Complete replacement of timing chains, guides, tensioners, and cam phasers on the 3.5L EcoBoost V6 engine. This is a complex internal engine job requiring precise timing alignment and extensive disassembly.

Warnings

Tools required

Parts

• Timing chain kit (primary and secondary chains) × 1 — Use OEM Ford kit recommended
• Timing chain tensioners (left and right) × 2 — Included in timing kit or separate
• Timing chain guides × 4 — Included in timing kit
• Cam phaser bolts with diamond friction washers × 4 — Must be new, washers non-reusable
• Crankshaft pulley bolt with friction washer × 1 — Use OEM specification
• Valve cover gaskets (left and right) × 2 — Use OEM specification
• Timing cover gasket × 1 — Use OEM specification
• Crankshaft front seal × 1 — Use OEM specification
• Oil drain plug crush washer × 1 — Use OEM specification
• Engine oil filter × 1 — Motorcraft FL-910-S or equivalent
• RTV silicone sealant × 1 — Motorcraft TA-31
• VVT solenoid O-rings × 4 — Use OEM specification

Fluids

• Motorcraft 0W-20 Full Synthetic — 6 qt
• Motorcraft Orange Coolant — 2 qt

Preparation

1. Verify you have complete Ford service manual with timing mark diagrams and camshaft bolt torque sequences
2. Ensure engine is completely cold and vehicle is on level ground
3. Disconnect negative battery cable and wait 10 minutes for airbag system to discharge
4. Remove engine cover (plastic cover over engine)
5. Drain engine oil completely and replace drain plug with new crush washer
6. Drain coolant from radiator and engine block drain plugs
7. Remove air intake system, mass airflow sensor, and intake tubes
8. Support engine from above using support bar or engine hoist with load leveler
9. Remove accessory drive belt and tensioner
10. Label and disconnect all electrical connectors from valve covers, cam sensors, and VVT solenoids
11. Remove both ignition coils and spark plugs for easier rotation
12. Take multiple photos of routing for hoses, wiring, and bracket positions

Procedure

1. 1

   Remove crankshaft pulley and front accessories
   Use breaker bar with 21mm socket to remove crankshaft pulley bolt (turn counterclockwise). You may need to lock the crankshaft using a strap wrench on the pulley or have an assistant hold the vehicle in gear with brakes applied. Remove pulley using puller if necessary. Remove power steering pump (if equipped) and AC compressor, supporting them aside without disconnecting lines. Remove water pump pulley.
2. 2

   Remove valve covers
   Remove bolts securing both valve covers in reverse of tightening sequence (consult service manual). Carefully lift valve covers off, breaking gasket seal with gentle prying if needed. Inspect rocker arms and valve train for wear. Clean all gasket material from valve cover mating surfaces on cylinder heads using plastic scraper.
3. 3

   Remove timing cover
   Remove all timing cover bolts noting their different lengths and locations. There are three different bolt sizes (6mm, 8mm, and 10mm). Mark or photograph bolt locations for reassembly. Carefully pry timing cover off using plastic pry tools at designated pry points only. Do not damage sealing surfaces. Remove and discard old timing cover gasket and front crankshaft seal.
4. 4

   Rotate engine to TDC and verify timing marks
   Rotate crankshaft clockwise using socket on crankshaft snout until cylinder #1 is at TDC compression stroke. Verify all timing marks align: crankshaft keyway at 12 o'clock, both cam sprockets with timing marks aligned to cylinder head surfaces, cam phaser marks aligned. Install timing pins per service manual if available. Take clear photos of all timing mark positions before proceeding.
   ⚠️All timing marks MUST be exactly aligned before removing chains. Any deviation will cause incorrect reassembly and engine damage.
5. 5

   Remove cam phasers and camshaft sprockets
   Hold each camshaft stationary using wrench on the hex portion of the camshaft (between lobes). Remove cam phaser bolts from all four camshafts (two per cylinder bank). Remove cam phasers and camshaft sprockets. Keep left and right bank components separate and labeled. Inspect cam lobes and bearing surfaces for wear.
6. 6

   Remove timing chain tensioners and chains
   Remove timing chain tensioner bolts and extract tensioners from both banks. Note tensioner orientation. Remove secondary timing chains from both banks. Remove primary timing chain tensioner and primary chain from crankshaft sprocket. Remove timing chain guides and inspect for wear grooves. Replace any guides showing wear patterns deeper than 1mm.
7. 7

   Inspect and clean timing components
   Thoroughly inspect crankshaft sprocket and intermediate sprockets for wear or damage. Check camshaft sprocket mounting surfaces on camshafts for scoring. Clean all timing chain debris from oil passages and engine front. Verify oil pump pickup screen is clear. Check camshaft endplay and bearing clearances if excessive wear is suspected.
   ⚠Do NOT rotate crankshaft or camshafts independently with chains removed. This will cause piston-to-valve contact.
8. 8

   Install new timing chain guides
   Install all new timing chain guides in their correct positions per service manual diagrams. Tighten guide bolts to specification. Ensure guides are seated properly and move freely if they are spring-loaded. Verify no interference with sprocket rotation paths.
   Torque spec

