Timing Chain

Complete timing chain replacement procedure for the 2009 Aston Martin DB9 6.0L V12, including front-end disassembly, engine cover removal, and timing system replacement with critical alignment procedures.

Warnings

Tools required

Parts

• Timing chain kit (includes chains, guides, tensioners) × 1 — Use OEM Aston Martin specification
• Front crankshaft seal × 1 — Use OEM specification
• Timing cover gasket set × 1 — Use OEM specification
• Camshaft position sensor O-rings × 4 — Use OEM specification
• Valve cover gaskets × 2 — Use OEM specification
• Thermostat housing gaskets × 2 — Use OEM specification
• Coolant hoses (if damaged during removal) × 1 — Inspect and replace as needed
• Engine oil filter × 1 — Use OEM specification
• Accessory belt set × 1 — Use OEM specification
• Crankshaft pulley bolt (if TTY specification) × 1 — Use OEM specification

Fluids

• 5W-30 engine oil — 10.5 qt
• OAT 50/50 coolant — 10.5 qt
• CHF 11S power steering fluid — 1.2 qt
• R-134a AC refrigerant

Preparation

1. Park vehicle on level surface and engage parking brake. Place wheel chocks at rear wheels.
2. Disconnect negative battery terminal and wait 15 minutes for airbag system capacitor discharge.
3. Remove engine undertray panels using appropriate Torx fasteners.
4. Drain engine coolant completely from both radiator and block drain points into suitable containers.
5. Drain engine oil and remove oil filter.
6. Have AC system professionally recovered by certified technician if condenser or lines require removal.
7. Label all electrical connectors, vacuum lines, and coolant hoses with tape and marker before disconnection.
8. Print or download wiring diagrams and timing mark specifications for reference during reassembly.
9. Organize workspace with labeled containers for fasteners by component (e.g., 'front bumper', 'timing cover', 'valve covers').

Procedure

1. 1

   Remove Front-End Components
   Remove front bumper cover by releasing lower grille clips and removing Torx fasteners at wheel well liners and upper mounting points. Disconnect fog light connectors if equipped. Remove radiator grille assembly. Remove hood latch mechanism and support bracket. Disconnect headlight electrical connectors and remove headlight assemblies to access radiator support mounting points. This provides necessary clearance for radiator and fan assembly removal.
2. 2

   Remove Cooling System Components
   Disconnect upper and lower radiator hoses at radiator. Disconnect transmission cooler lines at radiator (automatic transmission) and cap openings to prevent contamination. Remove electric cooling fan assemblies by disconnecting electrical connectors and removing mounting fasteners. Remove radiator by lifting vertically after releasing lower mounting bushings. Remove coolant expansion tank and set aside. Disconnect heater hoses at firewall connections and label for reinstallation.
3. 3

   Remove Accessory Drive System
   Remove serpentine belt by rotating tensioner in the release direction with a breaker bar (verify direction per factory service manual) and sliding belt off pulleys. Document belt routing before removal. Remove power steering pump with lines attached and secure to body with wire (do not disconnect lines). Remove AC compressor mounting bolts and secure compressor to body without disconnecting refrigerant lines. Remove alternator and bracket assembly. Remove idler pulleys and tensioner assemblies, noting location of each component for correct reinstallation.
4. 4

   Remove Intake Manifold and Fuel System Components
   Relieve fuel system pressure by removing fuel pump fuse and running engine until it stalls, then cranking for 5 seconds. Disconnect fuel supply and return lines at fuel rail using appropriate quick-disconnect tools. Disconnect throttle body electrical connector and vacuum lines. Remove intake plenum by removing mounting fasteners working from center outward. Disconnect fuel injector electrical connectors and label by cylinder position. Remove fuel rails with injectors attached. Remove intake manifold runners, noting gasket condition and any alignment dowels. Cover exposed cylinder head ports with clean shop towels to prevent debris entry.
5. 5

   Remove Valve Covers and Upper Engine Components
   Disconnect ignition coil connectors and remove all ignition coils from spark plug wells (verify coil count and arrangement against factory service documentation). Remove valve cover fasteners in reverse of tightening sequence (outside to inside pattern). Carefully remove both valve covers, noting any harness brackets or ground points attached. Inspect rocker assemblies and valve train components for wear while exposed. Remove any upper engine harness brackets that will interfere with timing cover access. Remove thermostat housings from both cylinder banks by removing mounting fasteners and disconnecting coolant hoses.
6. 6

