Engine Oil Cooler

Remove and replace the engine oil cooler assembly on a 1992 Dodge Viper 8.0L V10, including coolant drain, hose disconnection, and mounting bolt removal.

Warnings

Tools required

Parts

• Engine oil cooler assembly × 1 — Mopar 04686307 or equivalent
• Oil cooler mounting gasket/O-ring set × 1 — Use OEM specification
• Coolant hose clamps (if damaged) × 2 — Worm-gear style, appropriate size

Fluids

• Ethylene glycol 50/50 coolant — 3 qt

Preparation

1. Park vehicle on level surface and engage parking brake
2. Allow engine to cool completely (minimum 2 hours after last operation)
3. Disconnect negative battery cable to prevent accidental fan engagement
4. Place drain pans beneath radiator drain and oil cooler area
5. Raise front of vehicle and support on jack stands if additional access is needed from below

Procedure

1. 1

   Drain cooling system
   Open the radiator drain petcock located at the bottom of the radiator and drain coolant into a drain pan sufficient to lower the level below the oil cooler connections (verify system capacity against the 1992 Viper FSM). This will lower the coolant level below the oil cooler connections to minimize spillage. Close the petcock once coolant level drops below the oil cooler mounting location on the engine block.
   Torque spec

   Drain Petcock7 Nm (5 lb-ft)
2. 2

   Access oil cooler assembly
   Locate the engine oil cooler mounted on the driver's side of the engine block, below the cylinder head. The oil cooler is a cylindrical assembly with coolant hoses attached. Remove any plastic engine covers or air intake components that obstruct access to the oil cooler area. On the 1992 Viper, you may need to move aside wiring harnesses or temporarily relocate the power steering reservoir for improved access.
   ℹ️Take photos of hose routing and component positions before disassembly for reference during reassembly.
3. 3

   Disconnect coolant hoses from oil cooler
   Using hose clamp pliers or a flathead screwdriver, loosen the worm-gear clamps on both coolant hoses connected to the oil cooler (inlet and outlet). Slide the clamps back along the hoses away from the cooler connections. Carefully twist and pull the coolant hoses off the oil cooler nipples. Expect residual coolant to drain; use shop towels and drain pan to contain spillage. Inspect hoses for cracks, hardening, or damage and replace if necessary.
   Torque spec

   Hose Clamps3 Nm (2 lb-ft)
4. 4

   Remove oil cooler mounting bolts
   The oil cooler is secured to the engine block with mounting bolts (verify exact count against factory service manual before removal). Using the appropriate metric socket, remove these mounting bolts completely. Support the oil cooler with one hand while removing the final bolt to prevent it from falling. Note the bolt length and any spacers or washers present for proper reassembly.
   ⚠Oil will drain from the cooler passages when removed. Position drain pan to catch approximately 1 quart of engine oil.
   Torque spec

   Mounting Bolts27 Nm (20 lb-ft)
5. 5

   Remove oil cooler assembly
   Carefully pull the oil cooler assembly straight out from the engine block. The cooler connects to internal oil passages through a machined port with O-ring seals. Wiggle gently if resistance is felt, but do not pry against the engine block surface. Once removed, allow oil to drain completely into the drain pan. Keep the cooler upright to minimize oil spillage.
   ℹ️The removed oil cooler will continue to drip oil. Place it in a drain pan or on absorbent material.
6. 6

   Inspect mounting surface and passages
   With the oil cooler removed, inspect the engine block mounting surface for damage, corrosion, or debris. The oil passage port should be clean and free of obstruction. Remove the old gasket or O-ring seals from both the engine block and the old oil cooler using a plastic scraper. Do not use metal tools that could scratch the sealing surfaces. Clean the mounting surface thoroughly with shop towels and brake cleaner or degreaser. Inspect the coolant passage nipples on the engine block (if separate from cooler) for corrosion or damage.
7. 7

