This procedure covers the replacement of a single freeze plug (core plug) on the 3.6L V6 Pentastar engine, typically requiring access from underneath or removal of nearby components depending on which plug has failed.

Warnings

Tools required

Parts

• Engine freeze plug (size specific to location) × 1 — Use OEM specification - verify size before ordering
• Engine coolant × 1 — Mopar OAT Purple

Fluids

• Mopar OAT Coolant (Purple) — 13 qt

Preparation

1. Verify engine is completely cold to the touch
2. Park vehicle on level ground and engage parking brake
3. Disconnect negative battery terminal
4. Locate the failed freeze plug and determine access requirements
5. Take photos of component locations before disassembly for reference
6. Raise and secure vehicle on jack stands if accessing from underneath
7. Remove engine splash shield if equipped

Procedure

1. 1

   Drain cooling system
   Place drain pan under radiator petcock. Open radiator drain valve at bottom of radiator and allow coolant to drain completely. If freeze plug is located low on engine block, also open engine block drain plugs if accessible to ensure complete drainage below the work area.
2. 2

   Remove obstructing components
   Based on freeze plug location, remove components blocking access. Common obstructions include: starter motor (if driver side front), exhaust heat shields, motor mount brackets, AC compressor mounting bolts (support without disconnecting lines), or power steering reservoir. Document all fastener locations and save hardware in labeled containers.
   ⚠Do not disconnect AC lines unless system has been properly evacuated by certified technician. Support components with wire or bungee cords.
   Torque spec

   Mounting Bolts54 Nm (40 lb-ft)
3. 3

   Clean work area around freeze plug
   Use wire brush to clean accumulated dirt, oil, and corrosion from around the failed freeze plug. Clean area must extend at least 2 inches around the plug perimeter. Wipe clean with shop towels to ensure clear visibility and prevent contamination during installation.
4. 4

   Remove failed freeze plug
   Using freeze plug removal tool or large flat screwdriver, punch a hole in the center of the old freeze plug or create an indent near the edge. Pry plug inward to tilt it, then extract using pliers or the removal tool. Work carefully to avoid damaging the bore in the engine block. If plug is severely corroded, it may break into pieces during removal - ensure all fragments are extracted.
   ⚠Do not use excessive force that could damage or enlarge the freeze plug bore in the block. A damaged bore may require oversized plugs or machine shop repair.
5. 5

   Inspect and prepare freeze plug bore
   Thoroughly inspect the freeze plug bore for cracks, corrosion, or damage. Use emery cloth or 320-grit sandpaper to clean the bore surface until bright metal is visible. The bore must be smooth, clean, and free of rust, scale, or old sealant. Wipe bore clean with a lint-free cloth dampened with brake cleaner. Measure bore diameter if there is any question about correct replacement plug size.
   ℹ️Any cracks radiating from the freeze plug bore indicate serious engine block damage requiring professional evaluation.
6. 6

   Prepare new freeze plug
   Verify new freeze plug fits the bore correctly by test-fitting without sealant - it should sit flush at the bore entrance with light hand pressure. Apply a thin, even coat of high-temp RTV silicone sealant around the outer perimeter of the freeze plug, covering the curved edge that will contact the bore.
7. 7

   Install new freeze plug
   Position freeze plug squarely in the bore opening with the concave side facing outward. Using freeze plug installation tool or appropriately sized socket and extension as a driver, tap the plug evenly into the bore. Drive the plug in until the outer edge is approximately 1-2mm below the engine block surface or flush with surrounding plugs. Ensure plug is seated evenly around entire perimeter - check with inspection mirror if needed.
   ⚠Drive plug straight into bore to prevent cocking or binding. An improperly seated plug will leak. Do not over-drive the plug deep into the bore.
8. 8

   Allow sealant to cure and reinstall components
   Allow RTV sealant to set per manufacturer instructions (typically 15-30 minutes minimum). Reinstall all removed components in reverse order of removal. Install new gaskets where required. Clean all gasket surfaces with gasket scraper and brake cleaner before installing new gaskets.
   ℹ️Clean mating surfaces thoroughly before reinstalling components with gaskets to prevent leaks.
   Torque spec

   Mounting Bolts54 Nm (40 lb-ft)

   Gasket Bolts23 Nm (17 lb-ft)

   Gasket Surface Bolts23 Nm (17 lb-ft)
9. 9

   Refill cooling system
   Close radiator petcock and reinstall any engine block drain plugs removed earlier. Fill cooling system with Mopar OAT Purple coolant through radiator or coolant reservoir as appropriate. Use 50/50 premix or mix concentrate to 50/50 ratio with distilled water. Fill until coolant reaches cold fill line on reservoir. Leave radiator cap off if accessible.
10. 10

    Bleed cooling system
    Reconnect negative battery terminal. Start engine and allow to warm to operating temperature with heater on maximum heat. Monitor coolant level and add as needed while engine warms. Watch temperature gauge to ensure normal operation. Once cooling fan cycles on and off, engine is fully warmed. Rev engine to 2500 RPM several times to help purge air pockets. Shut off engine and allow to cool.
    ⚠️Stay clear of cooling fan and moving belts while engine is running. Monitor for coolant leaks from new freeze plug.
11. 11

    Final coolant level adjustment
    Once engine has cooled completely, recheck coolant level in reservoir and radiator. Top off to cold fill line as needed. Install radiator cap. Inspect freeze plug installation area and all reinstalled components for any signs of coolant leakage. Wipe area dry and monitor during verification test.

Reassembly

1. Torque all mounting bolts to specification in the sequence they were removed
2. Replace any gaskets that were disturbed during component removal
3. Ensure all electrical connectors are fully seated and secured
4. Reinstall engine splash shield if removed
5. Lower vehicle from jack stands safely

Verification

• Start engine and allow to reach full operating temperature while monitoring for leaks at freeze plug location
• Check that temperature gauge reads normal and cooling fan cycles properly
• Inspect freeze plug area with flashlight and mirror for any signs of coolant seepage after warm-up cycle
• Test drive vehicle for 10-15 minutes, then recheck coolant level and inspect for leaks with engine hot
• After vehicle cools overnight, verify coolant level is at cold fill line and check freeze plug area is dry
• Monitor coolant level over next several days to confirm no slow leaks are present

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