Complete replacement of all engine block freeze plugs on the 6.7L Cummins diesel engine, requiring engine removal or significant disassembly to access all plugs.

Warnings

Tools required

Parts

• Freeze plug set (complete engine block set) × 1 — Use OEM specification
• Engine coolant × 1 — Mopar OAT Purple
• Engine oil and filter × 1 — Use OEM specification
• Transmission cooler line O-rings × 1 — Use OEM specification
• Engine mount bolts × 4 — Use OEM specification
• High temperature sealant × 1 — Permatex Ultra Black or equivalent
• Valve cover gasket × 1 — Use OEM specification
• Exhaust manifold gaskets × 1 — Use OEM specification

Fluids

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

Preparation

1. Park vehicle on level surface and engage parking brake
2. Disconnect both battery cables, negative first, and secure away from terminals
3. Drain engine coolant completely into appropriate container and dispose properly
4. Drain engine oil and remove oil filter
5. Remove engine cover and air intake system
6. Relieve fuel system pressure at fuel rail Schrader valve
7. Document all electrical connector locations with photos for reassembly reference
8. Support vehicle on jack stands at frame rails with wheels removed for clearance

Procedure

1. 1

   Remove hood and disconnect engine accessories
   Mark hood hinge locations with paint pen for alignment reference. Unbolt and remove hood with assistance. Disconnect all engine wiring harnesses including ECM connectors, injector harnesses, alternator, and all sensors. Label each connection. Disconnect fuel supply and return lines at fuel filter housing. Disconnect coolant hoses at radiator and heater core connections.
2. 2

   Remove radiator and cooling system components
   Disconnect transmission cooler lines at radiator. Remove upper radiator support brackets. Remove radiator fan shroud assembly and radiator as a unit. Remove A/C condenser and secure to front of vehicle without disconnecting refrigerant lines. Disconnect upper and lower radiator hoses and heater hoses at engine block.
3. 3

   Disconnect exhaust and turbocharger components
   Remove exhaust downpipe from turbocharger outlet. Disconnect EGR cooler lines if equipped. Remove turbocharger oil drain tube and coolant lines. It is not necessary to remove turbocharger but secure it to prevent damage during engine removal.
4. 4

   Disconnect transmission from engine
   Support transmission with transmission jack. Remove bellhousing to engine block bolts. Mark torque converter to flexplate orientation. Remove torque converter to flexplate bolts through starter opening. Disconnect all transmission electrical connections. Carefully separate transmission from engine block, ensuring torque converter remains with transmission.
   ⚠Transmission weighs approximately 230 lbs. Ensure jack is properly positioned and rated for weight.
   Torque spec

   Mounting Bolts64 Nm (47 lb-ft)
5. 5

   Remove engine mount bolts and prepare for lift
   Attach engine hoist to factory lifting eyes on cylinder head. Apply slight upward tension to relieve weight from mounts. Remove left and right engine mount through-bolts. Disconnect any remaining wiring, vacuum lines, or hoses attached to engine. Verify engine is completely free from vehicle.
   ⚠️Ensure hoist is rated for minimum 2,000 lb capacity and chains are properly secured to lifting eyes.
   Torque spec

   Mounting Bolts64 Nm (47 lb-ft)
6. 6

   Remove engine from vehicle
   Slowly lift engine while guiding clear of frame rails and body components. Have assistant guide engine to prevent contact with A/C lines, wiring, or body panels. Once clear of engine bay, lower engine onto suitable engine stand rated for diesel engine weight. Secure engine to stand using bellhousing bolt holes.
7. 7

   Remove valve cover and external components
   Remove valve cover bolts and carefully remove valve cover. Remove any remaining accessories blocking access to engine block sides including fuel filter housing, oil filter housing, and starter motor. Clean work area around engine block thoroughly.
   Torque spec

   Cover Bolts22 Nm (16 lb-ft)

   Gasket Bolts27 Nm (20 lb-ft)
8. 8

   Locate and mark all freeze plug positions
   Identify all freeze plug locations on the 6.7L Cummins block. There are typically 8-10 freeze plugs located on both sides of the block and rear of block. Clean area around each freeze plug with wire brush. Inspect each plug for corrosion or leakage to identify problem areas.
9. 9

