Complete valve job for 6.7L Cummins diesel including valve cover removal, cylinder head removal, valve grinding/replacement, seat machining, reassembly with new seals and gaskets, and timing system service.

Warnings

Tools required

Parts

• Cylinder head gasket set × 1 — Use OEM Mopar gasket kit
• Valve cover gasket × 1 — Use OEM specification
• Timing cover gasket × 1 — Use OEM specification
• Valve stem seals (set of 24) × 1 — Use OEM specification
• Cylinder head bolts (TTY) × 1 — Use OEM - do not reuse
• Intake manifold gasket × 1 — Use OEM specification
• Exhaust manifold gaskets × 1 — Use OEM specification
• Valve set (intake and exhaust) × 1 — Use OEM - if replacement needed
• Anti-seize compound × 1 — High-temperature rated
• Engine assembly lube × 1 — Mopar or equivalent
• RTV silicone sealant × 1 — Mopar or OEM equivalent

Fluids

• Mopar OAT Coolant (Purple) — 18 qt
• Mopar 5W-20 Synthetic Blend — 13 qt

Preparation

1. Disconnect both battery cables, negative first, and secure away from terminals
2. Drain engine coolant completely into appropriate container using radiator petcock and lower hose
3. Drain engine oil and replace filter
4. Remove engine cover and air intake system including turbocharger inlet piping
5. Label and disconnect all electrical connectors from injectors, sensors, and harnesses on cylinder head
6. Remove intercooler tubes and charge air cooler piping as necessary for access
7. Support engine from above using engine hoist or support fixture if removing mounts
8. Prepare clean workspace with adequate lighting for cylinder head disassembly and inspection

Procedure

1. 1

   Remove valve cover and rocker assembly
   Disconnect breather hoses and wiring from valve cover. Remove valve cover bolts and carefully lift valve cover away. Remove rocker arm assembly by loosening rocker arm bolts evenly in reverse sequence (outboard to center). Note position of each rocker arm and pedestal for reassembly. Remove pushrods and keep in order.
   Torque spec

   Cover Bolts22 Nm (16 lb-ft)

   Rocker Arm Bolts30 Nm (22 lb-ft)
2. 2

   Remove intake and exhaust manifolds
   Disconnect EGR valve and all intake manifold connections. Remove intake manifold bolts and lift manifold away. Disconnect exhaust manifold from turbocharger and remove exhaust manifold nuts working from hot side (center) toward cold ends. Remove exhaust manifold and inspect studs for damage.
   ⚠Exhaust manifold studs are prone to breaking. Apply penetrating oil 24 hours before removal if possible.
   Torque spec

   Intake Manifold Bolts25 Nm (18 lb-ft)

   Exhaust Manifold Nuts30 Nm (22 lb-ft)
3. 3

   Remove timing cover and set timing position
   Remove accessory drive belts and crankshaft damper. Remove timing cover bolts in reverse sequence and carefully pry timing cover away using plastic pry tools. Rotate engine to bring cylinder 1 to TDC compression stroke. Install timing pins to lock crankshaft and camshaft in position before proceeding.
   ⚠️Do not rotate engine after installing timing pins. Engine must remain locked in position to prevent valve timing errors.
   Torque spec

   Cover Bolts22 Nm (16 lb-ft)
4. 4

   Remove timing components
   Mark timing chain direction of rotation. Remove timing chain tensioner bolt and extract tensioner. Remove camshaft sprocket bolt while holding camshaft with wrench on hex section. Remove camshaft sprocket and timing chain as assembly. Support timing chain to prevent dropping into engine.
   Torque spec

   Timing Chain Tensioner Bolt25 Nm (18 lb-ft)

   Camshaft Sprocket Bolt80 Nm (59 lb-ft)
5. 5

   Remove camshaft and cylinder head
   Remove camshaft bearing cap bolts in reverse sequence (outward from center). Carefully lift camshaft from head and protect bearing surfaces. Remove cylinder head bolts in reverse tightening sequence (outside to inside spiral pattern). Use hoist or assistance to lift cylinder head from block. Place head on padded work surface or head stand.
   ⚠Head weighs approximately 200 lbs. Use proper lifting equipment and at least one assistant.
   Torque spec

   Camshaft Cap Bolts14 Nm (10 lb-ft)

   Cylinder Head Bolts65 Nm (48 lb-ft)
6. 6

   Disassemble valvetrain from cylinder head
   Using valve spring compressor, compress each valve spring and remove valve locks (keepers). Release spring tension and remove retainer and springs. Keep all components organized by cylinder and position. Remove valve stem seals. Extract valves and mark each valve with corresponding cylinder number and intake/exhaust position. Inspect all components for wear, burning, or damage.
   ⚠Valve springs are under significant tension. Ensure spring compressor is properly seated before removing locks.
7. 7

   Clean and inspect cylinder head
   Thoroughly clean all carbon deposits from combustion chambers, valve ports, and head gasket surface using appropriate tools. Do not scratch or gouge aluminum surfaces. Inspect head for cracks using dye penetrant or magnetic particle testing. Check head deck surface for warpage using precision straightedge and feeler gauges (maximum 0.002 inch per 6 inches). Measure valve guides for wear using inside micrometer or dial bore gauge.
   ℹ️If head warpage exceeds specification or cracks are found, head must be machined or replaced. Maximum material removal from deck is typically 0.010 inch.
8. 8

