This procedure covers the removal and replacement of the knock sensor(s) on the 2011-2014 Ford F-150 5.0L V8 Coyote engine, which requires removing the intake manifold for access.

Warnings

Tools required

Parts

• Knock sensor × 1 — Use OEM Motorcraft DY1275 or equivalent
• Intake manifold gasket set × 1 — Use OEM specification
• Throttle body gasket × 1 — Use OEM specification

Fluids

• Motorcraft Orange Coolant — 2 qt

Preparation

1. Ensure engine is completely cool to the touch
2. Disconnect negative battery cable and wait 10 minutes for airbag system to discharge
3. Relieve fuel system pressure by removing fuel pump fuse and starting engine until it stalls
4. Place drain pan under radiator and partially drain coolant to below intake manifold level
5. Remove engine cover by pulling upward on front clips
6. Take photos of vacuum line and electrical connector routing for reference during reassembly

Procedure

1. 1

   Remove air intake system
   Loosen clamp at throttle body and disconnect air intake tube. Disconnect mass airflow sensor electrical connector. Remove entire air filter housing assembly by releasing clips and lifting out. Disconnect PCV hose from valve cover.
2. 2

   Disconnect throttle body and accessories
   Disconnect throttle body electrical connector. Remove throttle body mounting bolts and set throttle body aside with coolant hoses still attached. Disconnect brake booster vacuum line at intake manifold.
3. 3

   Remove upper engine wiring and accessories
   Disconnect all ignition coil connectors (8 total). Remove ignition coils by removing single bolt from each and pulling straight up with twisting motion. Disconnect fuel injector wiring harness connectors on both sides. Disconnect remaining sensors on intake manifold including MAP sensor and purge valve. Label all connections if necessary.
4. 4

   Disconnect fuel system
   Disconnect fuel supply line at fuel rail using quick-disconnect tool or by depressing tabs. Have shop towel ready to catch residual fuel. Disconnect fuel rail pressure sensor connector.
5. 5

   Remove PCV system components
   Disconnect PCV valve from driver side valve cover. Remove PCV hose assembly from intake manifold. Disconnect crankcase ventilation tube from passenger side valve cover.
6. 6

   Remove intake manifold mounting bolts
   Remove the intake manifold mounting bolts in reverse order of tightening sequence (work from outside to inside). There are 10 bolts total. Keep bolts organized by position for reassembly.
   Torque spec

   Mounting Bolts59 Nm (44 lb-ft)
7. 7

   Remove intake manifold assembly
   Carefully lift intake manifold straight up and away from engine. The manifold may stick to gaskets initially - gently work it free without prying against sealing surfaces. Set manifold on clean work surface with mounting surface facing up to protect it.
8. 8

   Access and remove knock sensor
   Locate knock sensor in the valley between cylinder banks (typically on driver side of engine block). Disconnect knock sensor electrical connector by releasing lock tab. Remove knock sensor using appropriate socket (typically 22mm deep socket), turning counterclockwise.
   ⚠Note orientation of sensor before removal. Sensor must be reinstalled in same position.
   Torque spec

   Knock Sensor20 Nm (15 lb-ft)
9. 9

   Clean mounting surfaces
   Thoroughly clean intake manifold gasket mating surfaces on cylinder heads and engine block using plastic gasket scraper. Remove all old gasket material completely. Clean knock sensor mounting bore with clean shop towel. Wipe valley area clean of any debris or coolant.
10. 10

    Install new knock sensor
    Install new knock sensor by hand into mounting bore, ensuring threads start cleanly. Tighten to specified torque using torque wrench. Do not over-tighten as this will damage sensor and cause false knock readings. Reconnect electrical connector ensuring positive lock engagement.
    ⚠Proper torque is CRITICAL. Over-tightening damages sensor piezoelectric element. Under-tightening causes incorrect readings.
    Torque spec

    Knock Sensor20 Nm (15 lb-ft)
11. 11

    Install new intake manifold gaskets
    Position new intake manifold gaskets onto cylinder heads. Ensure alignment pins (if equipped) are properly seated. Gaskets should lay flat without any curling or damage. Do not use gasket sealer unless specifically required by gasket manufacturer.
    ⚠Verify gaskets are correct side up - typically marked 'TOP' or 'UP' on gasket surface.
12. 12

    Reinstall intake manifold
    Carefully lower intake manifold into position, aligning all bolt holes. Ensure gaskets remain properly positioned and do not shift during installation. Hand-start all 10 mounting bolts before tightening any. Tighten bolts in proper sequence (inside to outside, alternating side to side) to specified torque in multiple passes.
    Torque spec

    Mounting Bolts59 Nm (44 lb-ft)
13. 13

    Reconnect fuel and PCV systems
    Reconnect fuel supply line to fuel rail until it clicks into place. Tug gently to verify connection. Reconnect fuel rail pressure sensor. Reinstall PCV valve and all crankcase ventilation hoses to valve covers and intake manifold connections.
14. 14

    Reinstall ignition coils and wiring
    Reinstall all 8 ignition coils into spark plug wells, ensuring they seat completely. Install coil mounting bolts and tighten. Reconnect all ignition coil electrical connectors. Reconnect fuel injector wiring harness on both banks. Reconnect all intake manifold sensors including MAP sensor and purge valve.
15. 15

    Reinstall throttle body and air intake
    Install throttle body with new gasket and tighten mounting bolts evenly. Reconnect throttle body electrical connector. Reconnect brake booster vacuum line. Reinstall air filter housing assembly and connect air intake tube to throttle body, tightening clamp securely. Reconnect mass airflow sensor connector.

Reassembly

1. Refill cooling system with Motorcraft Orange Coolant to proper level
2. Reconnect negative battery cable
3. Reinstall fuel pump fuse
4. Double-check all electrical connections are secure and all hoses are properly connected
5. Reinstall engine cover

Verification

• Prime fuel system by cycling ignition on/off 3-4 times without starting engine
• Start engine and check for fuel leaks at fuel rail connection
• Check for coolant leaks around intake manifold gaskets
• Allow engine to reach operating temperature and verify no coolant leaks develop
• Verify no vacuum leaks by checking for smooth idle (no rough running or high idle)
• Use scan tool to verify knock sensor is reading properly and no diagnostic trouble codes are present
• Test drive vehicle and verify no check engine light illuminates and engine performs normally under acceleration

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