Oil Cooler Seal Replacement

Overview

This procedure replaces the oil cooler seals on a Porsche 944 S / S2 with a 16v engine. The oil cooler seals prevent oil and coolant from mixing. If they fail, you might notice a “milkshake” mixture in the coolant tank, which requires immediate replacement to avoid engine damage. This guide focuses on the S / S2 variant, ensuring a clean coolant system and preventing coolant from contaminating the oil.

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Tools Required

• Metric socket set
• Metric combination wrench set
• Thin head 24mm (15/16 inch) open end wrench
• Alignment Tool 9262/1 (for oil pressure relief valve 944 107 035 02)
• 10mm (3/8 inch) socket and ratchet or 10mm (3/8 inch) combination wrench
• 13mm (1/2 inch) socket and ratchet or 13mm (1/2 inch) combination wrench

Parts Required

• Integral gasket 944 107 147 03 (1)
• O-ring 999 707 043 40 (2)
• Plastic washer 944 107 154 00 (1)
• Rubber seal 944 107 153 02 (1)
• Shim 944 107 219 00 (as needed, 0.5 mm thickness)

Required Additional Procedures

Steps in these procedures are required to complete this process:

• Coolant System Draining, Filling, and Venting
• Oil Pressure Relief Valve

Step-by-Step Procedure

1. Prepare the Vehicle

1. Lift the Porsche 944 S / S2 onto jack stands securely.
2. Remove the belly pan to access the oil cooler area.

2. Remove Components for Access

3. Using a 13mm (1/2 inch) socket and ratchet and a 13mm (1/2 inch) combination wrench, disconnect the exhaust headers. Move them back out of the way without fully removing them.
4. Unscrew and remove the oil filter by hand or with an oil filter wrench.
5. Disconnect the wires from the oil pressure sending unit carefully.
6. Use a thin head 24mm (15/16 inch) open end wrench to remove the oil pressure sending unit.
7. Remove the oil pressure relief valve from its housing.

3. Drain the Coolant

8. Follow this link to ensure this step – Coolant System Draining, Filling, and Venting – of the process is followed accurately to drain the coolant from the vehicle.
9. Using a 10mm (3/8 inch) socket and ratchet or a 10mm (3/8 inch) combination wrench, remove the heat shield above the oil cooler housing.

4. Remove the Oil Cooler Housing

10. With a 13mm (1/2 inch) socket and ratchet or a 13mm (1/2 inch) combination wrench, remove the bolts securing the oil cooler housing.
11. Pull off the oil cooler housing and the cooler element together. The old seals might stick to either the housing or the engine block.
12. Remove all old seals from the cooler housing, engine block, and cooler element. The S / S2 uses a single integral gasket (944 107 147 03), replacing the older three-seal setup.

5. Replace Seals and Assemble Cooler

13. Install two new o-rings (999 707 043 40) on both nozzles of the cooler element.

14. Place the plastic washer (944 107 154 00) between the cooler element and the housing, then slide the element into the housing.
15. Lay a straight edge across the top of the cooler housing next to the cooler element guide boss. Measure the distance between the boss lip and the straight edge. It should be 0 ± 0.25 mm (0 ± 0.01 inches). Add shims (944 107 219 00) if needed to adjust this distance. Each shim is 0.5 mm thick, and typically, no more than one is required.

16. Install the rubber seal (944 107 153 02) into the groove on the engine block. Apply a light coat of grease to keep it in place during assembly.

17. Place a new integral gasket (944 107 147 03) on the engine block. Use a dab of grease to hold it steady.

6. Reinstall the Oil Cooler Housing

18. Bolt the assembled oil cooler housing to the engine block using a 13mm (1/2 inch) socket and ratchet. Don’t fully tighten the bolts yet.
19. Follow this link to ensure this step – Oil Pressure Relief Valve – of the process is followed accurately to determine the correct alignment tool (9262/1 for relief valve 944 107 035 02). Insert the tool into the oil pressure relief valve opening to align the housing.
20. Tighten the oil cooler housing bolts (M8) to 20 Nm (15 ft-lbs).
21. Remove the alignment tool and install the oil pressure relief valve. Torque it to 45 Nm (33 ft-lbs).

7. Reassemble Remaining Components

22. Reinstall the oil pressure sending unit using a 24mm (15/16 inch) wrench and tighten to 35 Nm (26 ft-lbs).
23. Reconnect the electrical wires to the oil pressure sending unit.
24. Reinstall the heat shield above the oil cooler housing using a 10mm (3/8 inch) socket or wrench. Torque the bolts (M6) to 8 Nm (6 ft-lbs).
25. Apply a light coat of oil to the seal of a new oil filter and install it. Tighten to 20 Nm (15 ft-lbs).
26. Reattach the exhaust headers using a 13mm (1/2 inch) socket and wrench.

8. Finalize and Check the System

27. If the coolant tank showed a “milkshake” mixture, flush the cooling system thoroughly. Then, follow this link to ensure this step – Coolant System Draining, Filling, and Venting – of the process is followed accurately to fill and vent the system.
28. If coolant may have entered the oil system, change the engine oil, run the engine until warm, then change the oil and filter again.
29. Reinstall the belly pan and lower the vehicle from the jack stands.

Post Procedure Checklist

• Check for oil or coolant leaks around the oil cooler housing.
• Verify the coolant tank is free of oil contamination after running the engine.
• Ensure the oil pressure sending unit is functioning by checking the gauge or warning light.
• Confirm the exhaust headers are secure and not rattling.

Sources

• Clark’s Garage
• Pelican Parts
• Porsche 944 Workshop Manuals
• Youtube