This procedure covers removal and 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
• Cylinder head bolt set (both banks) × 1 — Use OEM - bolts are torque-to-yield and must be replaced
• Valve cover gasket - left × 1 — Use OEM specification
• Valve cover gasket - right × 1 — Use OEM specification
• Exhaust manifold gasket set (both banks) × 1 — Use OEM specification
• Intake manifold gasket set × 1 — Use OEM specification
• Timing cover gasket × 1 — Use OEM specification
• Camshaft cap bolt set × 1 — Use OEM - verify if reusable per service manual
• Coolant (Motorcraft Orange) × 1 — VC-3DIL-B or equivalent
• Engine oil 0W-20 full synthetic × 1 — Motorcraft specification
• RTV silicone gasket maker (Ford-approved) × 1 — TA-357 or equivalent
• Engine degreaser/cleaner × 1 — Use OEM specification

Fluids

• Motorcraft Orange Coolant — 13 qt
• Motorcraft 0W-20 Full Synthetic Engine Oil — 6 qt

Preparation

1. Ensure engine is completely cold before starting work
2. Disconnect negative battery cable and wait 10 minutes for airbag system to discharge
3. Remove engine cover and air intake system including air filter housing
4. Relieve fuel system pressure by removing fuel pump fuse and cranking engine until it stalls
5. Drain engine coolant completely into appropriate container by opening radiator petcock and lower radiator hose
6. Drain engine oil and remove oil filter
7. Support engine from above using engine support fixture or hoist with load leveler
8. Raise and secure vehicle on jack stands if additional access is needed
9. Remove front wheels if removing exhaust manifolds from underneath
10. Label and photograph all electrical connectors, vacuum lines, and hose routing before disconnection

Procedure

1. 1

   Remove upper engine components and accessories
   Disconnect throttle body electrical connector and remove throttle body. Remove charge air cooler outlet pipe. Disconnect all fuel lines using proper disconnect tools (fuel will be under residual pressure). Remove ignition coils from all cylinders and spark plugs. Disconnect all engine harness connectors that will interfere with cylinder head removal including injector connectors, cam position sensors, variable valve timing solenoids, and knock sensors. Remove accessory drive belt and tensioner.
   ⚠Use proper fuel line disconnect tools to avoid damaging quick-connect fittings
2. 2

   Remove valve covers
   Disconnect PCV hoses and breather tubes from both valve covers. Remove valve cover bolts in reverse of tightening sequence (outside to inside pattern). Carefully lift valve covers off - they may be sealed with RTV. If stuck, gently tap with rubber mallet. Do not pry between cover and head as this can damage sealing surfaces. Remove and discard valve cover gaskets.
   Torque spec

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

   Remove intake manifold assembly
   Disconnect brake booster vacuum line and all vacuum connections to intake manifold. Remove intake manifold bolts in reverse order of installation sequence (start from center and work outward). Lift intake manifold assembly off engine. Inspect manifold mounting surface for damage. Remove and discard intake manifold gaskets. Cover intake ports with clean shop towels to prevent debris entry.
   ℹ️Keep all intake manifold bolts organized - some may be different lengths
   Torque spec

   Intake Manifold Bolts28 Nm (21 lb-ft)
4. 4

   Remove exhaust manifolds and turbochargers
   Disconnect exhaust downpipes from turbocharger outlets. Remove heat shields from both exhaust manifolds. Disconnect turbocharger oil feed lines and coolant lines (residual oil and coolant will drain). Disconnect oxygen sensor connectors. Remove turbochargers if necessary for access (may be able to leave attached depending on approach). Remove exhaust manifold nuts starting from center and working outward. Remove exhaust manifolds and discard gaskets.
   ⚠Exhaust studs are prone to breaking on aluminum heads. Apply penetrating oil 24 hours before removal if possible
   Torque spec

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

   Remove timing chain cover and set timing position
   Remove crankshaft pulley using harmonic balancer puller (do not use jaw-type puller on pulley face). Remove water pump if it interferes with timing cover removal. Remove all timing cover bolts and carefully separate cover from engine block - it is sealed with RTV. Rotate crankshaft to TDC position for cylinder #1 (both intake and exhaust cam lobes on cylinder #1 should point outward away from each other). Verify timing marks align. Install Ford camshaft alignment tool set (303-1248) to lock camshafts in position.
   ⚠️Once timing chains are loosened, DO NOT rotate crankshaft or camshafts independently - piston-to-valve contact will occur causing severe damage
   Torque spec

