Complete replacement of all hydraulic roller finger followers (lifters/tappets) on the 3.5L EcoBoost twin-turbo V6 engine, requiring removal of both valve covers, camshafts, and timing components.

Warnings

Tools required

Parts

• Hydraulic roller finger followers (lifters) × 24 — DG1Z-6500-A or equivalent
• Left valve cover gasket kit × 1 — Use OEM specification
• Right valve cover gasket kit × 1 — Use OEM specification
• Timing cover gasket × 1 — Use OEM specification
• Camshaft position sensor O-rings × 4 — Use OEM specification
• Valve cover ignition coil grommets × 6 — Use OEM specification
• Engine oil and filter × 1 — FL-910S or equivalent
• RTV silicone sealant (Motorcraft TA-357) × 1 — TA-357

Fluids

• Motorcraft 5W-20 Synthetic Blend engine oil — 6 qt

Preparation

1. Park vehicle on level surface, engage parking brake, and place wheel chocks behind rear wheels
2. Disconnect negative battery cable and wait 10 minutes for airbag system to deplete
3. Allow engine to cool completely for minimum 2 hours to release fuel system pressure
4. Remove engine cover by pulling upward on front clips
5. Drain engine oil completely and remove oil filter
6. Remove air intake system including both air filter boxes and charge air cooler tubes
7. Disconnect PCV hoses and vacuum lines from both valve covers
8. Label and photograph all electrical connections, vacuum lines, and hose routing before disconnection
9. Install engine support bar across engine bay or attach engine hoist to lifting eyes
10. Support engine weight from above before removing upper motor mount
11. Set up clean workspace with labeled parts organizer trays for each cylinder bank

Procedure

1. 1

   Remove ignition coils and valve covers
   Disconnect all six ignition coil electrical connectors. Remove the mounting bolt from each coil and pull coils straight up from spark plug tubes. Remove the 13 bolts from each valve cover in reverse of tightening sequence (outside to inside). Carefully lift valve covers off, breaking seal with plastic wedge if needed. Do not pry against sealing surfaces.
   Torque spec

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

   Position engine at TDC cylinder #1
   Remove spark plug from cylinder #1 (front right cylinder on right bank). Insert long screwdriver or TDC finder into spark plug hole. Manually rotate crankshaft clockwise using 22mm socket on crankshaft pulley bolt until piston #1 reaches top of stroke. Verify timing marks on camshaft sprockets align with cylinder head surface and timing marks on crankshaft pulley align with timing cover pointer. This is CRITICAL - double-check all timing marks before proceeding.
   ⚠️If timing marks do not align perfectly, DO NOT proceed. Recheck crankshaft position. Incorrect TDC position will result in engine damage.
3. 3

   Remove accessory drive and timing cover
   Remove serpentine belt by rotating tensioner clockwise and slipping belt off pulleys. Remove crankshaft pulley bolt (requires breaker bar, bolt is very tight - approx 250 Nm). Remove pulley using puller if necessary. Remove all timing cover bolts (multiple sizes - organize by location). Remove water pump pulley if obstructing access. Carefully remove timing cover, noting RTV sealant locations.
   Torque spec

   Cover Bolts19 Nm (14 lb-ft)
4. 4

   Lock timing chain tensioners and mark timing
   Using timing chain tensioner compressor tool, compress both left and right bank primary tensioners and insert retaining pins or paper clips through locking holes. Mark timing chain to camshaft sprocket relationship with paint pen on all four camshaft sprockets (intake and exhaust, both banks). Take photos for reference. Mark chain link position relative to sprocket timing marks.
   ⚠️Tensioners MUST be locked before removing camshaft bolts. Chain tension will cause sprockets to rotate if tensioners are not locked.
5. 5

   Remove camshaft position sensors
   Disconnect electrical connectors from all four camshaft position sensors (intake and exhaust, both banks). Remove sensor mounting bolts and carefully withdraw sensors. Note O-ring condition and replace during reassembly. Set sensors aside in labeled containers to prevent mixing.
   Torque spec