   Timing Chain Guide Bolts12 Nm (9 lb-ft)
9. 9

   Prepare and install timing chain tensioners
   Using tensioner compression tool or bench vise, compress each new timing chain tensioner fully and install retaining pin or clip to hold in compressed position. Install tensioners in engine but DO NOT remove retaining pins yet. Tighten tensioner bolts to specification.
   Torque spec

   Timing Chain Tensioner25 Nm (18 lb-ft)
10. 10

    Install primary timing chain
    Verify crankshaft is still at TDC with keyway at 12 o'clock. Route new primary timing chain around crankshaft sprocket and intermediate sprockets, ensuring colored links (if equipped) align with timing marks on sprockets. Verify chain is properly seated in all sprockets before proceeding.
    ⚠️Primary chain alignment is critical. Misalignment will cause secondary chain misalignment and engine damage.
11. 11

    Install camshaft sprockets and secondary chains
    Install secondary timing chains on camshaft sprockets before installing sprockets on camshafts. Route chains around intermediate sprockets, aligning colored links with sprocket timing marks. Install camshaft sprockets on camshafts with timing marks aligned to cylinder head reference marks. Verify cam lobe positions match TDC positions per service manual.
12. 12

    Install cam phasers
    Apply medium-strength blue threadlocker to NEW cam phaser bolts (with new friction washers). Install cam phasers on all four camshafts, ensuring phasers are fully seated. Hold each camshaft stationary using wrench on hex. Tighten cam phaser bolts in two steps: first to 30 ft-lb, then rotate an additional 90 degrees using angle gauge.
    ⚠Old cam phaser bolts and washers MUST NOT be reused. Friction coating is one-time use only.
    Torque spec

    Camshaft Sprocket Bolts80 Nm (59 lb-ft)
13. 13

    Verify timing and release tensioners
    Triple-check all timing marks are correctly aligned: crankshaft keyway at 12 o'clock, cam phaser marks aligned per service manual, all colored chain links aligned with marks. Rotate crankshaft by hand two complete revolutions clockwise and verify all marks return to correct alignment. Only after verification, remove retaining pins from all timing chain tensioners allowing them to tension the chains. Rotate crankshaft two more revolutions and re-verify timing.
    ⚠️If timing marks do not return to exact alignment after rotation, STOP. Disassemble and identify error before proceeding.
14. 14

    Install new timing cover and crankshaft seal
    Install new crankshaft front seal into timing cover using seal driver. Apply thin bead of RTV silicone sealant to timing cover mating surface per service manual pattern. Install new timing cover gasket. Position timing cover on engine, ensuring proper alignment with dowel pins. Install timing cover bolts in correct locations (6mm, 8mm, and 10mm bolts). Tighten in sequence per service manual: 6mm bolts to 7 ft-lb, 8mm bolts to 18 ft-lb, 10mm bolts to 33 ft-lb. Allow RTV to cure per manufacturer instructions before adding oil.
    Torque spec

    Timing Cover Bolts12 Nm (9 lb-ft)
15. 15

    Install crankshaft pulley
    Clean crankshaft snout and pulley bore thoroughly. Install crankshaft pulley ensuring proper alignment with keyway. Install NEW crankshaft pulley bolt with new friction washer. Tighten in two steps: first to 37 ft-lb, then rotate an additional 90 degrees using angle gauge. Lock crankshaft during tightening using same method as removal.
    ⚠Crankshaft pulley bolt must be replaced with new bolt and washer. Old friction washer cannot be reused.
16. 16

    Reinstall valve covers
    Install new valve cover gaskets ensuring proper seating in gasket channels. Clean valve cover bolt holes in cylinder heads. Install valve covers and tighten bolts in sequence from center outward per service manual to 7 ft-lb in multiple passes. Reconnect all electrical connectors to cam sensors, VVT solenoids, and ignition coils.
17. 17

    Reinstall accessories and final assembly
    Reinstall water pump pulley, AC compressor, power steering pump (if equipped). Install accessory drive belt and tensioner. Reinstall air intake system and all ducting. Install new oil filter. Refill engine oil with 6 quarts of Motorcraft 0W-20 synthetic oil. Refill coolant system with Motorcraft Orange coolant. Reconnect negative battery cable.

Reassembly

1. Reverse preparation steps, ensuring all electrical connectors are properly seated and secured
2. Install all spark plugs and ignition coils with proper torque
3. Verify all tools and rags are removed from engine compartment
4. Double-check that all timing chain tensioner pins were removed before starting
5. Ensure all fluid levels are correct before starting engine

Verification

• Before starting engine, manually rotate crankshaft two complete revolutions by hand using socket on crankshaft pulley bolt. Verify smooth rotation with no binding or hard spots
• Start engine and immediately verify oil pressure indication on dash. If no pressure within 5 seconds, shut down immediately
• Listen for any abnormal chain noise, rattling, or timing-related sounds during initial startup
• Allow engine to idle and warm to operating temperature while monitoring for leaks at timing cover and valve covers
• Verify no check engine lights or fault codes related to cam/crank correlation
• Road test vehicle under light load and verify normal acceleration and power delivery
• Re-check oil and coolant levels after test drive, top off if necessary
• Inspect timing cover and valve cover areas for any signs of oil or coolant leakage after 50-100 miles of operation

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