   Cover Bolts19 Nm (14 lb-ft)
6. 6

   Remove timing chains and camshaft components
   Mark timing chain position on camshaft and crankshaft sprockets for reference. Release timing chain tensioners using appropriate locking tools and remove tensioners. Remove timing chain guides. Slide timing chains off camshaft and crankshaft sprockets. Leave camshaft alignment tools installed. Remove camshaft position sensors. Remove Variable Valve Timing (VVT) solenoids. Loosen camshaft cap bolts evenly in reverse of tightening sequence (outside to inside, 1/4 turn at a time to prevent warping). Remove camshaft caps keeping them in order. Carefully lift camshafts out of cylinder heads and place on clean surface.
   ⚠Camshaft caps must be reinstalled in exact same position and orientation. Mark them clearly during removal
   Torque spec

   Camshaft Cap Bolts19 Nm (14 lb-ft)

   Mounting Bolts54 Nm (40 lb-ft)
7. 7

   Remove cylinder head bolts and cylinder heads
   Loosen cylinder head bolts in reverse of tightening sequence (start from outside and work toward center in specified pattern per Ford service manual). Loosen bolts 1/4 turn at a time in multiple passes to prevent head warping. Once all bolts are loose, remove them completely and discard - these are torque-to-yield bolts and must not be reused. Check that all electrical connectors, coolant passages, and mounting points are disconnected. Use plastic pry points (not between sealing surfaces) to break head gasket seal if needed. Carefully lift cylinder head straight up off engine block. Remove and discard head gaskets. Repeat for second cylinder head.
   ⚠️Never reuse torque-to-yield cylinder head bolts. Using old bolts will result in gasket failure and potential catastrophic engine damage
   Torque spec

   Cylinder Head Bolts40 Nm (30 lb-ft) + 180°
8. 8

   Inspect and clean all mating surfaces
   Thoroughly clean all gasket surfaces on cylinder heads and engine block using appropriate gasket scrapers. Use plastic scrapers on aluminum surfaces to prevent gouging. Remove all old gasket material, RTV, and carbon deposits. Clean surfaces with brake cleaner or degreaser and wipe with lint-free cloths. Inspect cylinder head deck surfaces with precision straight edge and feeler gauge - maximum allowable warpage is 0.003 inches. Check block deck surface similarly. Inspect for cracks in combustion chambers, between valve seats, and in coolant passages. If warpage exceeds specification or cracks are found, cylinder heads must be machined or replaced. Clean all bolt holes in block with thread chaser and compressed air to remove coolant and debris.
   ℹ️Any warpage beyond 0.003 inches requires cylinder head resurfacing. Maximum material removal varies by year - consult service manual
   Torque spec

   Gasket Surface Bolts23 Nm (17 lb-ft)
9. 9

   Install new head gaskets and position cylinder heads
   Verify block deck surface is completely clean and dry. Install new cylinder head gaskets on engine block - ensure gaskets are oriented correctly (UP marks facing up, alignment dowels properly engaged). Do not use any sealant on head gaskets unless specifically required by manufacturer. Verify head gasket coolant and oil passage holes align perfectly with block passages. Carefully lower cylinder head onto block, aligning with dowel pins. Ensure head seats fully on gasket without shifting gasket position. Repeat for second cylinder head.
10. 10

    Install and torque new cylinder head bolts
    Install new cylinder head bolts (never reuse old bolts) and hand tighten in the proper sequence pattern starting from center and working outward. Using calibrated torque wrench, torque all bolts to Step 1: 40 Nm (30 lb-ft) following proper sequence. Using torque angle gauge or electronic torque wrench with angle measurement, perform Step 2: rotate all bolts an additional 90 degrees in sequence. Perform Step 3: rotate all bolts another 90 degrees in sequence (total 180 degrees beyond initial torque). Verify with your specific year service manual as some applications use different torque sequence (22 lb-ft, then 33 lb-ft, then 180 degrees total). Mark completed bolts to avoid missing any during angle tightening.
    ⚠Torque sequence and values are critical. Follow exact pattern from Ford service manual for your specific model year
    Torque spec

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

    Install camshafts and timing components
    Lubricate camshaft journals and lobes with clean engine oil. Install camshafts into cylinder heads in correct positions (intake and exhaust marked). Ensure camshaft timing alignment tool can be installed to verify position. Install camshaft caps in exact original positions with arrows or marks pointing toward front of engine. Install camshaft cap bolts and tighten in proper sequence (center caps first, then outer caps) to specified torque. Install VVT solenoids and camshaft position sensors. Install timing chains onto crankshaft and camshaft sprockets, aligning all timing marks precisely per service manual. Install timing chain guides and tensioners. Remove camshaft alignment tools and verify engine rotates smoothly through two complete revolutions, re-checking timing mark alignment.
    ⚠️Verify timing marks align exactly before proceeding. Incorrect timing will cause immediate engine damage on startup
    Torque spec

