This procedure replaces the timing chain guides on the 3.5L EcoBoost V6 engine, requiring removal of timing covers, chains, and setting timing alignment.

Warnings

Tools required

Parts

• Timing chain guide set (primary and secondary) × 1 — Use OEM specification
• Timing cover gasket × 1 — Use OEM specification
• Valve cover gaskets (both banks) × 2 — Use OEM specification
• Crankshaft front seal × 1 — Use OEM specification
• Timing chain tensioners × 2 — Use OEM specification
• Engine oil and filter × 1 — Motorcraft FL-500S
• Coolant × 1 — Motorcraft Orange
• RTV silicone sealant (Motorcraft TA-31) × 1 — TA-31
• Timing cover bolt set × 1 — Use OEM specification

Fluids

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

Preparation

1. Park vehicle on level surface and engage parking brake
2. Disconnect negative battery terminal and wait 10 minutes for airbag system to discharge
3. Remove engine cover and air intake assembly
4. Drain engine coolant into appropriate container
5. Drain engine oil and remove oil filter
6. Remove front wheels and raise vehicle on jack stands
7. Remove lower splash shields and undertray
8. Support engine from above using engine support bar or from below with jack and wood block under oil pan

Procedure

1. 1

   Remove accessory drive system
   Remove the serpentine belt by rotating the tensioner clockwise. Remove the belt tensioner assembly. Disconnect the power steering pump and set aside without disconnecting lines. Remove the A/C compressor mounting bolts and secure compressor aside without disconnecting refrigerant lines.
2. 2

   Remove crankshaft pulley
   Using the crankshaft pulley holder tool to prevent rotation, remove the crankshaft pulley bolt using a breaker bar. The bolt is very tight. Remove the crankshaft pulley from the crankshaft. Note the alignment of the crankshaft woodruff key.
   ⚠Do not use impact tools on crankshaft bolt as this can damage the crankshaft sensor reluctor ring.
   Torque spec

   Crankshaft pulley bolt (stretch, replace)90 Nm (66 lb-ft)
3. 3

   Remove valve covers
   Disconnect ignition coils and fuel injector connectors on both banks. Remove ignition coils. Disconnect PCV hoses and any vacuum lines attached to valve covers. Remove valve cover bolts in reverse of tightening sequence. Carefully remove both valve covers and gaskets. Clean all gasket surfaces thoroughly.
4. 4

   Remove engine mount and position engine
   Remove the right side engine mount (passenger side). Use the engine support bar to slightly raise and position the engine for optimal access to timing cover. Ensure engine is stable and well-supported before proceeding.
5. 5

   Remove timing cover
   Remove all timing cover bolts, noting the different lengths and positions. There are both 6mm and 8mm bolts in specific locations. Carefully separate the timing cover from the engine block using a plastic pry tool. Do not damage the sealing surfaces. Remove and discard the old gasket and front crankshaft seal.
   ⚠Do not pry between aluminum sealing surfaces as damage will cause oil leaks.
6. 6

   Verify and mark timing alignment
   Rotate the crankshaft to TDC cylinder 1 (compression stroke). Verify timing marks on all camshaft sprockets align with the cylinder head markings. The crankshaft keyway should point upward. Install timing pins through the camshaft sprockets and into the cylinder heads to lock timing position. Take detailed photographs of all chain routing and sprocket positions.
   ⚠️Verify all timing marks three times before proceeding. Incorrect reassembly will destroy the engine.
7. 7

   Remove timing chains
   Remove the timing chain tensioners by compressing them and removing the mounting bolts. Remove the tensioner arms. Remove both camshaft sprocket bolts using the camshaft holding tool to prevent rotation. Remove the camshaft sprockets. Remove the primary and secondary timing chains from the crankshaft sprocket. Keep chains organized and note routing paths.
8. 8

