Engine Oil Cooler

Remove and replace the engine oil cooler assembly, including disconnecting coolant lines, removing the cooler mounting hardware, and installing a new cooler with fresh gaskets.

Warnings

Tools required

Parts

• Engine oil cooler assembly × 1 — Use OEM specification
• Oil cooler gasket set × 1 — Use OEM specification
• Coolant hose clamps × 2 — As needed for replacement
• Oil cooler line O-rings or seals × 2 — Use OEM specification

Fluids

• 10W-30 or 10W-40 conventional engine oil — 5 qt
• Ethylene glycol green 50/50 coolant — 3 qt

Preparation

1. Park vehicle on level ground and apply parking brake
2. Allow engine to cool completely (minimum 2 hours after last operation)
3. Disconnect negative battery cable
4. Place drain pan under engine oil drain plug and drain engine oil completely
5. Place drain pan under radiator and drain approximately 3 quarts of coolant
6. Clean the work area around the oil cooler location on the driver's side of the engine block

Procedure

1. 1

   Locate and access the oil cooler
   Locate the installed oil cooler and identify its type. It may be an air-to-oil cooler mounted in front of the radiator (connected only by engine oil lines, no coolant lines) or a retrofit coolant-to-oil unit. Inspect all connected lines to determine whether coolant is involved before disconnecting anything. Clear any components obstructing access as necessary.
2. 2

   Disconnect coolant supply line
   Using a line wrench to prevent rounding, loosen the coolant inlet line fitting at the oil cooler. The fitting connects the cooler to the cooling system. Once loose, carefully remove the line and allow residual coolant to drain into your catch pan. Cap or plug the line end to prevent contamination.
3. 3

   Disconnect coolant return line
   Similarly, use a line wrench to loosen and disconnect the coolant return line from the oil cooler outlet. Allow coolant to drain completely. Cap or plug this line as well to keep debris out of the cooling system.
4. 4

   Disconnect engine oil lines
   Locate the two oil lines connecting the oil cooler to the engine block. These are typically threaded fittings. Using a line wrench, carefully loosen and remove both oil line fittings from the cooler. Have a drain pan positioned to catch residual oil. Inspect the lines for damage or wear.
5. 5

   Remove oil cooler mounting bolts
   The oil cooler is secured by mounting bolts or brackets specific to the installed unit; count the fasteners present before removal. Using an appropriate socket, remove these bolts and set them aside. Keep track of any spacers or washers that may be present.
6. 6

   Remove oil cooler assembly
   Carefully pull the oil cooler away from the engine block mounting surface. There will be a gasket between the cooler and block that will likely stick. Wiggle the cooler gently if needed to break the gasket seal, then remove the assembly completely. Keep the cooler upright to minimize oil spillage.
7. 7

   Clean mounting surface
   Using a scraper and wire brush, thoroughly clean the oil cooler mounting surface on the engine block. Remove all traces of old gasket material, oil residue, and debris. The surface must be completely clean and smooth for proper sealing. Wipe clean with a shop rag.
8. 8

   Prepare new oil cooler
   Unbox the new oil cooler and verify it matches the original unit in port locations and mounting hole alignment. Install new O-rings or seals on the oil line ports if provided in the gasket kit. Lightly coat the O-rings with clean engine oil to aid installation and prevent tearing.
9. 9

   Install new gasket
   Position the new oil cooler gasket onto the engine block mounting surface. Ensure the gasket is oriented correctly with all holes aligned to the mounting bolt locations and coolant/oil passages. The gasket should sit flat without buckling.
10. 10

    Install new oil cooler
    Carefully position the new oil cooler assembly onto the mounting surface, aligning it with the gasket and mounting bolt holes. Press the cooler gently against the block to seat the gasket. Insert the mounting bolts with any original spacers or washers and hand-tighten them initially.
11. 11

    Torque oil cooler mounting bolts
    Using a torque wrench, tighten the oil cooler mounting bolts in an alternating pattern to ensure even gasket compression. Torque to the aftermarket cooler manufacturer's specification. Do not over-torque as this can distort the cooler body or crack the gasket.
12. 12

    Reconnect engine oil lines
    Thread the engine oil line fittings into the new oil cooler ports by hand first to avoid cross-threading. Once hand-tight, use a line wrench to snug the fittings securely. Typical tightness is snug plus 1/4 to 1/2 turn. Do not over-tighten as this can damage the fittings or cooler ports.
13. 13

    Reconnect coolant lines
    Reconnect both coolant lines to the oil cooler inlet and outlet ports. Thread fittings by hand first, then snug with a line wrench. Ensure all connections are tight to prevent coolant leaks. If hose clamps are used instead of threaded fittings, position new clamps and tighten securely.
14. 14

    Refill engine oil
    Reinstall the engine oil drain plug if removed. If engine oil was drained, reinstall the drain plug and refill the engine with approximately 5 quarts of 10W-30 or 10W-40 conventional engine oil (verify capacity, typically 5 quarts with a new filter) through the oil filler cap. Check the dipstick to verify proper oil level. Check the dipstick to verify proper oil level.
15. 15

    Refill and bleed cooling system
    Refill the radiator with ethylene glycol green 50/50 coolant mixture. Start with approximately 3 quarts to replace what was drained, then top off the radiator as needed. With the radiator cap off, start the engine and allow it to reach operating temperature to bleed air from the cooling system. Add coolant as the level drops. Once the thermostat opens and coolant circulates, top off the radiator and install the cap.

Reassembly

1. Reconnect the negative battery cable
2. Verify all coolant and oil line connections are tight and secure
3. Double-check that no tools or shop rags were left in the engine compartment

Verification

• With the engine running at operating temperature, inspect all oil cooler connections for leaks (both oil and coolant)
• Check engine oil level on dipstick and verify it is at the full mark
• Check coolant level in radiator and overflow tank, top off if needed
• Monitor engine oil pressure gauge or warning light to ensure normal oil pressure
• After the first 50-100 miles of driving, re-inspect all connections for any seepage or leaks
• Verify coolant level again after the first drive cycle and top off if necessary

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