   Support Engine and Remove Front Mounts
   Install engine support fixture across inner fender wells or attach engine hoist to lifting eyes on cylinder heads. Take up slack to support engine weight without lifting. Remove front engine mount through-bolts. Remove engine mount brackets from engine block. Remove lower subframe crossmember if necessary for oil pan clearance (remove mounting bolts and lower carefully with jack). The engine must now be safely supported before proceeding with timing cover removal.
7. 7

   Remove Crankshaft Pulley and Harmonic Balancer
   Remove crankshaft pulley center bolt using appropriate socket and breaker bar while holding crankshaft with holding tool installed in flex plate or flywheel. This bolt is extremely tight (torque/angle spec per factory service manual). Install harmonic balancer puller and remove balancer from crankshaft snout. Do not use impact tools or strike balancer with hammer as this can damage crankshaft or balancer. Inspect balancer for rubber deterioration or separation; replace if any damage is present. Remove balancer key from crankshaft keyway and store safely. Note: Remove crankshaft pulley center bolt using appropriate socket and breaker bar while holding crankshaft with holding tool installed in flex plate or flywheel. This bolt is extremely tight (verify exact torque and angle specification against factory service documentation before removal/reinstallation). Note: Remove crankshaft pulley center bolt using appropriate socket and breaker bar while holding crankshaft with holding tool installed in flex plate or flywheel. This bolt is extremely tight; expect significant removal torque (verify exact removal/installation torque and angle against Aston Martin service data).
   Torque spec

   Crankshaft Pulley Bolt180 Nm (133 lb-ft) + 90°
8. 8

   Remove Timing Cover
   Remove oil pan-to-timing cover bolts from underneath vehicle. Remove timing cover mounting bolts, noting different bolt lengths and locations for reinstallation. The timing cover is secured by a number of bolts of varying lengths (verify exact count and locations in the factory service manual). Carefully pry timing cover away from block using plastic pry tools at designated pry points only (do not pry on sealing surfaces). Remove timing cover and gasket. Clean all gasket surfaces thoroughly with plastic scraper and degreaser. Inspect cover for cracks or warping, particularly around bolt holes and seal bore. Note: The timing cover is secured by multiple bolts of varying sizes (verify exact bolt count and lengths against factory service documentation).
9. 9

   Rotate Engine to TDC and Lock Timing
   Rotate crankshaft clockwise (viewed from front) using socket on crankshaft snout until cylinder 1 is at Top Dead Center on compression stroke. Align timing marks on crankshaft sprocket with mark on engine block. Verify all camshaft timing marks align with their respective marks on cylinder heads. Install Aston Martin camshaft locking tools to lock all four camshafts (two per bank) in position per the factory tool procedure. Install crankshaft holding tool to prevent rotation. Do NOT proceed until all timing tools are properly installed and verified. Take photographs of all timing mark positions for reference.
10. 10

    Remove Timing Chain Tensioners and Guides
    Remove timing chain tensioner mounting bolts and carefully extract tensioners. Note the orientation of each tensioner (left bank, right bank) as they may not be interchangeable. Inspect tensioners for proper operation by pressing plunger; it should extend smoothly with spring pressure. Remove timing chain guide mounting bolts and remove guides. The V12 typically has multiple guides per bank including upper fixed guides and lower pivoting guides. Keep all guides organized by bank and position for comparison with new parts.
    Torque spec

    Timing Chain Tensioner25 Nm (18 lb-ft)

    Timing Chain Guide Bolts10 Nm (7 lb-ft)
11. 11

    Remove Timing Chains and Sprockets
    Remove camshaft sprocket bolts while camshafts are locked with holding tools. Remove camshaft sprockets from camshaft noses. Remove timing chains from sprockets and crankshaft sprocket. Note routing of chains through guides and around idler sprockets if equipped. Remove crankshaft sprocket using appropriate puller if it does not slide off freely. Inspect all sprocket teeth for wear, chips, or unusual wear patterns. Lay old chains flat and compare length to new chains to verify old chains have stretched (typical indication of needed replacement).
    Torque spec

    Camshaft Sprocket Bolts80 Nm (59 lb-ft)
12. 12

    Inspect and Prepare for Reassembly
    Thoroughly clean all timing chain running surfaces, guides, and sprocket mounting surfaces. Inspect camshaft and crankshaft sprocket mounting surfaces for damage or wear. Check camshaft end play using dial indicator (compare to factory specification in FSM). Verify all timing marks are clearly visible on new sprockets. Inspect cylinder head timing mark surfaces for damage. Remove and inspect front crankshaft seal; replace if any wear is present. Clean timing cover bolt holes in block using thread chaser or tap to ensure proper torque values during reinstallation. Note: Check camshaft end play using dial indicator (verify end play specification against factory service documentation). Note: Check camshaft end play using dial indicator and compare against the OEM camshaft end play specification for the 2009 Aston Martin DB9 6.0L V12 (verify exact range in service manual).
13. 13

