This procedure covers the replacement of the knock sensor on a 2014-2019 Toyota Corolla with the 1.8L I4 engine, which requires removing the intake manifold to access the sensor mounted on the engine block.

Warnings

Tools required

Parts

• Knock sensor × 1 — Use OEM specification (Toyota 89615-12090 or equivalent)
• Intake manifold gasket × 1 — Use OEM specification
• Throttle body gasket × 1 — Use OEM specification

Fluids

• Toyota Super Long Life Coolant (Pink) — 1.5 qt

Preparation

1. Ensure engine is completely cool to the touch
2. Park vehicle on level ground and engage parking brake
3. Gather all tools and replacement parts
4. Position coolant drain pan under radiator drain
5. Have at least 1.5 quarts of fresh Toyota Super Long Life Coolant available

Procedure

1. 1

   Disconnect battery and drain coolant
   Disconnect the negative battery cable using a 10mm socket. Open the radiator drain cock and drain approximately 1.5 quarts of coolant into a drain pan. This prevents coolant spillage when removing intake manifold components.
2. 2

   Remove engine cover
   Remove the plastic engine cover by pulling upward on the cover to release the four mounting clips. Set aside.
   Torque spec

   Cover Bolts15 Nm (11 lb-ft)
3. 3

   Disconnect air intake system
   Loosen the clamp on the air intake hose at the throttle body using a flathead screwdriver. Disconnect the mass airflow sensor electrical connector. Remove the air intake tube and air filter housing assembly by releasing the mounting clips and lifting out.
4. 4

   Disconnect throttle body and manifold connections
   Disconnect the throttle position sensor electrical connector. Disconnect the coolant hoses from the throttle body (two hoses). Disconnect the PCV hose, brake booster vacuum hose, and purge valve hose from the intake manifold. Label connections if necessary for reassembly.
5. 5

   Remove throttle body
   Remove the four throttle body mounting bolts using a 12mm socket. Carefully separate the throttle body from the intake manifold. Remove and discard the throttle body gasket. Plug the intake manifold opening with a clean rag to prevent debris entry.
   Torque spec

   Mounting Bolts26 Nm (19 lb-ft)
6. 6

   Remove intake manifold stay brackets
   Remove the two intake manifold support brackets located underneath the manifold using a 14mm socket. These brackets connect the manifold to the engine block. Support the manifold by hand during this step.
   Torque spec

   Mounting Bolts26 Nm (19 lb-ft)
7. 7

   Remove intake manifold
   Remove the six intake manifold mounting bolts using a 12mm socket. Work from the outside bolts toward the center. Carefully lift the intake manifold away from the engine. Remove and discard the intake manifold gasket. Clean the mating surfaces on both the cylinder head and manifold using a scraper and parts cleaner.
   ⚠Do not scratch or gouge the aluminum mating surfaces as this will cause vacuum leaks.
   Torque spec

   Gasket Bolts19 Nm (14 lb-ft)
8. 8

   Locate and access knock sensor
   With the intake manifold removed, locate the knock sensor on the right side of the engine block, approximately midway down. It has a single wire connector and is threaded into the block. Use a flashlight to verify location and inspect the sensor and wiring for damage.
9. 9

   Disconnect knock sensor electrical connector
   Press the tab on the knock sensor electrical connector and pull straight out to disconnect. Note the routing of the wiring harness for reinstallation.
10. 10

    Remove knock sensor
    Using a 19mm deep socket, carefully remove the knock sensor from the engine block by turning counterclockwise. The sensor may be tight. Clean the threads in the engine block with a wire brush to remove any corrosion or debris.
    ⚠Do not use an impact wrench on the knock sensor as this can damage the threads in the aluminum block.
11. 11

    Install new knock sensor
    Thread the new knock sensor into the engine block by hand to ensure proper thread engagement. Once hand-tight, use a 19mm deep socket and torque wrench to tighten to specification. Reconnect the electrical connector ensuring it clicks into place.
    ⚠Proper torque is critical for knock sensor function. Overtightening or undertightening will cause incorrect knock detection and possible engine damage.
    Torque spec

    Knock Sensor20 Nm (15 lb-ft)
12. 12

    Install intake manifold with new gasket
    Position the new intake manifold gasket on the cylinder head, aligning all bolt holes. Carefully lower the intake manifold into position. Install all six mounting bolts hand-tight first, then torque in a criss-cross pattern from the center outward to specification.
    Torque spec

    Gasket Bolts19 Nm (14 lb-ft)
13. 13

    Reinstall manifold support brackets
    Reinstall the two intake manifold support brackets underneath the manifold and torque the mounting bolts to specification.
    Torque spec

    Mounting Bolts26 Nm (19 lb-ft)
14. 14

    Reinstall throttle body
    Install a new throttle body gasket. Position the throttle body onto the intake manifold and install the four mounting bolts. Torque to specification in a criss-cross pattern. Reconnect the throttle position sensor connector and both coolant hoses.
    Torque spec

    Mounting Bolts26 Nm (19 lb-ft)
15. 15

    Reconnect remaining components
    Reconnect the PCV hose, brake booster vacuum hose, and purge valve hose to the intake manifold. Reinstall the air intake tube and housing, reconnect the mass airflow sensor connector, and tighten the clamp at the throttle body. Reinstall the engine cover.
16. 16

    Refill coolant and reconnect battery
    Close the radiator drain cock. Add Toyota Super Long Life Coolant to restore the proper level in the radiator and overflow reservoir. Reconnect the negative battery cable. Start the engine and check for coolant leaks at the throttle body hoses.

Reassembly

1. Double-check all electrical connectors are fully seated and locked
2. Verify all vacuum hoses are properly routed and connected
3. Ensure no tools or rags were left in the engine compartment
4. Check coolant level after engine reaches operating temperature and top off if necessary

Verification

• Start the engine and verify it idles smoothly with no vacuum leaks (rough idle or hissing sounds)
• Use an OBD-II scanner to verify no knock sensor codes are present (P0325, P0327, P0328)
• Take a test drive and verify normal engine performance under acceleration
• Check for coolant leaks around throttle body connections after engine reaches operating temperature
• Verify engine operates normally without detonation or pinging under load

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