Valve Cover Gasket - Single

This procedure covers the replacement of the valve cover gasket on the 2014-2019 Toyota Corolla 1.8L I4 engine to repair oil leaks from the valve cover area.

Warnings

Tools required

Parts

• Valve cover gasket × 1 — Use OEM specification
• Spark plug tube seals × 4 — Use OEM specification
• PCV valve grommet × 1 — Use OEM specification (if damaged)

Preparation

1. Park vehicle on level surface and engage parking brake
2. Allow engine to cool completely (minimum 2 hours after operation)
3. Disconnect negative battery terminal using 10mm socket
4. Remove engine cover by pulling upward on retaining clips

Procedure

1. 1

   Remove ignition coils
   Disconnect the electrical connector from each ignition coil by pressing the release tab. Remove the single 10mm bolt securing each ignition coil. Pull each coil straight up and out of the spark plug tube. Set aside in order to maintain cylinder position.
2. 2

   Remove PCV hoses and connections
   Disconnect the PCV hose from the valve cover by releasing the spring clamp or pressing the quick-connect release. Disconnect any breather hoses attached to the valve cover. Note the routing for reassembly.
   ℹ️Take photos of hose routing before disconnection to ensure correct reinstallation.
3. 3

   Disconnect wiring harness clips
   Release any wiring harness clips or brackets attached to the valve cover. The harness typically runs across the top of the valve cover and is secured with plastic clips. Gently move the harness aside to provide access to all valve cover bolts.
4. 4

   Remove valve cover bolts
   Remove all valve cover bolts using a 10mm socket. There are typically 9 bolts securing the valve cover. Remove bolts in reverse of the tightening sequence (outside to center). Keep bolts organized as they may be different lengths.
   ⚠Note the location of any different length bolts or bolts with integrated washers for correct reinstallation.
   Torque spec

   Valve Cover Bolts10 Nm (7 lb-ft)
5. 5

   Remove valve cover
   Gently tap the valve cover with a rubber mallet or use a plastic pry tool to break the gasket seal. Lift the valve cover straight up and away from the cylinder head. Avoid prying against the sealing surfaces.
6. 6

   Remove old spark plug tube seals
   Use a small pick or flathead screwdriver to carefully extract the old spark plug tube seals from the valve cover. There are four seals, one for each spark plug tube. Inspect the tubes in the cylinder head for any oil accumulation.
   ⚠Be careful not to drop debris into the spark plug tubes. Cover tubes with clean rags if necessary.
   Torque spec

   Spark Plug Tube Seals12 Nm (9 lb-ft)
7. 7

   Clean all sealing surfaces
   Use a plastic gasket scraper to remove all old gasket material from both the valve cover and cylinder head sealing surfaces. Clean surfaces thoroughly with brake cleaner and lint-free rags. Ensure no residue, oil, or debris remains on sealing surfaces. Inspect for any damage or warping.
   ⚠Ensure no debris falls into the engine. Cover open areas with clean rags during cleaning.
8. 8

   Install new spark plug tube seals
   Lightly lubricate new spark plug tube seals with clean engine oil. Press the seals firmly into the valve cover by hand until fully seated. Ensure each seal sits flush and is properly positioned in its groove.
   Torque spec

   Spark Plug Tube Seals12 Nm (9 lb-ft)
9. 9

   Install new valve cover gasket
   Position the new valve cover gasket onto the valve cover. The gasket typically has locating pins or grooves that align with the valve cover. Ensure the gasket is properly seated in all locations and lies flat with no twists or folds.
   ℹ️Do not apply additional sealant unless specified by the gasket manufacturer. Modern gaskets are designed to seal without RTV.
10. 10

    Install valve cover
    Carefully lower the valve cover with gasket onto the cylinder head, ensuring proper alignment with all bolt holes and the spark plug tubes. Verify the gasket remains properly positioned during installation.
11. 11

    Tighten valve cover bolts in sequence
    Install all valve cover bolts finger-tight first. Using a torque wrench, tighten bolts to specification in a cross pattern starting from the center and working outward. Make multiple passes, gradually increasing torque to the final specification to ensure even gasket compression.
    ⚠Overtightening valve cover bolts can warp the cover and cause oil leaks. Use a calibrated torque wrench.
    Torque spec

    Valve Cover Bolts10 Nm (7 lb-ft)
12. 12

    Reinstall PCV and breather hoses
    Reconnect all PCV hoses and breather hoses to the valve cover. Ensure all connections are secure and hose clamps are properly positioned. Replace the PCV valve grommet if it shows any signs of damage or hardening.
13. 13

    Reinstall ignition coils
    Apply a small amount of dielectric grease to the inside of each ignition coil boot. Install each ignition coil into its respective spark plug tube, ensuring proper seating. Install and torque the 10mm retaining bolt for each coil. Reconnect all electrical connectors.
14. 14

    Reinstall wiring harness and engine cover
    Reattach all wiring harness clips and brackets to the valve cover. Verify all connections are secure and wiring is properly routed. Reinstall the engine cover by aligning and pressing down on the retaining clips. Reconnect the negative battery terminal.

Reassembly

1. Double-check that all electrical connectors are fully seated and locked
2. Verify all hoses are properly connected and secured with clamps
3. Ensure no tools or rags were left in the engine compartment

Verification

• Start the engine and allow it to idle for 2-3 minutes while observing the valve cover area for any oil leaks
• Check for any unusual noises or rough idle that might indicate a problem with ignition coil installation
• Rev the engine to 2500-3000 RPM briefly and recheck for leaks around the valve cover perimeter
• After the first drive cycle, recheck the valve cover area for any seepage and verify all connections remain secure
• Monitor oil consumption and check for leaks after 100-200 miles of operation

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