   Remove old freeze plugs
   Using freeze plug removal tool or punch and hammer, create a dimple in center of freeze plug without puncturing through completely. Use appropriate sized punch to drive plug at an angle, causing it to rotate sideways in bore for removal. Alternatively, drill small hole in center and use slide hammer with screw attachment. Remove all old freeze plugs. Do not damage freeze plug bore surfaces in block.
   ⚠Be careful not to drive punch completely through plug into coolant passages or damage block casting.
10. 10

    Prepare freeze plug bores
    Thoroughly clean each freeze plug bore with wire brush and solvent to remove all corrosion, old sealant, and debris. Inspect bore for cracks or damage. Bores must be clean, dry, and smooth for proper plug seating. Wipe bores with lint-free cloth and allow to dry completely.
11. 11

    Install new freeze plugs
    Apply thin, even bead of high-temperature sealant around outer edge of each new freeze plug as specified. Position freeze plug squarely in bore with convex side facing outward. Using appropriately sized freeze plug installation tool or large socket matching plug diameter, drive plug into bore evenly. Plug should seat flush or slightly below block surface (0.5-1.0mm). Install all freeze plugs and allow sealant to cure per manufacturer specifications.
    ℹ️Some freeze plugs on 6.7L Cummins are threaded cup-style and require torque specification. Apply sealant to threads and torque to specification.
    Torque spec

    Freeze Plug10 Nm (7 lb-ft)
12. 12

    Reinstall engine external components
    Install new valve cover gasket and reinstall valve cover with cover bolts torqued to specification. Reinstall starter motor, fuel filter housing, oil filter housing, and all other components removed for access. Install new oil filter and ensure all sensor connections are clean and ready for installation.
    Torque spec

    Cover Bolts22 Nm (16 lb-ft)

    Sensor Bolts15 Nm (11 lb-ft)
13. 13

    Reinstall engine into vehicle
    Attach engine hoist to lifting eyes and remove engine from stand. Carefully guide engine into engine bay, ensuring proper alignment with engine mounts and transmission. Align engine with transmission bellhousing and carefully slide together, ensuring torque converter pilot engages properly. Install bellhousing to engine mounting bolts finger tight initially.
14. 14

    Install engine mounts and torque all fasteners
    Install engine mount through-bolts and torque mounting bolts to specification. Torque transmission bellhousing bolts to specification in cross pattern. Torque torque converter to flexplate bolts to specification through starter opening. Remove engine hoist once engine is fully secured.
    Torque spec

    Mounting Bolts64 Nm (47 lb-ft)
15. 15

    Reconnect all systems and refill fluids
    Reconnect all wiring harnesses, fuel lines, coolant hoses, and vacuum lines using documentation from disassembly. Install exhaust downpipe to turbocharger. Reinstall radiator, A/C condenser, and fan shroud assembly. Connect transmission cooler lines with new O-rings. Reinstall air intake system and engine cover. Fill engine with specified 13 quarts of Mopar 5W-20 oil. Fill cooling system with 18 quarts of Mopar OAT Purple coolant through overflow tank. Reconnect battery cables, positive first.
    Torque spec

    Gasket Bolts27 Nm (20 lb-ft)

Reassembly

1. Reinstall hood using alignment marks made during removal
2. Bleed cooling system by running engine to operating temperature with heater on high, adding coolant as level drops
3. Check for coolant leaks at all freeze plug locations with engine at operating temperature
4. Verify all electrical connections are secure and all warning lights function normally
5. Reinstall wheels and torque lug nuts to specification

Verification

• Start engine and verify no coolant leaks from any freeze plug locations
• Allow engine to reach full operating temperature and verify cooling system pressure holds
• Check for oil leaks around valve cover and all reinstalled components
• Verify all gauges read normally including coolant temperature and oil pressure
• Test drive vehicle and monitor for any abnormal noises, leaks, or warning lights
• Recheck coolant level after first heat cycle and top off as necessary
• Inspect freeze plug areas after 24 hours and 100 miles for any signs of seepage

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