Replace a single valve spring on the 3.5L EcoBoost V6 engine by removing the valve cover, rotating the engine to position the valve, compressing the spring, and installing the new spring assembly.

Warnings

Tools required

Parts

• Valve spring assembly × 1 — Use OEM specification
• Valve cover gasket × 1 — Use OEM specification
• Valve stem seals (if replacing) × 1 — Use OEM specification
• Spark plug gaskets/seals × 1 — Use OEM specification

Preparation

1. Ensure engine is completely cool to the touch
2. Disconnect negative battery cable and wait 5 minutes for system capacitors to discharge
3. Remove engine cover by pulling upward on front clips and lifting off
4. Identify which cylinder (1-6) and which valve (intake or exhaust) requires spring replacement
5. Take photos of ignition coil and sensor connections for reference during reassembly
6. Clean the work area around the valve cover to prevent debris entry

Procedure

1. 1

   Remove ignition coils and spark plugs
   Disconnect electrical connectors from ignition coils on the affected cylinder bank. Remove coil mounting bolts and pull coils straight out. Remove spark plugs from cylinders, noting their condition. Focus on the cylinder requiring valve spring replacement but remove all plugs on that bank for access.
   Torque spec

   Electrical Connector Bolts8 Nm (6 lb-ft)

   Spark Plugs - Aluminum Head20 Nm (15 lb-ft)
2. 2

   Remove valve cover
   Disconnect any remaining electrical connectors, PCV hoses, and breather tubes from valve cover. Remove valve cover bolts in reverse of tightening sequence (outside to inside pattern). Carefully lift valve cover off, using gentle prying if needed at designated pry points only. Inspect gasket and mating surfaces.
   Torque spec

   Cover Bolts19 Nm (14 lb-ft)
3. 3

   Rotate engine to position valve
   Using a socket on the crankshaft pulley bolt, rotate the engine clockwise (viewed from front) until the camshaft lobe for the affected valve is pointing away from the valve (base circle position). This reduces spring pressure and prevents valve contact with piston. Verify piston is NOT at top dead center for this cylinder to allow valve movement room.
   ⚠Ensure transmission is in Park and parking brake is engaged before rotating engine
4. 4

   Remove rocker arm
   Remove the rocker arm bolt for the affected valve. Carefully lift the rocker arm off the valve stem and lash adjuster. Keep the roller finger follower and lash adjuster together if removed as a unit. Store in a clean container to prevent dirt contamination.
   Torque spec

   Rocker Arm Bolts30 Nm (22 lb-ft)
5. 5

   Compress valve spring and remove keepers
   Install valve spring compressor tool according to manufacturer instructions, ensuring proper seating on spring retainer. Slowly compress the spring until tension is released from valve keepers. Using magnetic pick-up tool, carefully remove both valve keepers (collets) from valve stem groove. Store keepers in a secure location.
   ⚠️Keep face and hands clear of spring compressor - sudden release can cause injury
   ⚠Do not over-compress spring or you may damage retainer or valve stem
6. 6

   Remove spring retainer and valve spring
   Slowly release tension on spring compressor tool. Remove the spring retainer (upper collar), valve spring, and spring seat (lower collar) from valve stem. If replacing valve stem seal, carefully remove old seal using appropriate seal removal tool. Inspect valve stem for scoring or damage.
7. 7

   Install new valve spring assembly
   If replacing valve stem seal, lubricate new seal with clean engine oil and carefully install onto valve guide using seal installation tool - do not hammer directly on seal. Install spring seat (lower collar) onto valve stem. Position new valve spring over valve stem with closer-wound coils toward cylinder head (if applicable). Install spring retainer (upper collar) on top of spring.
   ℹ️Verify spring orientation - some springs have variable pitch and must be installed correctly
8. 8

   Compress spring and install keepers
   Reinstall valve spring compressor and carefully compress new spring until groove in valve stem is exposed. Apply small amount of clean grease to inside of valve keepers to hold them in place. Carefully position both keepers in valve stem groove using magnetic tool or needle-nose pliers. Verify keepers are fully seated in groove around entire circumference.
   ⚠Keepers must be fully seated in stem groove before releasing spring tension
9. 9

   Release spring tension and verify installation
   Very slowly release valve spring compressor while watching keepers to ensure they remain seated. Once tension is released, remove compressor tool. Gently tap valve stem tip with plastic mallet to verify keepers are locked in place - spring should not move. Visually inspect keeper seating from all angles.
10. 10

    Reinstall rocker arm
    Verify camshaft lobe is still pointing away from valve (base circle). Position lash adjuster (if removed) back in its bore. Install rocker arm over valve stem and lash adjuster. Install and tighten rocker arm bolt to specification with cam lobe pointing away from valve.
    Torque spec

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

    Clean and install valve cover
    Thoroughly clean valve cover and cylinder head mating surfaces using razor blade or gasket scraper. Remove all old gasket material and oil residue. Wipe surfaces clean with solvent and lint-free towel. Install new valve cover gasket, ensuring proper seating in cover groove. Position valve cover onto cylinder head, aligning all bolt holes.
    Torque spec

    Gasket Surface Bolts23 Nm (17 lb-ft)
12. 12

    Torque valve cover bolts
    Install all valve cover bolts finger-tight. Tighten bolts in proper sequence (center outward pattern) to specification using torque wrench. Reconnect PCV hose, breather tube, and all electrical connectors to valve cover components.
    Torque spec

    Cover Bolts19 Nm (14 lb-ft)
13. 13

    Reinstall spark plugs and ignition coils
    Apply anti-seize compound to spark plug threads. Install spark plugs and torque to specification. Install ignition coils into spark plug tubes, ensuring proper seating. Install coil mounting bolts and torque electrical connector bolts to specification. Reconnect all ignition coil electrical connectors.
    Torque spec

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

    Electrical Connector Bolts8 Nm (6 lb-ft)

Reassembly

1. Reconnect negative battery cable
2. Reinstall engine cover by aligning clips and pressing down until seated
3. Verify all tools and parts have been removed from engine compartment
4. Double-check all electrical connections are fully seated and locked

Verification

• Start engine and listen for any unusual valve train noise or ticking from repaired cylinder
• Allow engine to idle for 2-3 minutes and monitor for oil leaks around valve cover
• Check for proper engine idle quality - rough idle may indicate valve seating issue
• Perform test drive and verify normal engine performance under light and moderate acceleration
• Re-check valve cover bolts for proper torque after engine reaches operating temperature and cools
• Scan for diagnostic trouble codes using OBD-II scanner to verify no misfires are present

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