Complete replacement of both cylinder head gaskets on the 3.5L EcoBoost V6 engine, including removal of intake and exhaust manifolds, timing components, and cylinder heads.

Warnings

Tools required

Parts

• Cylinder head gasket (left) × 1 — Use OEM Ford specification
• Cylinder head gasket (right) × 1 — Use OEM Ford specification
• Valve cover gasket (left) × 1 — Use OEM Ford specification
• Valve cover gasket (right) × 1 — Use OEM Ford specification
• Intake manifold gaskets × 1 — Use OEM Ford specification
• Exhaust manifold gaskets (left) × 1 — Use OEM Ford specification
• Exhaust manifold gaskets (right) × 1 — Use OEM Ford specification
• Timing cover gasket × 1 — Use OEM Ford specification
• Turbocharger-to-exhaust manifold gaskets × 2 — Use OEM Ford specification
• Cylinder head bolts (complete set) × 1 — Use OEM Ford torque-to-yield bolts - DO NOT REUSE
• Coolant temperature sensor O-ring × 2 — Use OEM specification
• Spark plugs × 6 — Motorcraft SP-515 or equivalent
• Oil filter × 1 — Motorcraft FL-910-S or equivalent
• Miscellaneous vacuum hoses and clips (as needed) × 1 — Inspect and replace damaged hoses

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 discharge
2. Drain engine coolant completely from radiator and engine block drain plugs
3. Drain engine oil and remove oil filter
4. Remove engine cover and air intake system including air filter box and intake tubes
5. Relieve fuel system pressure by removing fuel pump fuse and running engine until it stalls
6. Remove front wheels and raise vehicle on jack stands for access to lower components
7. Support engine using engine support bar across fender aprons or engine hoist from above
8. Label and photograph all electrical connectors, vacuum hoses, and fuel lines before disconnecting
9. Create organized storage system for bolts with labels indicating location and sequence

Procedure

1. 1

   Remove turbochargers and exhaust components
   Disconnect exhaust Y-pipe from both turbocharger outlets. Remove heat shields from both turbochargers. Disconnect oil supply and return lines from both turbochargers (note orientation). Disconnect wastegate actuator vacuum lines. Remove turbocharger mounting bolts and carefully remove both turbochargers from exhaust manifolds. Cap all openings to prevent debris entry.
2. 2

   Remove intake manifold assembly
   Disconnect throttle body electrical connector and all intake manifold vacuum lines. Remove PCV hoses and brake booster vacuum line. Disconnect fuel rail and set aside (do not separate injectors unless necessary). Remove intake manifold bolts in reverse of tightening sequence (outside to inside pattern). Carefully lift intake manifold assembly away from engine.
   Torque spec

   Intake Manifold Bolts28 Nm (21 lb-ft)
3. 3

   Remove valve covers and ignition components
   Disconnect ignition coil connectors from all six cylinders. Remove ignition coils and set aside. Remove valve cover bolts in reverse spiral pattern from outside to inside. Carefully pry valve covers loose using plastic pry tool at designated pry points. Remove valve covers and gaskets. Remove spark plugs from all cylinders and inspect condition.
   Torque spec

   Valve Cover Bolts16 Nm (12 lb-ft)
4. 4

   Remove exhaust manifolds
   Working on both sides of engine, remove exhaust manifold heat shields. Disconnect oxygen sensor connectors and carefully remove sensors from manifolds. Remove exhaust manifold nuts in reverse sequence (inside to outside). Remove left and right exhaust manifolds and set aside. Inspect manifolds for cracks or warping.
   ⚠Exhaust manifold studs are prone to breakage on high-mileage engines. Have stud removal tools available if studs break.
   Torque spec

   Exhaust Manifold Nuts39 Nm (29 lb-ft)
5. 5

   Remove timing drive components access
   Remove accessory drive belt and tensioner. Remove power steering pump and set aside without disconnecting lines. Remove crankshaft pulley using harmonic balancer puller (do not use impact tools). Remove front timing cover bolts and carefully remove timing cover with gasket. Verify timing marks on all components before proceeding.
   ⚠Mark exact position of timing chains, guides, and sprockets with paint pen before any removal. Take detailed photos from multiple angles.
6. 6

   Lock timing chains and remove camshaft components
   Rotate crankshaft to TDC position cylinder #1 (verify all timing marks align per service manual). Install camshaft holding tools on both banks to lock camshafts in position. Install timing chain tensioner locking pins on both primary and secondary tensioners. Remove timing chain tensioners. Mark chain-to-sprocket position. Remove camshaft sprocket bolts and carefully slide sprockets off camshafts while supporting timing chains.
   ⚠️Camshafts and crankshaft MUST remain locked in position throughout this procedure. Movement will cause valve-to-piston contact and severe engine damage.
7. 7

   Remove camshafts
   Working on one cylinder bank at a time, loosen camshaft cap bolts in reverse of tightening sequence (inside to outside, multiple passes). Remove camshaft caps and keep in order with cylinder bank identification. Carefully lift intake and exhaust camshafts from each cylinder head. Place camshafts on clean surface and label left/right bank and intake/exhaust position. Inspect camshaft journals and lobes for scoring or wear.
   Torque spec

   Camshaft Cap Bolts19 Nm (14 lb-ft)
8. 8

   Remove cylinder heads
   Disconnect all remaining coolant hoses from cylinder heads. Disconnect remaining electrical connectors including coolant temperature sensors. Loosen cylinder head bolts in reverse of tightening sequence (outside to inside spiral pattern) in multiple passes. Remove all cylinder head bolts and discard (torque-to-yield bolts cannot be reused). Carefully lift cylinder heads straight up off engine block using lifting eyes or pry points. Do not pry between head and block surfaces.
   ⚠Cylinder heads are heavy (approximately 50-60 lbs each). Use proper lifting technique or assistance to prevent injury or dropping heads.
   Torque spec

