Valve Cover Gasket - Single

This procedure covers removal and replacement of the valve cover gasket on the 2016-2021 Honda Civic 1.5L turbocharged engine to address oil leaks from the valve cover mating surface.

Warnings

Tools required

Parts

• Valve cover gasket × 1 — Honda 12030-5AA-A00 or equivalent
• Spark plug tube seals × 4 — Honda 12342-5AA-A00 or equivalent

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 and wait 3 minutes for system discharge
4. Remove engine cover by pulling upward on all four corners

Procedure

1. 1

   Remove ignition coils
   Disconnect all four ignition coil electrical connectors by pressing the release tab and pulling straight up. Remove the single 10mm bolt from each ignition coil. Pull each coil straight up with a twisting motion to remove from spark plug tubes.
2. 2

   Remove spark plugs
   Use compressed air to blow out any debris from around the spark plug wells. Remove all four spark plugs using a spark plug socket. Inspect plugs for condition and set aside for reinstallation or replacement.
3. 3

   Disconnect PCV hose and breather hose
   Locate the PCV hose on the driver side of the valve cover and the breather hose on the passenger side. Squeeze the hose clamps and slide them back, then twist and pull the hoses off their fittings on the valve cover.
   ℹ️Mark hose positions if necessary to ensure correct reinstallation.
4. 4

   Disconnect wiring harness clips
   Remove any wiring harness clips or brackets attached to the valve cover. On this engine, there are typically 2-3 harness clips that snap onto studs on the valve cover. Use a small flathead screwdriver to carefully pry them off if needed.
5. 5

   Remove valve cover bolts
   Remove all valve cover bolts in reverse of the tightening sequence (outside to inside pattern). There are typically 11 bolts total. Keep track of bolt locations as some may be different lengths. Gently tap the valve cover with a plastic mallet if it sticks to the cylinder head.
   ⚠Do not pry between the valve cover and cylinder head gasket surfaces as this can cause damage requiring resurfacing.
   Torque spec

   Valve Cover Bolts10 Nm (7 lb-ft)
6. 6

   Remove valve cover
   Carefully lift the valve cover straight up and off the cylinder head. Tilt it slightly toward the passenger side to clear any obstacles. Set it on a clean work surface with the gasket surface facing up.
7. 7

   Remove old spark plug tube seals
   Remove the four rubber spark plug tube seals from the valve cover. These are press-fit and can be carefully pried out using a small flathead screwdriver or picked out with needle-nose pliers. Inspect the tubes in the cylinder head for any oil accumulation.
   Torque spec

   Spark Plug Tube Seals12 Nm (9 lb-ft)
8. 8

   Clean gasket surfaces
   Remove all old gasket material from both the valve cover and cylinder head mating surfaces using a plastic gasket scraper. Clean surfaces thoroughly with brake cleaner and lint-free towels. Ensure no debris falls into the engine. Inspect both surfaces for any damage, warping, or cracks.
   ⚠Stuff clean shop towels into the cam chain cavity and lifter valley to prevent debris from entering the engine. Remove towels before reassembly.
9. 9

   Install new spark plug tube seals
   Press new spark plug tube seals into the valve cover by hand until they are fully seated. Ensure they are positioned correctly and sit flush in their bores. Apply a small amount of engine oil to the seal lips.
   Torque spec

   Spark Plug Tube Seals12 Nm (9 lb-ft)
10. 10

    Install new valve cover gasket
    Position the new valve cover gasket into the groove in the valve cover. Ensure the gasket is fully seated in the groove all the way around and that the spark plug tube seals align with their openings. The gasket should snap into place and stay positioned without adhesive.
    ℹ️Do not use RTV sealant or gasket adhesive unless specified by Honda for your specific engine build date. The gasket is designed to seal without additional sealant.
11. 11

    Install valve cover
    Verify all shop towels have been removed from the engine. Carefully position the valve cover onto the cylinder head, ensuring the gasket remains in place and all bolt holes align. Insert all valve cover bolts finger-tight first.
12. 12

    Torque valve cover bolts in sequence
    Tighten the valve cover bolts to specification following the numbered sequence stamped on the valve cover (typically starting from the center and working outward in a spiral pattern). Use a torque wrench and tighten in two stages: first to 5 Nm, then to final specification.
    ⚠Over-tightening valve cover bolts can crack the cover or distort the gasket surface, causing leaks. Always use a torque wrench.
    Torque spec

    Valve Cover Bolts10 Nm (7 lb-ft)
13. 13

    Reinstall spark plugs
    Apply a small amount of anti-seize compound to the spark plug threads. Install spark plugs by hand until finger-tight, then torque to specification using a torque wrench. Do not overtighten.
    ⚠Cross-threading spark plugs in aluminum heads can cause expensive damage. Always start threading by hand.
14. 14

    Reinstall ignition coils and connections
    Install ignition coils into the spark plug tubes, ensuring they seat fully. Install and torque the ignition coil bolts. Reconnect all four ignition coil electrical connectors until they click into place.
15. 15

    Reconnect hoses and harnesses
    Reconnect the PCV hose and breather hose to the valve cover, ensuring hose clamps are positioned properly. Reattach all wiring harness clips to the valve cover studs. Reinstall the engine cover by pressing down on all four corners until it clicks into place.

Reassembly

1. Reconnect the negative battery terminal and tighten securely
2. Do not start the engine immediately; perform verification steps first

Verification

• Visually inspect the valve cover area to ensure all electrical connectors are attached and no tools or parts were left in the engine bay
• Verify all hoses are connected and hose clamps are secure
• Start the engine and allow it to idle for 2-3 minutes while watching for oil leaks around the valve cover gasket
• Rev the engine gently to 2500-3000 RPM several times and recheck for leaks
• After the engine reaches operating temperature, inspect the valve cover gasket area again for any signs of leakage
• Check for proper engine operation and ensure no warning lights are illuminated on the dashboard
• Allow the engine to cool, then recheck valve cover bolt torque after the first drive cycle if desired

More procedures for this vehicle