    Install New Crankshaft Sprocket and Chains
    Install new crankshaft sprocket onto crankshaft snout, aligning keyway with key. Sprocket should slide on with light hand pressure; if excessive force is required, inspect for burrs or damage. Install new timing chains onto crankshaft sprocket, routing through guide positions per factory service manual diagrams. Ensure chains are routed correctly (inside or outside of guides as applicable). Verify crankshaft is still at TDC position with timing mark aligned before proceeding with camshaft sprocket installation.
14. 14

    Install Camshaft Sprockets
    Install timing chains onto camshaft sprockets before installing sprockets to camshafts. Align camshaft sprockets to camshaft noses, ensuring timing marks on sprockets align with cylinder head reference marks. Install camshaft sprocket bolts finger-tight. Verify all timing marks are correctly aligned: crankshaft mark at TDC, all four camshaft marks at their respective TDC positions, and chains properly tensioned over sprockets. With camshaft locking tools still installed, torque camshaft sprocket bolts in sequence per specifications. Remove camshaft locking tools and rotate engine two full revolutions by hand, then reinstall locking tools to verify timing marks still align correctly.
    Torque spec

    Camshaft Sprocket Bolts80 Nm (59 lb-ft)
15. 15

    Install Timing Chain Guides and Tensioners
    Install new timing chain guides in their respective positions, ensuring pivot guides are oriented correctly. Install guide mounting bolts and torque to specification. Install new timing chain tensioners after compressing and locking plungers in retracted position using pins or clips provided with tensioners. Install tensioner mounting bolts and torque to specification. Remove tensioner locking pins/clips in the sequence specified by manufacturer (typically outboard tensioners first, then inboard) to allow tensioners to apply pressure to chains. Verify chains have proper tension by checking for excessive slack; chains should have minimal deflection when pressed at midpoint between sprockets.
    Torque spec

    Timing Chain Tensioner25 Nm (18 lb-ft)

    Timing Chain Guide Bolts10 Nm (7 lb-ft)
16. 16

    Install New Front Crankshaft Seal
    Install new front crankshaft seal into timing cover using appropriate seal driver or large socket matching seal outer diameter. Seal should be driven in squarely until flush with timing cover surface or to depth specified by manufacturer. Lubricate seal lip with clean engine oil before timing cover installation to prevent seal damage during initial startup.
17. 17

    Install Timing Cover
    Apply new timing cover gasket or RTV silicone per manufacturer specification to engine block surface. Position timing cover carefully over crankshaft snout, ensuring front seal does not damage seal lip on crankshaft. Install all timing cover bolts finger-tight, noting correct bolt lengths for each position. Torque timing cover bolts in sequence starting from center and working outward in a star pattern to specified torque. Install oil pan-to-timing cover bolts and torque to specification.
    Torque spec

    Timing Cover Bolt12 Nm (9 lb-ft)
18. 18

    Install Harmonic Balancer and Crankshaft Pulley
    Install crankshaft key into keyway. Lubricate crankshaft snout and harmonic balancer bore with clean engine oil. Slide harmonic balancer onto crankshaft, aligning keyway with key. Balancer should slide on with moderate hand pressure; if resistance is excessive, inspect for burrs or misalignment. Install new crankshaft pulley bolt (if TTY specification) or clean and inspect old bolt for reuse. Torque crankshaft pulley bolt to the factory-specified torque, then apply the specified additional angle using an angle gauge (verify both values in the factory service manual). Use crankshaft holding tool to prevent rotation during tightening. Note: Torque crankshaft pulley bolt to the factory-specified torque, then tighten the specified additional angle using an angle gauge (verify both values against factory service documentation). Note: Torque crankshaft pulley bolt to the OEM-specified torque and angle for the 2009 Aston Martin DB9 6.0L V12 (verify exact torque value and angle sequence against Aston Martin service data before final tightening).
    Torque spec

    Crankshaft Pulley Bolt180 Nm (133 lb-ft) + 90°
19. 19

    Reinstall Engine Mounts and Remove Support
    Raise subframe crossmember back into position if removed and install mounting bolts. Install engine mount brackets to engine block. Install front engine mount through-bolts and torque to specification. Carefully lower engine onto mounts using support fixture or hoist, verifying proper seating. Remove engine support fixture or hoist.
20. 20