    Camshaft Cap Bolts19 Nm (14 lb-ft)

    Mounting Bolts54 Nm (40 lb-ft)
12. 12

    Install timing cover and front accessories
    Clean timing cover and block mating surfaces thoroughly. Apply thin bead of Ford-approved RTV silicone (TA-357) to timing cover per service manual diagram (typically small beads at block-to-head corners). Install new timing cover gasket if equipped, or follow RTV-only procedure per manual. Install timing cover and bolts, tightening in star pattern to specification. Install water pump with new gasket if removed. Install crankshaft pulley, torquing to specification (note this is typically a multi-step torque). Install accessory drive belt tensioner and belt.
    ℹ️RTV must cure before adding coolant. Check specific product cure time, typically 30-60 minutes
    Torque spec

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

    Install exhaust and intake manifolds
    Install new exhaust manifold gaskets on cylinder heads. Position exhaust manifolds and install new nuts finger tight. Torque exhaust manifold nuts in proper sequence (center out) to specification. Install turbochargers if removed, with new gaskets. Reconnect turbo oil feed and coolant lines with new crush washers. Install heat shields. Position new intake manifold gaskets on cylinder heads. Install intake manifold and start all bolts. Torque intake manifold bolts in proper sequence (center out) to specification. Reconnect all vacuum lines, brake booster line, and PCV system.
    Torque spec

    Exhaust Manifold Nuts39 Nm (29 lb-ft)

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

    Install valve covers and upper components
    Install new valve cover gaskets (ensure properly seated in cover grooves). Apply small dab of RTV at front corners where head meets timing cover if specified by service manual. Position valve covers on cylinder heads. Install valve cover bolts and torque in proper sequence (typically outside to inside) to specification. Reconnect PCV hoses and breather tubes. Install spark plugs torquing to specification. Install ignition coils. Reconnect all engine harness connectors including injectors, cam sensors, VVT solenoids, knock sensors, and all other previously disconnected sensors. Install throttle body with new gasket. Install charge air cooler piping. Reconnect fuel lines ensuring positive click engagement. Install air intake system and engine cover.
    Torque spec

    Cover Bolts19 Nm (14 lb-ft)
15. 15

    Refill fluids and perform initial startup
    Install new oil filter and refill engine with 6 quarts of Motorcraft 0W-20 full synthetic oil. Close coolant drain and refill cooling system with 13 quarts Motorcraft Orange coolant, bleeding air from system per service manual procedure (typically requires running engine with heat on, burping at specific points). Reconnect negative battery cable. Before starting engine, turn ignition to ON position (not start) and cycle 3-4 times to build fuel pressure and check for fuel leaks. Verify no tools or parts remain in engine bay. Start engine and immediately verify oil pressure on gauge. Listen for unusual noises. Allow engine to idle and warm up to operating temperature while monitoring for leaks at head gaskets, valve covers, intake manifold, exhaust manifolds, and all coolant connections. Check coolant level and top off as needed after air purges from system.
    ⚠If any unusual noises occur on startup (knocking, rattling), shut down immediately and verify timing chain installation and timing marks

Reassembly

1. Torque all fasteners to exact specifications in proper sequence - head bolts, camshaft caps, intake and exhaust manifolds are sequence-critical
2. Use only new torque-to-yield cylinder head bolts - never reuse old bolts
3. Verify timing alignment multiple times before final cover installation
4. Allow RTV sealant to cure per manufacturer specifications before filling with coolant
5. Double-check all electrical connectors are fully seated and locked

Verification

• Start engine and verify immediate oil pressure indication on gauge within 3-5 seconds
• Verify no coolant, oil, or fuel leaks at all gasket surfaces and connections
• Listen for smooth engine operation with no unusual knocking, ticking, or rattling noises
• Allow engine to reach full operating temperature and verify cooling fans cycle properly
• Check for any exhaust leaks at manifold gaskets under load
• Verify no check engine lights or diagnostic trouble codes are present
• Road test vehicle under moderate load and verify normal power delivery and no misfires
• Re-check coolant level after first heat cycle - top off as needed
• After 50-100 miles, re-check all accessible fasteners and fluid levels
• Monitor for any oil consumption or coolant loss over first 500 miles indicating potential gasket issues

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