   Cylinder Head Bolts40 Nm (30 lb-ft) + 180°
9. 9

   Inspect and clean mating surfaces
   Remove all old gasket material from cylinder head and engine block surfaces using plastic gasket scraper. Clean surfaces thoroughly with brake cleaner. Inspect cylinder head surfaces for flatness using precision straight edge and feeler gauge at multiple points. Maximum allowable warpage is 0.003 inch. If warpage exceeds specification, heads must be machined. Inspect block surface for damage or debris. Clean cylinder bores carefully and ensure no debris falls into crankcase.
   ⚠Do not use metal scrapers or abrasive pads on aluminum surfaces. This will cause surface damage and gasket sealing issues.
10. 10

    Install new cylinder head gaskets and heads
    Verify engine block and cylinder head surfaces are completely clean and dry. Install new cylinder head gaskets on engine block with orientation marks (TOP, FRONT) in correct position. Do not use any sealant on head gaskets. Carefully lower cylinder heads onto block, aligning dowel pins. Install NEW cylinder head bolts hand-tight in spiral pattern from inside to outside. Torque cylinder head bolts in three steps following sequence: Step 1 - torque all bolts to 30 lb-ft in sequence, Step 2 - rotate all bolts additional 90 degrees in sequence, Step 3 - rotate all bolts final 90 degrees in sequence.
    ⚠Head bolt torque sequence is critical. Follow exact pattern from service manual starting at center and working outward in spiral.
    Torque spec

    Cylinder Head Bolts40 Nm (30 lb-ft) + 180°
11. 11

    Reinstall camshafts and timing components
    Lubricate camshaft journals and lobes with engine assembly lube. Install camshafts into correct cylinder heads in correct orientation (verify timing marks). Install camshaft caps in correct positions and orientation (caps are numbered and marked for position). Torque camshaft cap bolts to 14 lb-ft in sequence from inside to outside in multiple passes. Verify camshafts rotate freely. Reinstall camshaft sprockets with timing chains in marked positions. Install timing chain tensioners with locking pins still installed. Remove camshaft holding tools and verify all timing marks align correctly.
    ⚠Verify timing chain alignment marks match original photos before removing locking pins from tensioners.
    Torque spec

    Camshaft Cap Bolts19 Nm (14 lb-ft)
12. 12

    Install exhaust manifolds
    Install new exhaust manifold gaskets on cylinder heads. Position left and right exhaust manifolds and install mounting nuts hand-tight. Torque exhaust manifold nuts to 29 lb-ft in sequence from inside to outside. Install oxygen sensors with anti-seize on threads. Reconnect oxygen sensor electrical connectors. Install exhaust manifold heat shields.
    Torque spec

    Exhaust Manifold Nuts39 Nm (29 lb-ft)
13. 13

    Install valve covers and intake manifold
    Install new valve cover gaskets in valve covers (ensure gasket is fully seated in cover groove). Apply small amount of silicone sealant at front corners where timing cover meets cylinder head. Install valve covers and torque bolts to 12 lb-ft in spiral pattern from inside to outside. Install new intake manifold gaskets. Position intake manifold and install bolts hand-tight. Torque intake manifold bolts to 21 lb-ft in sequence from inside to outside. Reconnect all vacuum lines, PCV hoses, and electrical connectors to intake manifold.
    Torque spec

    Valve Cover Bolts16 Nm (12 lb-ft)

    Intake Manifold Bolts28 Nm (21 lb-ft)
14. 14

    Reinstall turbochargers and complete assembly
    Install new turbocharger-to-exhaust manifold gaskets. Position both turbochargers and install mounting hardware. Reconnect turbocharger oil supply and return lines with new crush washers. Reconnect wastegate actuator vacuum lines. Install turbocharger heat shields. Reinstall front timing cover with new gasket. Install crankshaft pulley and torque to specification. Reinstall power steering pump and accessory drive belt. Install new spark plugs with anti-seize on threads. Install ignition coils and reconnect electrical connectors.
15. 15

    Final assembly and fluid refill
    Reconnect all remaining electrical connectors, fuel lines, and coolant hoses. Reinstall air intake system and engine cover. Lower vehicle and remove support equipment. Install new oil filter and refill engine with 6 quarts of Motorcraft 5W-20 oil. Refill cooling system with 13 quarts of Motorcraft Orange Coolant and bleed air from system per service manual procedure. Reconnect battery negative cable.

Reassembly

1. Always use new torque-to-yield cylinder head bolts - never reuse old bolts
2. Follow exact torque sequences for all critical fasteners, especially cylinder heads and camshaft caps
3. Verify all timing marks align correctly before finalizing timing chain installation
4. Double-check all electrical connectors, vacuum lines, and fuel connections are secure
5. Ensure cooling system is completely bled of air to prevent overheating

Verification

• Perform crankshaft rotation test by hand through two complete revolutions to verify no binding or interference
• Check for fuel leaks by cycling ignition to prime fuel system before starting engine
• Start engine and verify oil pressure builds immediately (within 2-3 seconds)
• Check for coolant, oil, or exhaust leaks while engine warms to operating temperature
• Verify no unusual engine noises, smooth idle, and proper operation of both turbochargers
• Monitor coolant level and temperature during initial test drive, checking for overheating
• Perform boost pressure test to verify turbochargers operate correctly under load
• Re-check all fluid levels after test drive and inspect for any leaks

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