   Prepare new oil cooler
   Unpack the new oil cooler assembly and verify it matches the original unit in terms of port locations, mounting bolt pattern, and coolant nipple configuration. Install the new O-ring seals or gaskets onto the oil cooler according to the gasket kit instructions. Lightly lubricate the O-rings with clean engine oil to ease installation and prevent tearing. If the new cooler has separate coolant nipples, install them now with appropriate sealant or gaskets per manufacturer instructions.
8. 8

   Install new oil cooler assembly
   Carefully align the new oil cooler with the engine block mounting port, ensuring the O-rings are properly seated in their grooves. Push the cooler straight into the block until it seats fully against the mounting surface. Do not rotate or rock the cooler during installation as this can damage the O-rings. Insert the mounting bolts by hand and thread them several turns to hold the cooler in position.
   ⚠Cross-threading the mounting bolts into the aluminum block can cause expensive damage. Ensure bolts thread smoothly by hand before using tools.
9. 9

   Torque oil cooler mounting bolts
   Using a torque wrench, tighten the oil cooler mounting bolts to the factory-specified torque (verify against the 1992 Viper FSM) in a criss-cross pattern if multiple bolts, or evenly if two bolts. Do not over-torque as the engine block is aluminum and threads can strip. Verify the cooler is seated flush against the engine block with no gaps around the perimeter.
   Torque spec

   Mounting Bolts27 Nm (20 lb-ft)
10. 10

    Reconnect coolant hoses
    Slide the coolant hoses onto the oil cooler inlet and outlet nipples, pushing them fully onto the barbed fittings. Ensure each hose is seated past the barb ridge. Slide the hose clamps into position over the hose-to-nipple connection area (approximately 1/2 inch from the end of each nipple). Tighten the worm-gear clamps to 3 Nm (2 lb-ft), which is snug but not over-tightened. Over-tightening can cut into the hose material.
    Torque spec

    Hose Clamps3 Nm (2 lb-ft)
11. 11

    Refill cooling system
    Close the radiator drain petcock hand tight; do not apply a torque wrench as over-tightening can damage the petcock. Remove the radiator cap or coolant reservoir cap (depending on fill point on this vehicle). Pour the specified ethylene glycol 50/50 coolant mixture into the system slowly to allow air to escape. Fill to the appropriate level mark. On the 1992 Viper, you may need to open coolant bleeder valves if equipped to purge air from the system. Consult the cooling system service procedure for complete bleeding instructions if air pockets persist.
    ℹ️The cooling system may require bleeding after refill to remove air pockets. Failure to bleed properly can cause overheating.
    Torque spec

    Drain Petcock7 Nm (5 lb-ft)
12. 12

    Check engine oil level
    After oil cooler installation, approximately 1 quart of engine oil was lost during removal. Check the engine oil level using the dipstick and add oil as necessary to bring the level to the full mark. Use the manufacturer-specified oil viscosity for the 1992 Viper 8.0L V10 (verify against owner's manual, typically 10W-40). Do not overfill.
13. 13

    Reinstall removed components
    Reinstall any engine covers, air intake components, or other parts that were removed for access. Reconnect the negative battery cable. Double-check that all tools have been removed from the engine bay and all fasteners have been tightened.

Reassembly

1. Ensure all coolant hose clamps are positioned correctly and tightened to specification
2. Verify oil cooler mounting bolts are torqued properly to prevent oil or coolant leaks
3. Confirm engine oil level is correct after accounting for oil loss during cooler removal
4. All components removed for access must be reinstalled securely

Verification

• Start the engine and allow it to reach normal operating temperature while monitoring for leaks around the oil cooler mounting area and coolant hose connections
• Check for oil seepage around the cooler mounting surface, particularly where it mates to the engine block
• Verify coolant level remains stable after warm-up cycle; top off if necessary after system fully purges air
• Inspect for any signs of oil in coolant or coolant in oil, which would indicate a failed internal seal in the new cooler
• Monitor engine oil pressure gauge (if equipped) to ensure normal operating pressure is maintained
• After test drive, recheck all connections for leaks and verify engine oil and coolant levels are correct

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