   Service valves and seats
   Measure valve stem diameter at multiple points. Check valve margin thickness (minimum 0.030 inch typically). Clean valve faces and stems thoroughly. Grind or replace valves as needed. Machine valve seats to proper angles (typically 30° intake, 45° exhaust with narrowing cuts). Lap valves to seats using lapping compound or verify seat contact with Prussian blue. Clean all lapping compound completely after finishing.
   ℹ️Valve seat contact pattern should be centered on valve face with width of 1.5-2.0mm. Too narrow indicates insufficient sealing.
9. 9

   Install valves with new seals
   Lubricate valve stems with engine assembly lube. Install new valve stem seals using appropriate driver tool - do not hammer directly on seals. Insert valves into guides ensuring correct cylinder and position. Install valve springs with closer-wound coils toward head. Compress springs and install valve locks, ensuring they seat properly in valve stem grooves. Tap valve stem lightly with plastic hammer to verify lock seating.
   ⚠Valve stem seals must be installed to correct depth. Over-installation will cause oil consumption, under-installation causes seal failure.
10. 10

    Prepare block and install cylinder head
    Clean cylinder head mating surface on block thoroughly, removing all old gasket material. Verify block deck surface is clean and free of debris. Check block for warpage. Install new head gasket with locating dowels - do not use any sealant on MLS gasket. Carefully lower cylinder head onto block using hoist, aligning with dowel pins. Install new TTY head bolts finger tight in spiral pattern from center outward.
    ⚠️Use only new TTY cylinder head bolts. Reusing old bolts will result in head gasket failure and potential engine damage.
    Torque spec

    Cylinder Head Bolts65 Nm (48 lb-ft)
11. 11

    Torque cylinder head bolts
    Torque cylinder head bolts in three stages following proper sequence (center outward spiral): Stage 1 - torque all bolts to 65 Nm (48 lb-ft). Stage 2 - tighten all bolts an additional 90 degrees using angle gauge. Stage 3 - tighten all bolts a final 90 degrees. Verify all bolts have been properly torqued and angled.
    ⚠Follow exact torque sequence and angle specifications. Improper tightening will cause head gasket failure.
    Torque spec

    Cylinder Head Bolts65 Nm (48 lb-ft)
12. 12

    Install camshaft and timing components
    Lubricate camshaft lobes and bearing journals with engine assembly lube. Install camshaft into head ensuring bearing alignment. Install camshaft bearing caps in correct positions with arrows pointing toward timing chain end. Torque cap bolts in sequence from center outward in multiple passes to final specification. Install timing chain and camshaft sprocket ensuring proper timing mark alignment. Hold camshaft hex and torque sprocket bolt to specification. Install timing chain tensioner with compression pin installed, then remove pin after bolt is torqued.
    ⚠️Verify timing marks are properly aligned before removing timing pins. Incorrect timing will cause severe engine damage.
    Torque spec

    Camshaft Cap Bolts14 Nm (10 lb-ft)

    Camshaft Sprocket Bolt80 Nm (59 lb-ft)

    Timing Chain Tensioner Bolt25 Nm (18 lb-ft)
13. 13

    Install pushrods and rocker assembly
    Install pushrods in original positions, ensuring they seat properly in lifter sockets. Apply engine assembly lube to rocker arm tips and pedestal bolts. Position rocker arm assembly on head. Rotate engine to position each cam lobe away from its rocker (base circle) before tightening corresponding rocker bolt. Torque rocker arm bolts to specification in sequence from center outward.
    ⚠Each rocker arm bolt must be tightened only when corresponding cam lobe is on base circle (lobe pointing away from rocker). Failure to follow will bend pushrods.
    Torque spec

    Rocker Arm Bolts30 Nm (22 lb-ft)
14. 14

    Install timing cover and valve cover
    Apply thin bead of RTV sealant to timing cover mating surface at block/head junction points. Install new timing cover gasket and position cover on engine. Install timing cover bolts and torque in proper sequence. Clean valve cover mating surface and install new valve cover gasket. Position valve cover and install bolts, torquing in sequence from center outward.
    Torque spec

    Cover Bolts22 Nm (16 lb-ft)
15. 15

    Install manifolds and complete reassembly
    Apply anti-seize compound to exhaust manifold studs. Install exhaust manifold with new gaskets and torque nuts from hot side (center) to cold ends. Install intake manifold with new gaskets and torque bolts in sequence. Reconnect all electrical connections, hoses, and fuel lines. Install all remaining components in reverse order of removal. Refill cooling system with proper coolant mixture. Fill engine with correct oil quantity.
    ℹ️Use only high-temperature anti-seize on exhaust manifold studs to prevent future seizure.
    Torque spec

    Exhaust Manifold Nuts30 Nm (22 lb-ft)

    Intake Manifold Bolts25 Nm (18 lb-ft)

Reassembly

1. Ensure all electrical connectors are fully seated and locked
2. Verify all coolant hoses are properly clamped and routed
3. Double-check that all tools and rags have been removed from engine bay
4. Reconnect battery cables, positive first then negative
5. Burp cooling system to remove air pockets after initial fill

Verification

• Perform static valve lash check to verify proper rocker arm installation and pushrod length
• Check for coolant leaks around head gasket and timing cover before starting engine
• Prime oil system by cranking engine with fuel system disabled until oil pressure registers
• Start engine and verify no abnormal noises, checking for oil and coolant leaks
• Allow engine to reach operating temperature while monitoring for leaks and proper operation
• Perform final coolant system bleed and top off as needed
• Road test vehicle under light load, then recheck all torque specifications after engine has cooled
• Monitor for oil consumption and coolant loss over first 500 miles to verify valve seal installation

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