   Camshaft Position Sensor10 Nm (7 lb-ft)
6. 6

   Remove right bank camshafts
   Starting with right cylinder bank (passenger side): Remove camshaft sprocket bolts while holding camshaft with holding tool. Mark sprockets LEFT/RIGHT and INTAKE/EXHAUST. Remove camshaft bearing cap bolts in reverse sequence (outside caps first, working toward center) in multiple passes, loosening 1-2 turns at a time to gradually release valve spring pressure. Remove bearing caps in order and label them with cylinder number and position. Carefully lift intake camshaft, then exhaust camshaft straight up. Place camshafts on clean surface with journals protected.
   ⚠️Bearing caps MUST be loosened gradually in multiple passes. Rapid removal can bend camshaft or crack bearing caps due to valve spring pressure.
   ⚠Bearing caps are NOT interchangeable and must be reinstalled in exact original positions and orientations.
   Torque spec

   Camshaft Bearing Cap Bolts14 Nm (10 lb-ft)
7. 7

   Remove right bank roller finger followers
   Using magnetic pickup tool or fingers, carefully remove all 12 roller finger followers from right bank. Each follower sits in its bore and can be lifted straight out. Place each follower in labeled compartment indicating exact cylinder number and intake/exhaust position. Inspect each follower bore for scoring or debris. Inspect each follower roller for flat spots, pitting, or roughness - replace any damaged followers. Clean all bores with lint-free cloth.
   ⚠Roller finger followers MUST NOT be mixed between positions. Each follower wears to its specific cam lobe and must return to same location or be replaced.
8. 8

   Remove left bank camshafts and followers
   Repeat steps 6 and 7 for left cylinder bank (driver side). Remove camshaft sprocket bolts, bearing cap bolts in sequence (multiple passes), bearing caps (labeled), camshafts, and all 12 roller finger followers. Keep left and right bank components completely separated in labeled containers.
   ⚠Left and right bank components are similar but NOT identical. Never mix components between banks.
   Torque spec

   Camshaft Bearing Cap Bolts14 Nm (10 lb-ft)
9. 9

   Inspect and measure components
   Inspect all 24 cam lobes on both camshafts for scoring, pitting, or wear. Measure lobe height with micrometer if wear is suspected (compare to specification). Inspect camshaft journals for scoring. Inspect all roller finger follower contact surfaces and rollers - replace any with pitting, flat spots, discoloration, or rough rotation. Inspect cylinder head valve spring retainer seats for damage. Clean all camshaft journal surfaces and bearing cap bores with clean lint-free cloths and brake cleaner.
   ℹ️EcoBoost engines are prone to cam phaser and follower wear. If significant wear is found, investigate oil change history and consider phaser replacement.
10. 10

    Install new right bank roller finger followers
    Pre-lubricate each new roller finger follower by coating with clean engine oil, ensuring roller and body are fully lubricated. Install each follower into its correct bore in right bank cylinder head. Followers should drop in easily but fit snugly without excessive side play. Verify each follower is fully seated in its bore and rotates freely. Install all 12 followers for right bank before proceeding.
    ⚠Inadequate pre-lubrication will cause immediate follower failure on startup. Each follower must be dripping with oil before installation.
11. 11

    Install right bank camshafts
    Liberally oil all camshaft journals and lobes with clean engine oil. Carefully lower exhaust camshaft into position, then intake camshaft, ensuring cam lobes do not contact followers during installation. Apply thin coat of clean engine oil to bearing cap journals. Install bearing caps in exact original positions with alignment arrows pointing toward front of engine. Hand-start all bearing cap bolts. Tighten bearing cap bolts in sequence from center outward in THREE passes: first pass 5 Nm, second pass 10 Nm, final pass 14 Nm. Verify camshafts rotate smoothly by hand.
    ⚠️Bearing cap bolt sequence and multi-pass torquing is CRITICAL. Single-pass torquing or incorrect sequence will warp caps and destroy engine. Follow exact sequence from service manual.
    Torque spec

