Valve Cover Gaskets - Both

This procedure covers the replacement of both valve cover gaskets on the 2014-2018 Chevrolet Silverado 1500 with the 5.3L V8 EcoTec3 L83 engine, addressing oil leaks from the valve cover mating surfaces.

Warnings

Tools required

Parts

• Driver side valve cover gasket with grommets × 1 — GM 12639261 or equivalent
• Passenger side valve cover gasket with grommets × 1 — GM 12639262 or equivalent
• Spark plug tube seals (set of 8) × 1 — GM 12638530 or equivalent

Preparation

1. Park vehicle on level ground and engage parking brake
2. Ensure engine is completely cool to the touch
3. Disconnect negative battery terminal using 10mm socket
4. Remove engine cover by pulling upward on front edge, then lifting off
5. Have a clean workspace ready for valve covers to prevent contamination

Procedure

1. 1

   Remove driver side ignition coils and wiring
   Disconnect the ignition coil electrical connectors on cylinders 1, 3, 5, and 7 (driver side). Remove the ignition coil bolts using 8mm socket and pull each coil straight up from the spark plug tube. Label or arrange coils in order for reinstallation.
   Torque spec

   Ignition Coil Bolts8 Nm (6 lb-ft)
2. 2

   Disconnect driver side valve cover harness and PCV connections
   Disconnect the wire harness from the driver side valve cover. Locate and disconnect the PCV hose from the valve cover. Remove any electrical connector bolts using 10mm socket if harness is bolted to the valve cover. Move harness aside to provide access.
   Torque spec

   Electrical Connector Bolts8 Nm (6 lb-ft)
3. 3

   Remove driver side valve cover
   Remove the 8 valve cover bolts in reverse of the tightening sequence (start from outer bolts, work toward center) using 10mm socket. Carefully lift the valve cover straight up. If stuck, gently tap with a rubber mallet - do not pry against the gasket surface. Remove and discard the old gasket.
   ⚠Do not pry against aluminum gasket surfaces as this will cause damage and future leaks.
   Torque spec

   Cover Bolts20 Nm (15 lb-ft)
4. 4

   Remove passenger side ignition coils and wiring
   Disconnect the ignition coil electrical connectors on cylinders 2, 4, 6, and 8 (passenger side). Remove the ignition coil bolts using 8mm socket and pull each coil straight up from the spark plug tube. Label or arrange coils in order for reinstallation.
   Torque spec

   Ignition Coil Bolts8 Nm (6 lb-ft)
5. 5

   Disconnect passenger side valve cover connections
   Disconnect any wire harness connections from the passenger side valve cover. Remove any electrical connector bolts using 10mm socket. Disconnect the breather hose if equipped. Move all wiring and hoses aside to provide clear access to valve cover bolts.
   Torque spec

   Electrical Connector Bolts8 Nm (6 lb-ft)
6. 6

   Remove passenger side valve cover
   Remove the 8 valve cover bolts in reverse of the tightening sequence using 10mm socket. Carefully lift the valve cover straight up. If stuck, gently tap with a rubber mallet - do not pry against the gasket surface. Remove and discard the old gasket.
   ⚠Do not pry against aluminum gasket surfaces as this will cause damage and future leaks.
   Torque spec

   Cover Bolts20 Nm (15 lb-ft)
7. 7

   Inspect and replace spark plug tube seals
   Inspect all 8 spark plug tube seals in the cylinder head. If any show signs of oil leakage, deterioration, or hardening, remove them using needle nose pliers. Press new spark plug tube seals into place by hand until fully seated - they install by press fit only and require no torque.
   ℹ️Spark plug tube seals are a common source of oil leaks and should be replaced if any doubt exists about their condition.
8. 8

   Clean all gasket mating surfaces
   Using a plastic gasket scraper, carefully remove all old gasket material from both valve cover mating surfaces and cylinder head mating surfaces. Clean surfaces thoroughly with brake cleaner and lint-free rags. Ensure no gasket material or debris falls into the engine. Inspect for any damage to mating surfaces.
   ⚠Never use metal scrapers on aluminum gasket surfaces. Use only plastic tools to prevent surface damage.
   Torque spec

   Gasket Surface Bolts26 Nm (19 lb-ft)
9. 9

   Install new driver side valve cover gasket
   Install the new driver side 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 new grommets are installed in all bolt holes. Verify the gasket is not twisted or pinched anywhere.
10. 10

    Install driver side valve cover
    Carefully position the driver side valve cover onto the cylinder head, ensuring proper alignment with all bolt holes. Install all 8 valve cover bolts finger-tight first. Using a torque wrench, tighten bolts in sequence (center bolts first, then work outward in a criss-cross pattern) to 10 Nm (7 lb-ft). Do not over-torque.
    ⚠Over-torquing valve cover bolts will deform the cover and cause leaks. Use a torque wrench and follow the specified sequence.
    Torque spec

    Cover Bolts20 Nm (15 lb-ft)
11. 11

    Install new passenger side valve cover gasket
    Install the new passenger side 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 new grommets are installed in all bolt holes. Verify the gasket is not twisted or pinched anywhere.
12. 12

    Install passenger side valve cover
    Carefully position the passenger side valve cover onto the cylinder head, ensuring proper alignment with all bolt holes. Install all 8 valve cover bolts finger-tight first. Using a torque wrench, tighten bolts in sequence (center bolts first, then work outward in a criss-cross pattern) to 10 Nm (7 lb-ft). Do not over-torque.
    ⚠Over-torquing valve cover bolts will deform the cover and cause leaks. Use a torque wrench and follow the specified sequence.
    Torque spec

    Cover Bolts20 Nm (15 lb-ft)
13. 13

    Reinstall spark plugs if removed
    If spark plugs were removed during the procedure, apply a small amount of anti-seize compound to the threads. Install spark plugs finger-tight, then torque to 20 Nm (15 lb-ft) using a torque wrench with spark plug socket.
    Torque spec

    Spark Plugs - Aluminum Head20 Nm (15 lb-ft)
14. 14

    Reinstall ignition coils and electrical connections
    Reinstall all 8 ignition coils in their original positions, ensuring they seat fully into the spark plug tubes. Install ignition coil bolts and torque to 8 Nm (6 lb-ft). Reconnect all ignition coil electrical connectors. Reconnect all wire harness connections to both valve covers and torque electrical connector bolts to 8 Nm (6 lb-ft) if applicable.
    Torque spec

    Ignition Coil Bolts8 Nm (6 lb-ft)

    Electrical Connector Bolts8 Nm (6 lb-ft)
15. 15

    Reconnect PCV system and final connections
    Reconnect the PCV hose to the driver side valve cover. Reconnect the breather hose to the passenger side valve cover if equipped. Verify all electrical connections are secure and properly seated. Reinstall the engine cover by aligning the grommets and pressing down firmly. Reconnect the negative battery terminal and torque to 10 Nm using 10mm socket.

Reassembly

1. Ensure all electrical connectors are fully seated and locked
2. Verify PCV and breather hoses are properly connected and secured
3. Double-check that all valve cover bolts were torqued to specification in the proper sequence
4. Confirm engine cover is properly seated on all mounting points

Verification

• Start the engine and listen for any unusual valve train noise or vacuum leaks
• Inspect both valve covers for oil leaks while engine is running
• Allow engine to reach operating temperature and recheck for leaks
• After initial test drive, recheck valve cover area for any signs of oil seepage
• Verify no check engine light or misfire codes are present

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