Complete removal and replacement of one or both cylinder heads on the 3.5L EcoBoost V6, including turbocharger removal, timing chain service, and head bolt replacement.

Warnings

Tools required

Parts

• Cylinder head gasket (left and/or right as needed) × 2 — Use OEM specification
• Cylinder head bolts (complete set - NEW REQUIRED) × 1 — Use OEM specification
• Valve cover gasket × 2 — Use OEM specification
• Turbocharger gaskets × 2 — Use OEM specification
• Exhaust manifold gaskets × 2 — Use OEM specification
• Timing chain tensioner gaskets × 2 — Use OEM specification
• Water pump gasket × 1 — Use OEM specification
• Thermostat housing gasket × 1 — Use OEM specification
• Coolant crossover pipe O-rings × 1 — Use OEM specification
• Spark plugs (all 6) × 6 — Motorcraft SP-520 or equivalent

Fluids

• Motorcraft Orange Coolant — 13 qt
• Motorcraft 5W-20 Synthetic Blend — 6 qt

Preparation

1. Disconnect negative battery cable and wait 10 minutes for airbag system to depower
2. Drain engine coolant completely from radiator petcock and engine block drain plugs
3. Drain engine oil and remove oil filter
4. Remove engine cover and air intake system including both air filter housings
5. Relieve fuel system pressure by removing fuel pump fuse and cranking engine until it stalls
6. Remove radiator upper and lower hoses, heater hoses, and coolant reservoir
7. Tag and photograph all vacuum lines, electrical connectors, and fuel lines for reinstallation reference
8. Support engine from above using support bar across fender rails or attach hoist to engine lift eyes

Procedure

1. 1

   Remove right-side turbocharger assembly
   Disconnect turbocharger oil feed line at engine block and oil return line at turbo. Remove heat shields. Disconnect exhaust downpipe from turbocharger outlet using penetrating oil on studs. Remove turbo-to-exhaust manifold mounting nuts and carefully extract turbocharger assembly. Inspect wastegate actuator and verify no shaft play in turbo bearing.
2. 2

   Remove exhaust manifold and accessories
   Remove exhaust manifold heat shields and all mounting fasteners. Extract exhaust manifold carefully to avoid warping. Remove ignition coils and spark plugs from cylinder head. Disconnect camshaft position sensor and variable cam timing (VCT) solenoid electrical connectors. Remove valve cover by loosening bolts in reverse of tightening sequence (outside-in pattern).
   Torque spec

   Sensor Bolts12 Nm (9 lb-ft)

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

   Remove front engine accessories and timing cover
   Remove serpentine belt and tensioner. Remove crankshaft pulley using harmonic balancer puller (do not hammer). Remove power steering pump and set aside without disconnecting hoses. Remove engine oil dipstick tube. Remove all timing cover bolts and carefully pry cover away from engine block. Remove crankshaft front seal if damaged.
   Torque spec

   Mounting Bolts31 Nm (23 lb-ft)
4. 4

   Set engine to TDM and lock timing components
   Rotate crankshaft clockwise using socket on crankshaft bolt until cylinder #1 is at Top Dead Center on compression stroke. Verify timing marks on camshaft sprockets align with marks on cylinder head. Install camshaft alignment tools (Ford 303-1248 or equivalent) into slots on camshaft rear faces. DO NOT rotate engine once tools are installed.
   ⚠Improper timing alignment will result in bent valves when engine is cranked. Triple-check alignment before proceeding.
5. 5

   Remove timing chains and components
   Remove timing chain tensioners by compressing tensioner arm and sliding locking pin into hole to hold tension off. Remove tensioner mounting bolts. Remove timing chain guides. Mark timing chain direction of rotation with paint marker. Remove camshaft sprocket bolts while holding camshafts with alignment tool. Remove timing chains from camshaft and crankshaft sprockets. Verify crankshaft position has not moved.
   Torque spec

   Mounting Bolts31 Nm (23 lb-ft)
6. 6

   Disconnect coolant and fuel system components
   Disconnect coolant crossover pipe from cylinder head using appropriate wrench to avoid rounding fittings. Remove thermostat housing if accessing front of head. Disconnect fuel rail from injectors by releasing spring clips. Remove fuel rail mounting bolts and extract fuel rail with injectors attached. Cap all fuel openings immediately to prevent contamination.
   Torque spec

   Mounting Bolts31 Nm (23 lb-ft)
7. 7

   Remove cylinder head bolts in proper sequence
   Loosen cylinder head bolts in reverse of tightening sequence (consult service manual diagram - typically start from outside and work inward in spiral pattern). Loosen each bolt 1/4 turn at a time in sequence to prevent warping. Once all bolts are loose, remove completely. Inspect bolts for necking or damage. Discard all bolts - they MUST NOT be reused.
   ⚠Never loosen head bolts out of sequence or all at once. This can warp the aluminum cylinder head beyond repair.
8. 8

   Remove cylinder head from engine block
   Carefully lift cylinder head straight up off engine block. Head may be stuck to block by gasket - use plastic pry bars in designated lift points only, never between sealing surfaces. Do not tilt head excessively during removal as camshafts and valves can fall out. Place cylinder head on clean padded surface with combustion chambers facing up. Remove and inspect head gasket, noting any failure points.
   ⚠Cylinder head weighs approximately 50 lbs. Use proper lifting technique or get assistance to prevent injury or dropping head.
9. 9

