Oil Cooler General Information and Seal Replacement

Introduction

The first indication of failing oil cooler seals is usually a milky, "milkshake" appearance in the coolant tank — which can also indicate a failing head gasket, but in most cases it is the oil cooler seals. Replace the seals immediately at the first sign of failure. Oil in the coolant is manageable, but if coolant enters the oil system the results are likely catastrophic.

Other Procedures Needed

• COOL-02, Cooling System Draining, Filling, and Venting

Parts

Part Number	Qty	Model	Description
944 107 147 03	1	ALL	Integral Gasket
999 707 043 40	2 *	ALL	O-Ring (Cooler Element)
944 107 154 00	1	944, 944S, 924S	Plastic Washer
944 107 153 02	1	944, 944S, 924S	Rubber Seal
944 107 219 00	As needed	944, 944S, 924S	Shim (0.5 mm)

* Normally-aspirated cars use two o-rings; turbocharged cars use one o-ring. The older-style o-ring was red in colour and has been superseded by a new green-coloured o-ring bearing part number 999 707 040 40. When replacing, always use the new style.

Tools

• Metric socket set
• Metric combination wrench set
• Thin-head 24 mm (or 15/16") open-end wrench
• Alignment Tool 9262/1 — for cars using oil pressure relief valve 944 107 035 02
• Alignment Tool 9215 — for cars using oil pressure relief valve 944 107 035 11

Refer to LUBE-02 to determine which relief valve your car has.

Procedure

1. Place the vehicle on jack stands.
2. Remove the belly pan.
3. Disconnect the exhaust headers (13 mm socket and ratchet, 13 mm combination wrench) and move them rearward out of the way. Complete removal from the vehicle is not required.
4. Remove the oil filter.
5. Disconnect the wires from the oil pressure sending unit.
6. Using the thin-head 24 mm open-end wrench, remove the oil pressure sending unit.
7. Remove the oil pressure relief valve.
8. If the vehicle has an external oil cooler, disconnect the supply and return lines from the oil cooler housing.
9. Using COOL-02, drain the coolant from the vehicle.
10. Remove the heat shield above the oil cooler housing (10 mm socket/ratchet or wrench).

Note: You may find it necessary to remove the power steering pump. Remove the pump from the mounting bracket, leave the lines connected, and hang the pump out of the way.

11. Remove the bolts for the oil cooler housing (13 mm socket/ratchet or combination wrench).
12. Remove the oil cooler housing and the cooler element (on cars with integral oil cooler).
13. When you remove the cooler and housing, the seals may remain attached to either the cooler housing or the block mating surface.

Note: There are two different seal arrangements. In some cases there are three separate seals. In others, a single integral gasket contains all three seals. The three-seal arrangement is the old style and has been replaced by the single integral gasket. In either case, install the current integral gasket (944 107 147 03).

14. Remove all old seals from the cooler housing, block, and cooler element.

15. On normally-aspirated cars, replace the two o-ring seals on both nozzles of the cooler (999 707 043 40).

16. On normally-aspirated cars, install the plastic washer (944 107 154 00) between the cooler element and cooler housing, and slide the element into the housing.

17. Lay a straight edge across the top of the cooler housing next to the cooler element guide boss. Measure the distance between the lip of the boss on the cooler element and the straight edge. The distance must be 0 ± 0.25 mm. Do not install the cooler housing gasket before taking this measurement. Install shims (944 107 219 00, 0.5 mm each) as necessary. Normally no more than one shim is required.

18. On normally-aspirated cars, replace the cooler element rubber mount (944 107 153 02) in the groove on the block. Apply a light coat of grease to the ring to hold it in place during assembly.

19. On normally-aspirated and turbocharged cars, install a new gasket (944 107 147 03) on the block. Apply a light coat of grease to hold the gasket in place during assembly.

20. On turbocharged cars, install a new o-ring on the connector pipe for the oil filter/thermostat housing (999 707 043 40).

21. Bolt the assembled oil cooler (or filter housing on turbocharged cars) to the block. Do not fully tighten the mounting bolts yet.

22. Determine the correct oil pressure relief alignment tool (see Tools above and LUBE-02).

23. Insert the alignment tool into the vacant opening for the oil pressure relief valve to align the housing.

24. Torque the oil cooler housing bolts (M8) to 20 Nm (15 ft-lbs).

25. Remove the alignment tool and install the oil pressure relief valve. Torque the relief valve to 45 Nm (33 ft-lbs).

26. Install the oil pressure sending unit and tighten to 35 Nm (26 ft-lbs).

27. Reconnect the electrical wires for the oil pressure sending unit.

28. Install the heat shield above the oil cooler housing. Torque the heat shield bolts (M6) to 8 Nm (6 ft-lbs).

29. Apply a light coat of oil to the seal of a new oil filter and install the filter. Tighten to 20 Nm (15 ft-lbs).

30. Install the exhaust headers.

31. If seal failure was evidenced by a milky mixture in the coolant reservoir, flush the cooling system thoroughly. After flushing, fill and vent using COOL-02.

32. If there is reason to believe coolant entered the oil system, change the oil, run the engine until warm, then change the oil and filter again.

33. Install the belly pan and remove the vehicle from jack stands.