    Reinstall Valve Covers and Upper Engine Components
    Install new valve cover gaskets onto valve covers. Position valve covers onto cylinder heads, ensuring gaskets remain properly seated. Install valve cover bolts and torque in sequence from center outward to prevent gasket distortion. Reinstall thermostat housings with new gaskets and torque mounting bolts. Reinstall ignition coils into spark plug wells and connect electrical connectors. Reconnect all upper engine harness brackets and ground points.
21. 21

    Reinstall Intake Manifold and Fuel System
    Remove shop towels from cylinder head ports. Install intake manifold runners with new gaskets, ensuring alignment dowels are properly seated. Torque intake manifold bolts in sequence from center outward. Install fuel rails with injectors and torque mounting bolts. Reconnect fuel injector electrical connectors per labels. Install intake plenum with new gaskets and torque mounting bolts. Reconnect throttle body electrical connector and vacuum lines. Reconnect fuel supply and return lines using new O-rings.
22. 22

    Reinstall Accessory Drive Components
    Install alternator and bracket assembly. Install AC compressor to mounting brackets and torque bolts. Install power steering pump and torque mounting bolts. Install idler pulleys and tensioner assemblies. Install serpentine belt per documented routing. Verify belt is properly seated on all pulleys and tensioner applies proper tension.
23. 23

    Reinstall Cooling System and Front-End Components
    Install radiator into position and secure lower mounting bushings. Install electric cooling fan assemblies and connect electrical connectors. Reconnect transmission cooler lines at radiator. Reconnect upper and lower radiator hoses. Install coolant expansion tank. Reconnect heater hoses at firewall. Install headlight assemblies and connect electrical connectors. Install hood latch mechanism and support bracket. Install radiator grille assembly. Install front bumper cover and secure all mounting points and clips. Reconnect fog light connectors if equipped.
24. 24

    Fill Fluids and Final Checks
    Install new engine oil filter and fill engine with the factory-specified oil capacity and viscosity (verify quantity and grade in the owner's manual/FSM). Fill cooling system with the factory-specified coolant type and quantity (verify in FSM) using vacuum fill method if available, or fill slowly and burp system to remove air pockets. Top off power steering fluid reservoir with the Aston Martin-specified power steering fluid to proper level (verify fluid type in FSM). Reconnect negative battery terminal. Perform final visual inspection of all connections, fasteners, and components. Check for any tools or parts left in engine bay. Note: Fill cooling system with the factory-specified quantity of Aston Martin-approved coolant using vacuum fill method if available, or fill slowly and burp system to remove air pockets (verify capacity and coolant specification against factory service documentation). Note: Install new engine oil filter and fill engine with the factory-specified quantity of Aston Martin-approved engine oil of the correct viscosity (verify capacity and grade against factory service documentation). Note: Install new engine oil filter and fill engine with 5W-40 fully-synthetic engine oil meeting Aston Martin/Ford specification; verify exact capacity (approximately 11-12 quarts) against the factory service manual. Note: Fill cooling system with the OEM-specified volume of Aston Martin-approved coolant mixed 50/50 using vacuum fill method if available, or fill slowly and burp system to remove air pockets (verify exact capacity against service manual).

Reassembly

1. Torque all fasteners to specified values using calibrated torque wrench.
2. Install all components in reverse order of removal, referencing photographs taken during disassembly.
3. Replace all single-use fasteners, gaskets, and seals with new parts.
4. Verify timing chain alignment multiple times before final timing cover installation.
5. Ensure all electrical connectors are fully seated with locking tabs engaged.
6. Double-check serpentine belt routing against documented configuration before starting engine.

Verification

• Perform visual inspection for fluid leaks, particularly at timing cover, valve covers, and coolant connections.
• Start engine and verify oil pressure within 5 seconds of startup. If oil pressure warning remains illuminated, shut down immediately and investigate.
• Check for unusual engine noises, particularly rattling or knocking that could indicate timing chain or tensioner issues.
• Verify engine idles smoothly without misfires. Check for diagnostic trouble codes using scan tool.
• Bring engine to operating temperature and verify cooling fans cycle properly and no coolant leaks develop.
• After initial warm-up and cool-down cycle, recheck coolant level and top off as necessary.
• Test drive vehicle and verify smooth acceleration, proper power delivery, and no warning lights.
• After 100 miles of driving, recheck all fluid levels and perform visual inspection for leaks.
• Consider performing compression test and leak-down test if any concerns exist about valve timing or engine condition.

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