   Clean and inspect mating surfaces
   Use plastic gasket scraper to remove all gasket material from engine block deck surface and cylinder head mating surface. Do NOT use metal scrapers on aluminum surfaces. Clean surfaces with brake cleaner and lint-free cloths. Inspect block deck for warping using precision straight edge and feeler gauge - maximum warpage is 0.003 inch. Check head surface flatness same way. Inspect cylinder bores for scoring or damage. Verify all coolant and oil passages are clear.
   ℹ️If cylinder head warpage exceeds 0.003 inch, head must be professionally resurfaced. Maximum material removal is 0.010 inch total over head life.
10. 10

    Install new head gasket and position cylinder head
    Install new head gasket onto engine block with orientation marks UP and FRONT visible. Gasket has locating dowels - verify it seats properly. Apply light coat of clean engine oil to new cylinder head bolt threads and underside of bolt heads. Carefully lower cylinder head onto block, aligning with dowel pins. Ensure head seats fully on gasket with no gaps.
    ⚠Head gasket has specific orientation and cannot be reversed. Verify TOP and FRONT markings are correctly positioned before installing head.
11. 11

    Install and torque cylinder head bolts in sequence
    Install all new cylinder head bolts finger-tight. Following proper tightening sequence from service manual (typically center-out spiral pattern), torque all bolts to 30 ft-lb (40 Nm) using torque wrench. Then rotate each bolt an additional 90 degrees using angle gauge in same sequence. Finally, rotate each bolt another 90 degrees (total 180 degrees beyond initial torque) in same sequence. Mark bolts with paint to track rotation.
    ⚠Head bolt torque sequence and angle-torque procedure is CRITICAL. Verify your specific year uses 30 ft-lb + 90° + 90° specification. Some years use different initial torque.
    Torque spec

    Cylinder Head Bolts40 Nm (30 lb-ft) + 180°
12. 12

    Reinstall timing chains with proper alignment
    Verify crankshaft and camshafts have not moved from TDC position. Install timing chains onto crankshaft sprocket first, then route around camshaft sprockets ensuring colored links align with sprocket timing marks. Install camshaft sprocket bolts and torque to specification while holding camshafts with alignment tool. Install timing chain guides and tensioners. Remove tensioner locking pins to apply tension. Remove camshaft alignment tools and rotate engine 2 complete revolutions by hand to verify timing marks realign.
    ⚠️Rotate engine by hand ONLY. Do not use starter. If resistance is felt, STOP immediately - timing may be incorrect causing valve-to-piston interference.
    Torque spec

    Mounting Bolts31 Nm (23 lb-ft)
13. 13

    Install timing cover and front accessories
    Install new timing cover gasket and front crankshaft seal. Apply small bead of RTV silicone to timing cover corners where gasket meets. Install timing cover and torque bolts to specification in cross-pattern. Install crankshaft pulley and torque to specification. Reinstall power steering pump, serpentine belt tensioner, and drive belt. Install oil dipstick tube with new O-ring.
    Torque spec

    Cover Bolts19 Nm (14 lb-ft)

    Mounting Bolts31 Nm (23 lb-ft)
14. 14

    Reinstall cylinder head components
    Install new valve cover gasket in cover groove. Apply small dabs of RTV at camshaft cap corners. Install valve cover and torque bolts in sequence (center-out) to specification. Install fuel rail with new O-rings on injectors and torque mounting bolts. Reconnect fuel lines. Install coolant crossover pipe with new O-rings. Install thermostat housing with new gasket if removed. Install spark plugs and torque to specification. Install ignition coils.
    Torque spec

    Cover Bolts19 Nm (14 lb-ft)

    Gasket Bolts23 Nm (17 lb-ft)

    Mounting Bolts31 Nm (23 lb-ft)
15. 15

    Install exhaust manifold and turbocharger
    Install exhaust manifold with new gaskets and torque bolts in sequence per service manual. Install manifold heat shields. Install turbocharger to exhaust manifold with new gaskets and torque nuts to specification. Connect turbo oil feed line with new crush washers and torque to spec. Connect oil return line with new gasket. Install turbo heat shields. Connect exhaust downpipe to turbocharger outlet with new gasket.
    Torque spec

    Gasket Bolts23 Nm (17 lb-ft)

    Mounting Bolts31 Nm (23 lb-ft)

Reassembly

1. Reinstall all vacuum lines, electrical connectors, and sensors according to photos and tags from disassembly
2. Install new engine oil filter and fill engine with 6 quarts Motorcraft 5W-20 synthetic blend oil
3. Fill cooling system with 13 quarts Motorcraft Orange coolant mixture (50/50 with distilled water)
4. Reinstall air intake system including both air filter housings and engine cover
5. Reconnect negative battery cable
6. Bleed cooling system by running engine with heater on full hot until thermostat opens and upper radiator hose becomes hot

Verification

• Start engine and verify oil pressure comes up within 5 seconds - if not, shut down immediately
• Listen for abnormal engine noises, ticking, or knocking that could indicate timing issues or loose components
• Check for coolant, oil, and fuel leaks around all connections while engine warms up
• Verify no exhaust leaks at turbocharger or manifold connections - look for black soot marks
• Allow engine to reach full operating temperature and verify cooling fans cycle properly
• Check for stored diagnostic trouble codes using scan tool - address any timing or sensor codes immediately
• Perform test drive monitoring engine temperature, boost pressure, and overall performance
• Recheck cylinder head bolt torque after engine has cooled completely (some manufacturers specify retorque, verify in service manual)
• Monitor coolant and oil levels over next few days, topping off as needed during break-in period

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