle with no misfires on repaired cylinder (check for engine codes with scan tool)
• Rev engine to 2500 RPM briefly and listen for any abnormal valve train noise
• After 10 minutes of operation, recheck valve cover bolt torque if accessible
• Test drive vehicle under light load and verify normal performance without hesitation or rough running

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