    Camshaft Bearing Cap Bolts14 Nm (10 lb-ft)
12. 12

    Install left bank followers and camshafts
    Repeat steps 10 and 11 for left cylinder bank. Pre-lubricate and install all 12 new roller finger followers. Oil and install exhaust and intake camshafts. Install bearing caps in correct positions and orientations. Tighten bearing cap bolts in three passes from center outward to final torque of 14 Nm. Verify smooth camshaft rotation.
    Torque spec

    Camshaft Bearing Cap Bolts14 Nm (10 lb-ft)
13. 13

    Reinstall camshaft sprockets and verify timing
    Ensure crankshaft has not moved from TDC position. Install camshaft sprockets onto camshafts matching timing marks made during removal. Align chain marks with sprocket timing marks exactly as photographed. Install and hand-tighten sprocket bolts. Using camshaft holding tool to prevent rotation, torque sprocket bolts to specification (check service manual - typically 45-55 Nm for EcoBoost). Remove tensioner locking pins to apply chain tension. Manually rotate crankshaft two complete revolutions clockwise and verify all timing marks realign perfectly at TDC.
    ⚠️After rotating engine two revolutions, timing marks MUST align exactly. If marks are off by even one chain link, timing is incorrect - do not start engine. Remove sprockets and reinstall correctly.
14. 14

    Install camshaft position sensors
    Install new O-rings on all four camshaft position sensors, lubricating O-rings with clean engine oil. Insert sensors into cylinder heads and tighten mounting bolts to 10 Nm. Reconnect all sensor electrical connectors ensuring positive lock engagement.
    Torque spec

    Camshaft Position Sensor10 Nm (7 lb-ft)
15. 15

    Reinstall timing cover and valve covers
    Clean all gasket surfaces thoroughly with plastic scraper and brake cleaner. Apply small beads of RTV sealant at cylinder head-to-engine block corners where specified. Install new timing cover gasket and position timing cover, ensuring alignment dowels engage. Install and tighten cover bolts to 19 Nm. Install new valve cover gaskets and ignition coil grommets. Position valve covers and install bolts, tightening in sequence from center outward to 10 Nm. Install ignition coils with new grommets and tighten mounting bolts. Reinstall crankshaft pulley and torque bolt to specification (approximately 250 Nm). Install serpentine belt.
    Torque spec

    Cover Bolts19 Nm (14 lb-ft)

Reassembly

1. Reinstall all vacuum lines, PCV hoses, and electrical connections per photos taken during disassembly
2. Reinstall charge air cooler tubes and air intake system, ensuring all clamps are tight
3. Remove engine support and reinstall upper motor mount if removed
4. Install new oil filter and refill engine with 6 quarts Motorcraft 5W-20 synthetic blend oil
5. Reinstall engine cover
6. Reconnect negative battery cable

Verification

• Before starting engine, manually rotate crankshaft one complete revolution by hand to verify no binding or interference - should rotate smoothly
• Prime oil system by removing fuel pump fuse and cranking engine for 10 seconds in 5-second intervals until oil pressure gauge shows pressure
• Reinstall fuel pump fuse and start engine - should start immediately without unusual noises
• Monitor for oil leaks around valve covers and timing cover during first minute of operation
• Listen for any ticking, knocking, or unusual valve train noises - lifters may tick briefly during initial startup but should quiet within 30-60 seconds
• Allow engine to reach operating temperature and verify smooth idle with no misfires or fault codes
• Check engine oil level and top off if needed - level may drop slightly as new lifters fill with oil
• Test drive vehicle under light load and verify smooth acceleration, no hesitation, and proper power delivery
• Re-check all connections and torque critical fasteners after 50-100 miles of operation
• Monitor oil consumption and valve train noise over next 500 miles - new lifters require break-in period

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