   Remove and inspect old timing chain guides
   Remove the timing chain guide bolts from all guides (primary and secondary chain guides). Carefully extract the worn guides from the engine. Inspect all guide mounting surfaces for damage or wear. Check the crankshaft sprocket and intermediate sprockets for excessive wear or damage. Replace if necessary.
   ℹ️Common failure points are the primary chain guides. Inspect carefully for cracks, deep grooves, or missing material.
   Torque spec

   Chain guide bolts12 Nm (9 lb-ft)
9. 9

   Install new timing chain guides
   Install the new primary timing chain guides into their mounting positions. Install the secondary chain guides. Install and tighten all guide mounting bolts to specification. Ensure guides are properly seated and aligned in their channels with no interference to chain routing paths.
   Torque spec

   Chain guide bolts12 Nm (9 lb-ft)
10. 10

    Install timing chains and sprockets
    Route the primary timing chain over the crankshaft sprocket. Install the secondary chains onto the intermediate sprockets following the marked routing. Install the camshaft sprockets with chains engaged, aligning timing marks. Loosely install camshaft sprocket bolts. Verify all timing marks align correctly with timing pins still installed.
11. 11

    Install tensioners and verify timing
    Compress new timing chain tensioners and lock them in the compressed position using pins or clips. Install tensioner arms and new tensioners, tightening mounting bolts to specification. Remove tensioner locking pins to apply tension. Using the camshaft holding tool, tighten camshaft sprocket bolts to specification. Remove timing alignment pins from camshafts.
    ⚠Ensure tensioners are properly compressed before installation or chains will have insufficient tension.
12. 12

    Verify timing and chain operation
    Manually rotate the crankshaft two complete revolutions clockwise using a socket on the crankshaft bolt. Stop at TDC cylinder 1. Verify all timing marks realign perfectly. Attempt to reinstall timing pins - they should slide in easily if timing is correct. Check that all chains have proper tension and no slack.
    ⚠️If timing marks do not realign after two rotations, disassemble and correct the timing. Do not proceed.
13. 13

    Install timing cover
    Clean all timing cover and engine block sealing surfaces with gasket remover and scraper. Apply a thin bead of RTV silicone at the engine block to oil pan joints and the cylinder head to block corners. Install new timing cover gasket. Position timing cover carefully onto engine block. Install all timing cover bolts finger-tight, then tighten in the specified sequence to proper torque values based on bolt size.
    ℹ️RTV must be applied sparingly. Excess sealant can block oil passages.
14. 14

    Install crankshaft pulley
    Install new crankshaft front seal into timing cover if not already done. Ensure crankshaft woodruff key is properly seated. Install the crankshaft pulley, aligning with the key. Install the crankshaft pulley bolt and tighten to specification using the holding tool to prevent rotation.
    Torque spec

    Crankshaft pulley bolt (stretch, replace)90 Nm (66 lb-ft)
15. 15

    Reinstall remaining components
    Reinstall the engine mount. Install new valve cover gaskets and reinstall valve covers, tightening bolts in the proper sequence to specification. Reconnect all electrical connectors, vacuum lines, and PCV hoses. Reinstall ignition coils. Reinstall A/C compressor and power steering pump. Install belt tensioner and serpentine belt. Reinstall splash shields and wheels.

Reassembly

1. Fill engine with 6 quarts of Motorcraft 0W-20 synthetic oil and install new oil filter
2. Refill cooling system with 13 quarts of Motorcraft Orange coolant and bleed air from system
3. Reconnect negative battery terminal
4. Reinstall engine cover and air intake assembly
5. Double-check that all connectors, hoses, and fasteners have been reinstalled

Verification

• Start engine and listen carefully for any abnormal timing chain noise or rattling
• Allow engine to idle and verify no oil leaks from timing cover or valve covers
• Monitor oil pressure gauge - should reach normal operating pressure within seconds
• Check for coolant leaks and verify proper operating temperature
• Perform a test drive and verify smooth operation under load and acceleration
• Recheck oil and coolant levels after test drive, top off if necessary
• Scan for any diagnostic trouble codes related to camshaft or crankshaft position sensors

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