Timing Chain Tensioner

This procedure replaces the timing chain tensioners on the 5.0L Coyote V8 engine to restore proper timing chain tension and eliminate rattling noise.

Warnings

Tools required

Parts

• Timing chain tensioners (left and right) × 2 — Ford BR3Z-6K254-B or equivalent
• Timing cover gasket set × 1 — Use OEM specification
• Valve cover gaskets (left and right) × 2 — Use OEM specification
• Valve cover bolt grommets × 20 — Use OEM specification
• Crankshaft front seal × 1 — Use OEM specification
• Engine oil and filter × 1 — Motorcraft FL-820-S or equivalent
• Coolant × 1 — Motorcraft Orange Coolant

Fluids

• Motorcraft 5W-20 Synthetic Blend — 7.5 qt
• Motorcraft Orange Coolant — 3 qt

Preparation

1. Park vehicle on level surface and engage parking brake
2. Disconnect negative battery cable and wait 10 minutes for airbag system discharge
3. Remove engine cover and air intake assembly
4. Drain engine oil and coolant into appropriate containers
5. Remove radiator upper hose and cooling fan assembly
6. Remove accessory drive belt and tensioner
7. Support engine from above using engine support bar or hoist attached to lifting eyes
8. Remove front motor mount bolts to allow engine tilt if needed
9. Mark all connectors and hoses with tape for correct reassembly

Procedure

1. 1

   Remove valve covers
   Disconnect ignition coils and set aside. Remove PCV hoses and wiring from both valve covers. Remove valve cover bolts in reverse of tightening sequence (outside to inside). Carefully lift valve covers off and inspect gasket condition. Clean all gasket surfaces thoroughly with plastic scraper, being careful not to gouge aluminum surfaces.
2. 2

   Remove crankshaft pulley
   Remove crankshaft pulley bolt by holding crankshaft with holding tool. This bolt is very tight and requires significant force. Once bolt is removed, use pulley puller to remove harmonic balancer from crankshaft. Mark pulley orientation before removal for reinstallation reference.
3. 3

   Rotate engine to TDC cylinder #1
   Rotate crankshaft clockwise using socket on crankshaft snout until timing marks align. The crankshaft keyway should point upward at 12 o'clock. Verify both camshaft lobes for cylinder #1 are pointing outward (base circle). Do not proceed unless engine is correctly positioned at TDC compression stroke cylinder #1.
4. 4

   Remove timing cover
   Remove oil pan-to-timing cover bolts from underneath vehicle. Remove all timing cover bolts noting different lengths and positions. There are both 8mm and 10mm bolts that must be tracked separately. Carefully pry timing cover away from block using plastic pry tools only. Remove and discard old gasket and clean all sealing surfaces thoroughly with plastic scraper and brake cleaner.
5. 5

   Install camshaft locking tools
   With engine at TDC, install Ford camshaft alignment tool 303-1248 or equivalent across rear of both camshafts. Tools should slide into slots on camshaft flats easily. If not, engine is not at proper TDC position. These tools MUST remain in place throughout all timing chain work to prevent valve-to-piston contact.
   ⚠️Do not proceed without cam locking tools properly installed. Engine damage will result from cam movement.
6. 6

   Mark and verify timing chain position
   Before removing any components, verify timing marks on camshaft sprockets align with cylinder head surfaces and crankshaft sprocket mark aligns with block mark. Take multiple photos for reference. Use paint marker to mark chain position on all sprockets. Count and document the number of links between timing marks.
7. 7

   Remove old timing chain tensioners
   Working on one side at a time, remove timing chain tensioner bolt and extract tensioner. Note the position and orientation of each tensioner. The right (passenger) and left (driver) tensioners are different parts. Remove timing chain guide bolts and guides if replacing guides or if access is needed.
   ⚠Timing chains will be loose once tensioners are removed. Ensure cam locking tools are secure.
8. 8

   Inspect timing chains and guides
   With tensioners removed, carefully inspect timing chains for wear, stretching, or damaged links. Check all guide rails for scoring, cracking, or excessive wear grooves. Inspect camshaft and crankshaft sprocket teeth for wear. Replace chains and guides if any damage is found. This is the ideal time to replace chains if they show any wear.
9. 9

   Prepare new tensioners
   Remove new tensioners from packaging. Using a small drill bit or paper clip, compress tensioner plunger fully and insert retaining pin through hole to keep tensioner compressed. This pin will be removed after installation to activate tensioner. Verify tensioners are correct left and right versions.
   ℹ️Tensioners must be installed compressed with retaining pins in place or they will extend prematurely.
10. 10

    Install timing chain guides (if removed)
    Position timing chain guides back into their original locations. Install guide bolts and tighten to specification using torque wrench. Guides must be flush against engine block mounting surfaces before tightening.
11. 11

    Install new timing chain tensioners
    With tensioner plungers compressed and pins installed, position new tensioners into mounting holes. Install tensioner bolts and tighten to specification. Ensure tensioners are fully seated before tightening. Do not remove retaining pins yet.
12. 12

    Release tensioners and verify timing
    Remove retaining pins from both tensioners to activate them. Listen for tensioner plungers extending against chains. Verify all timing marks still align correctly. Carefully remove camshaft locking tools and slowly rotate engine two complete revolutions by hand using socket on crankshaft. Reinstall cam locking tools and verify they still fit correctly at TDC. Timing marks must realign perfectly.
    ⚠️If timing marks do not realign after rotation, do not start engine. Disassemble and correct timing immediately.
13. 13

    Reinstall timing cover
    Clean all gasket surfaces with brake cleaner and allow to dry. Apply thin bead of RTV silicone to block surface at oil pan junction points. Position new timing cover gasket and carefully install timing cover. Install all bolts finger tight first, then tighten 8mm bolts to specification in sequence (consult service manual for sequence), followed by remaining bolts. Install oil pan-to-timing cover bolts.
14. 14

    Reinstall crankshaft pulley
    Install new crankshaft front seal into timing cover using seal driver. Lubricate seal lip with clean engine oil. Position harmonic balancer onto crankshaft aligning keyway. Install crankshaft bolt and tighten to specification using holding tool to prevent rotation.
15. 15

    Reinstall valve covers and accessories
    Install new valve cover gaskets and grommets onto valve covers. Position valve covers and install bolts finger tight. Tighten valve cover bolts in sequence from center outward to specification. Reinstall all accessories, drive belt, cooling system components, air intake, and engine cover. Reconnect all electrical connectors and hoses using documentation from disassembly.

Reassembly

1. Reinstall motor mount bolts and remove engine support
2. Refill engine with 7.5 quarts of Motorcraft 5W-20 synthetic blend oil and new filter
3. Refill cooling system with Motorcraft Orange coolant mixed 50/50 with distilled water
4. Reconnect negative battery cable
5. Double-check all connections, bolts, and fluid levels before starting

Verification

• Start engine and verify no unusual noises from timing chain area
• Listen for proper quiet operation with no rattling during cold start
• Allow engine to reach operating temperature and verify no leaks from timing cover or valve covers
• Check for proper oil pressure on instrument cluster
• Verify no check engine light or timing-related fault codes using scan tool
• Road test vehicle under various loads and verify smooth operation with no timing chain noise
• Recheck coolant and oil levels after test drive and top off if necessary

Related trouble codes on this vehicle

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