This procedure adjusts the valve lash on the 2015-2020 Ford F-150 3.5L EcoBoost engine to maintain proper valve train clearances and ensure optimal engine performance.

Warnings

Tools required

Parts

• Valve cover gasket (left bank) × 1 — Use OEM specification
• Valve cover gasket (right bank) × 1 — Use OEM specification
• Spark plug tube seals × 6 — Use OEM specification

Preparation

1. Ensure engine is completely cold (has not run for at least 4 hours)
2. Disconnect negative battery cable and wait 5 minutes
3. Remove engine cover by pulling upward on front edge
4. Label and disconnect ignition coils from both valve covers
5. Remove ignition coils from all six cylinders
6. Disconnect any electrical connectors, vacuum lines, and PCV hoses attached to valve covers
7. On right bank, disconnect charge air cooler tube and move aside if needed for access

Procedure

1. 1

   Remove valve covers
   Remove valve cover bolts in reverse of tightening sequence (outside to inside pattern). Carefully lift valve covers off cylinder heads. If covers are stuck, gently tap with a rubber mallet. Do not pry against sealing surfaces.
   Torque spec

   Cover Bolts19 Nm (14 lb-ft)
2. 2

   Inspect valve train components
   Visually inspect rocker arms, valve tips, and camshaft lobes for wear, scoring, or damage. Check that all rocker arm bolts are secure. Replace any damaged components before proceeding with adjustment.
   ⚠If any valve train components show unusual wear or damage, investigate root cause before continuing.
3. 3

   Position crankshaft for cylinder 1
   Rotate crankshaft clockwise using 24mm socket on crankshaft bolt until cylinder 1 is at TDC (top dead center) on compression stroke. Both intake and exhaust valves for cylinder 1 should be closed (rocker arms should have play). Verify timing mark on crankshaft pulley aligns with pointer.
4. 4

   Check and adjust cylinder 1 valves
   Insert appropriate feeler gauge between rocker arm and valve tip for cylinder 1 intake valves. Gauge should slide with slight resistance. If clearance is incorrect, loosen valve lash adjusting screw lock nut while holding adjusting screw. Turn screw to achieve proper clearance, then hold screw while tightening lock nut. Recheck clearance after tightening. Repeat for cylinder 1 exhaust valves.
   ℹ️Target clearance: Intake 0.25mm (0.010 in), Exhaust 0.30mm (0.012 in) - aim for middle of specification range.
   Torque spec

   Valve Lash Adjusting Screw Lock Nut20 Nm (15 lb-ft)
5. 5

   Adjust remaining cylinders in firing order
   Using firing order 1-4-2-5-3-6, rotate crankshaft 120 degrees clockwise (1/3 turn) to position next cylinder at TDC compression stroke. Verify both valves are closed for that cylinder. Check and adjust valve lash as described in step 4. Continue rotating 120 degrees and adjusting until all six cylinders are completed.
   ⚠Always ensure cam lobes are pointing away from rocker arms (base circle) when adjusting. Both valves must be fully closed.
   Torque spec

   Valve Lash Adjusting Screw Lock Nut20 Nm (15 lb-ft)
6. 6

   Verify all adjustments
   Rotate crankshaft through two complete revolutions and recheck valve lash on all cylinders. All clearances should remain within specification. If any are out of specification, readjust as necessary.
7. 7

   Clean sealing surfaces
   Remove all old gasket material from valve cover and cylinder head sealing surfaces using gasket scraper. Be careful not to gouge aluminum surfaces. Clean surfaces thoroughly with isopropyl alcohol and allow to dry completely.
   ⚠Ensure no gasket material or debris falls into engine. Cover open valve train with clean shop towels during cleaning.
8. 8

   Install new valve cover gaskets
   Install new spark plug tube seals into valve cover. Position new valve cover gaskets onto valve covers, ensuring proper orientation and that all alignment features seat correctly. Do not use any sealant unless specified by manufacturer.
9. 9

   Install valve covers
   Carefully position valve covers onto cylinder heads, ensuring gaskets remain properly seated. Install valve cover bolts finger-tight initially. Tighten bolts in proper sequence (center outward in a crisscross pattern) using torque wrench to specification in two stages: first to 5 Nm, then final torque.
   Torque spec

   Cover Bolts19 Nm (14 lb-ft)
10. 10

    Reinstall ignition coils and connections
    Install ignition coils into spark plug tubes, ensuring they seat fully. Connect electrical connectors to each coil. Reconnect all vacuum lines, PCV hoses, and any other components removed during disassembly. Reinstall charge air cooler tube if removed. Install engine cover.

Reassembly

1. Reconnect negative battery cable
2. Before starting engine, verify all tools are removed from engine bay
3. All electrical connections, vacuum lines, and hoses must be properly reconnected
4. Double-check that valve cover bolts are torqued to specification

Verification

• Start engine and listen for abnormal valve train noise - properly adjusted valves should operate quietly
• Check for oil leaks around valve cover gaskets while engine is running
• Allow engine to reach operating temperature and verify smooth idle
• Road test vehicle and confirm normal performance with no misfires or rough running
• Recheck for valve cover leaks after test drive when engine is cool

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