Valve Seals

Replace valve stem seals on the 3.0L V6 Twin Turbo engine to correct oil consumption or smoking issues. This procedure requires removing camshafts and valve train components while maintaining timing alignment.

Warnings

Tools required

Parts

• Valve stem seal set (12 intake, 12 exhaust) × 1 — Use OEM specification
• Valve cover gasket set (left and right) × 2 — Use OEM specification
• Camshaft cover gaskets × 2 — Use OEM specification
• Spark plug tube seals × 6 — Use OEM specification
• Timing cover gasket × 1 — Use OEM specification
• Engine oil × 6 — Selenia Racing 10W-60
• Oil filter × 1 — Use OEM specification
• Spark plugs (if worn) × 6 — NGK or OEM equivalent
• Anti-seize compound × 1 — Use OEM specification

Fluids

• Selenia Racing 10W-60 — 5.5 qt

Preparation

1. Park vehicle on level surface and allow engine to cool completely (minimum 4 hours)
2. Disconnect negative battery cable and isolate from battery terminal
3. Remove engine cover panels and plastic trim pieces from top of engine
4. Drain engine oil completely and remove oil filter
5. Remove air intake system including air filter housing and intake tubes to turbos
6. Disconnect all electrical connectors from valve covers, ignition coils, and cam position sensors
7. Label and photograph all vacuum lines and electrical connections for reinstallation reference
8. Remove ignition coils from all six cylinders
9. Position shop crane or support bar if engine movement is needed for access

Procedure

1. 1

   Remove valve covers
   Remove all bolts securing both valve covers in the reverse of tightening sequence (outside to inside). Carefully lift valve covers off, noting spark plug tube seal locations. If covers are stuck, gently tap with soft mallet at reinforced areas only. Inspect for oil pooling in cylinder head valleys and clean thoroughly.
   Torque spec

   Cover Bolts18 Nm (13 lb-ft)
2. 2

   Remove spark plugs and prepare cylinders
   Remove all six spark plugs using proper spark plug socket. Inspect plugs for oil fouling which confirms seal failure. Clean debris from spark plug wells using compressed air. Thread compressed air adapter into cylinder #1 spark plug hole but do not pressurize yet.
   Torque spec

   Spark Plugs - Aluminum Head20 Nm (15 lb-ft)
3. 3

   Rotate engine to TDC cylinder #1
   Rotate engine clockwise using crankshaft bolt to bring cylinder #1 to top dead center on compression stroke. Verify timing marks on camshaft sprockets align with cylinder head reference marks. Install camshaft alignment tools to lock camshafts in position. This is critical reference position for reassembly.
   ⚠Verify both intake and exhaust cam timing marks are aligned before proceeding. Misalignment indicates incorrect valve timing.
4. 4

   Remove timing chain tensioners and guides
   Remove timing chain tensioner bolts and carefully extract tensioners from both banks. Install timing chain locking tool to prevent chain movement. Remove upper timing chain guides if they obstruct camshaft removal. Keep all hardware organized by cylinder bank.
   Torque spec

   Mounting Bolts50 Nm (37 lb-ft)
5. 5

   Remove camshaft bearing caps
   Mark each camshaft bearing cap with cylinder number and orientation using paint pen. Loosen camshaft cap bolts in reverse sequence (outside to center) in multiple passes, 1/4 turn at a time to prevent camshaft distortion. Remove bolts and caps, keeping them in exact order. Note the locating dowels in some caps.
   ⚠️Loosen cap bolts gradually and evenly. Uneven loosening will bend camshafts causing permanent damage.
   Torque spec

   Camshaft Cap Bolts14 Nm (10 lb-ft)
6. 6

   Remove camshafts and rocker arms
   With all caps removed, carefully lift camshafts straight up from cylinder head. Place camshafts on clean padded surface in order. Remove rocker arms and hydraulic lash adjusters, keeping them organized by cylinder number in numbered compartments or egg carton. Never mix up rocker arms or lash adjusters between cylinders.
   ⚠Rocker arms and lash adjusters are wear-matched to their bores. Mixing components will cause accelerated wear and valve train noise.
7. 7

   Compress valve springs and remove seals - Cylinder 1
   Apply 90-100 PSI compressed air to cylinder #1 through spark plug adapter to hold valves against seats. Install valve spring compressor on intake valve #1. Compress spring carefully until keepers are accessible. Use magnetic pickup to remove both keepers. Slowly release spring tension and remove retainer and spring. Use seal removal tool or needle-nose pliers to carefully extract old valve seal from guide. Repeat for all four valves in cylinder #1 (2 intake, 2 exhaust).
   ⚠️Maintain constant air pressure. If a valve drops into cylinder, camshafts cannot be reinstalled and cylinder head removal will be required.
   ⚠Never pry against valve stem or guide. Damage to these components requires cylinder head replacement.
8. 8

