Engine Oil Cooler

This procedure covers removal and replacement of the engine oil cooler assembly on the 2018-2024 Honda Accord 1.5L turbocharged engine, including coolant draining, oil cooler housing removal, and system refilling.

Warnings

Tools required

Parts

• Engine oil cooler assembly × 1 — Use OEM specification
• Oil cooler O-rings × 2 — Usually included with cooler assembly
• Coolant drain plug washer × 1 — 94109-14000 or equivalent

Fluids

• Honda Type 2 Coolant (Blue) — 2 qt
• Honda Genuine 0W-20 — 0.5 qt

Preparation

1. Ensure engine is completely cool to touch (minimum 2 hours after last operation)
2. Position vehicle on level surface and engage parking brake
3. Open hood and disconnect negative battery terminal
4. Remove engine cover by pulling up on front clips and sliding forward
5. Place drain pan under radiator drain plug location on lower right side of radiator
6. Remove front skid plate or under cover if equipped (10mm bolts)

Procedure

1. 1

   Drain engine coolant
   Locate the coolant drain plug on the lower right side of the radiator. Using a 14mm socket, carefully loosen the drain plug and allow coolant to drain into the pan. Once drained, remove the old washer from the drain plug and set aside. Keep the drained coolant in a sealed container if it will be reused (if clean and less than 5 years old).
   Torque spec

   Coolant Drain Plug15 Nm (11 lb-ft)
2. 2

   Remove radiator cap and relieve system pressure
   With the system drained, slowly remove the radiator cap to ensure all pressure is relieved. This will help remaining coolant drain from upper passages when the oil cooler is removed.
3. 3

   Access the oil cooler assembly
   The oil cooler is located on the front of the engine block, below the oil filter housing. Remove the engine cover completely if not already done. Identify the oil cooler housing - it has coolant hoses connected to the top and is mounted with two bolts to the engine block. Place towels around the work area to catch residual oil and coolant.
4. 4

   Disconnect coolant hoses from oil cooler
   Using hose clamp pliers or a flathead screwdriver, loosen the hose clamps on both coolant hoses connected to the top of the oil cooler assembly. Slide the clamps back away from the connection points. Gently twist and pull the hoses off the cooler ports. Additional coolant will drain - have a drain pan positioned to catch it. Plug the hoses with clean shop towels to prevent debris entry.
   ⚠Coolant hoses may be stiff from heat cycling. Do not use excessive force to avoid damaging the ports.
   Torque spec

   Hose Clamps3 Nm (2 lb-ft)
5. 5

   Remove oil cooler mounting bolts
   Locate the two oil cooler mounting bolts securing the assembly to the engine block. Using a 12mm socket and ratchet, remove both mounting bolts completely. Keep these bolts as they will be reused. The cooler assembly is now free to be removed but will still have oil residue.
   Torque spec

   Mounting Bolts26 Nm (19 lb-ft)
6. 6

   Remove oil cooler assembly
   Carefully pull the oil cooler assembly straight out from the engine block. There will be two O-rings that seal the cooler to the block oil passages. Expect residual engine oil to drain from both the cooler and the block passages. Allow to fully drain into your pan. Inspect the removed cooler for cracks, leaks, or damage to determine if replacement is necessary.
   ℹ️Approximately 0.25-0.5 quarts of engine oil will drain from the cooler passages.
7. 7

   Clean mounting surface and inspect block
   Using a clean shop towel, thoroughly clean the oil cooler mounting surface on the engine block. Remove any old O-ring material using a pick - be careful not to scratch or gouge the aluminum block surface. Inspect the oil passage openings for debris or damage. Clean any oil residue from the surrounding area.
   ⚠Do not allow any debris or dirt to enter the exposed oil passages. Cover with clean towels if taking a break.
8. 8

   Prepare new oil cooler assembly
   Unpack the new oil cooler assembly and verify it matches the original. Install new O-rings into the grooves on the oil cooler (there should be two O-rings - one for each oil passage port). Lightly coat the O-rings with clean engine oil to aid installation and prevent pinching. Ensure O-rings are properly seated in their grooves.
9. 9

   Install new oil cooler assembly
   Carefully align the new oil cooler with the mounting holes and oil passages on the engine block. Push the cooler straight into the block, ensuring the O-rings seat properly. The cooler should sit flush against the block surface. Start both mounting bolts by hand to ensure proper thread engagement before tightening.
10. 10

    Torque oil cooler mounting bolts
    Using a torque wrench and 12mm socket, tighten both oil cooler mounting bolts to specification. Tighten in an alternating pattern to ensure even seating of the cooler assembly against the block.
    Torque spec

    Mounting Bolts26 Nm (19 lb-ft)
11. 11

    Reconnect coolant hoses
    Remove the shop towel plugs from the coolant hoses. Clean the inside of the hose ends if any debris is present. Slide the hoses onto the oil cooler ports, ensuring they are fully seated. Position the hose clamps over the connection points and tighten to specification using hose clamp pliers or a socket.
    Torque spec

    Hose Clamps3 Nm (2 lb-ft)
12. 12

    Reinstall coolant drain plug
    Install the new drain plug washer onto the drain plug. Thread the drain plug into the radiator by hand, then tighten to specification using a 14mm socket and torque wrench.
    Torque spec

    Coolant Drain Plug15 Nm (11 lb-ft)
13. 13

    Refill cooling system
    Using a coolant funnel with radiator adapter, slowly refill the cooling system with Honda Type 2 (blue) coolant. Fill the radiator to the top, then fill the coolant reservoir to the MAX line. Start the engine and allow it to reach operating temperature with the radiator cap off. Add coolant as the level drops during burping. Watch for leaks around the oil cooler connections.
    ⚠Monitor coolant temperature during burping process. Do not allow engine to overheat.
14. 14

    Check and adjust engine oil level
    With the engine off, check the engine oil level on the dipstick. The oil cooler removal process will have drained some oil from the system. Add Honda Genuine 0W-20 oil as needed to bring the level to the upper mark on the dipstick. Do not overfill.

Reassembly

1. Reinstall engine cover by sliding rear tabs into slots and pressing down front clips until they click
2. Reinstall front skid plate or under cover if removed
3. Reconnect negative battery terminal
4. Properly dispose of drained coolant and oil according to local regulations

Verification

• Start engine and allow to reach full operating temperature while monitoring for leaks around oil cooler assembly
• Check for coolant leaks at both hose connections and around the cooler mounting surface
• Verify coolant level in reservoir is at MAX line after engine reaches operating temperature
• Check engine oil level again after test drive and verify no oil leaks from cooler mounting area
• Monitor engine temperature gauge during test drive to ensure proper cooling system operation
• Recheck all connections and fluid levels after 24 hours of normal driving

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