   Install new valve seals - Cylinder 1
   Lubricate new valve seal with clean engine oil. Position seal installation tool over valve guide. Slide new seal onto tool and over guide, ensuring it is not twisted. Press seal firmly onto guide until it bottoms on cylinder head. Seal should sit evenly around guide. Reinstall valve spring, retainer, and keepers using spring compressor. Verify keepers are fully seated in valve stem groove before releasing compressor. Remove air pressure adapter. Repeat process for remaining three valves in cylinder #1.
   ⚠Ensure keepers are properly seated. Improperly installed keepers will cause valve spring to launch during engine operation.
9. 9

   Complete valve seal replacement for remaining cylinders
   Rotate engine to bring each cylinder to TDC in firing order sequence (1-4-2-5-3-6 for this engine). Install air pressure adapter in each cylinder's spark plug hole and repeat valve seal replacement procedure from steps 7-8 for all remaining cylinders. Work methodically and verify each keeper installation before moving to next valve. This will take approximately 3-4 hours for all cylinders.
   ℹ️Work on only one cylinder at a time and verify all four valves are complete before moving to next cylinder.
10. 10

    Reinstall rocker arms and hydraulic lash adjusters
    Return engine to cylinder #1 TDC position. Install hydraulic lash adjusters into their original bores, coating with clean engine oil. Install rocker arms onto valve stems and lash adjusters in original positions. Verify each rocker arm moves freely and is properly seated on valve stem and adjuster.
    ⚠Lash adjusters must be returned to original positions. New positions will cause improper valve clearances.
11. 11

    Reinstall camshafts
    Generously coat camshaft journals and lobes with assembly lube or fresh engine oil. Carefully lower camshafts into position in cylinder head, ensuring they are in original locations (intake vs exhaust). Verify camshaft timing alignment marks are positioned correctly with crankshaft at TDC #1. Install camshaft alignment tools to hold position.
    ⚠️Camshaft timing marks must align exactly with cylinder head reference marks. Incorrect timing will destroy engine on startup.
12. 12

    Install camshaft bearing caps
    Apply thin film of engine oil to bearing cap contact surfaces. Install bearing caps in exact original positions following marked orientation. Install all cap bolts finger tight. Tighten camshaft cap bolts in sequence from center outward in multiple passes: first pass 5 Nm, second pass 10 Nm, final pass 14 Nm. Verify camshafts rotate smoothly by hand after torquing.
    ⚠Follow tightening sequence precisely. Incorrect sequence will bind camshafts or distort bearing bores.
    Torque spec

    Camshaft Cap Bolts14 Nm (10 lb-ft)
13. 13

    Reinstall timing components
    Remove camshaft alignment tools and verify timing marks remain aligned. Remove timing chain locking tool. Reinstall timing chain guides and tensioners. Tighten tensioner mounting bolts to specification. Manually rotate engine two complete revolutions clockwise and verify all timing marks realign perfectly. If marks do not align, disassemble and correct timing before proceeding.
    ⚠️If timing marks do not realign after two revolutions, timing is incorrect. Do not start engine or catastrophic damage will occur.
    Torque spec

    Mounting Bolts50 Nm (37 lb-ft)
14. 14

    Reinstall spark plugs
    Apply small amount of anti-seize compound to spark plug threads (avoid electrode end). Install spark plugs hand-tight, then torque to specification using torque wrench and proper spark plug socket. Do not overtighten as aluminum cylinder head threads are easily damaged.
    ⚠Cross-threading spark plugs in aluminum heads causes expensive cylinder head repair. Thread carefully by hand first.
    Torque spec

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

    Install valve covers and reassemble accessories
    Install new valve cover gaskets and spark plug tube seals in valve covers. Position valve covers carefully to avoid displacing seals. Install valve cover bolts and tighten in sequence from center outward to specification. Reinstall ignition coils, electrical connectors, cam sensors, and intake system. Reconnect all vacuum lines per original routing. Fill engine with correct quantity and specification of oil. Install new oil filter.
    Torque spec

    Cover Bolts18 Nm (13 lb-ft)

    Sensor Bolts11 Nm (8 lb-ft)

    Electrical Connector Bolts7 Nm (5 lb-ft)

Reassembly

1. Double-check all electrical connectors are fully seated and locked
2. Verify all bolts have been reinstalled and torqued to specification
3. Confirm oil drain plug is tight and oil level is correct on dipstick
4. Reconnect negative battery cable
5. Install engine covers and trim pieces

Verification

• Before starting engine, manually rotate crankshaft two full revolutions and verify smooth rotation with no binding or unusual resistance
• Prime oil system by cranking engine with fuel system disabled (pull fuel pump fuse) for 10-15 seconds to build oil pressure
• Start engine and verify oil pressure rises immediately (within 2-3 seconds)
• Listen for any unusual valve train noise, ticking, or tapping that was not present before
• Check for oil leaks around valve covers and timing cover while engine runs
• Allow engine to reach operating temperature and verify no smoke from exhaust (may have light smoke initially from assembly oil burning off)
• After 20 minutes of running, shut down and recheck oil level - top off if needed
• Test drive vehicle and verify normal power delivery and smooth operation through RPM range
• After 100 miles, recheck valve cover bolt torque and oil level
• Monitor oil consumption over next 500-1000 miles to verify seal replacement was successful

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