Heat Exchanger: Service and Repair

NOTE: Before disconnecting the battery, it is recommended to read out the fault memory of the DME control unit using System Tester 9288. Thus any irregularities can be taken into account during the subsequent assembly jobs, if required.




1. Disconnect battery.
2. Remove rear spoiler.

Loosen the following items:
- Screen
- Nut (4 pcs)
- Sheetmetal screw
- Light assembly
- Pan head screw (3 pcs)
- Bracket
- Closing panel
- Oval-head sheetmetal screw (B 4.8 x 16) Washer 5 x 26 x 1
- Combination screw (6 pcs)
- Rear spoiler
- Seal
- Hexagon nut (9 pcs)
- Heat shield of closing panel
- Sheetmetal screw (4 pcs)
- Washer 5x26x1 (4 pcs.)
- Pan head screw (2 pcs)
- Washer (2 pcs.) A 13
- Bumper support

3. Remove engine underside tray.




4. Remove sealing frame and charge air cooler. While doing so, do not drop the square fastening nuts of the lower charge air cooler bracket.
Plug-seal pressure hoses immediately against foreign substances




1 - Oxygen sensor ahead of cat. conv.
2 - Oxygen sensor behind cat. conv. (cylinder bank 1-3)




1 - Oxygen sensor ahead of cat. conv.
2 - Oxygen sensor behind cat. conv. (cylinder bank 4-6)

5. Unplug, unlock and separate oxygen sensor connections.

6. Extract rubber sleeves from engine paneling and pull wires down. Detach wire clamps from bracket.

NOTE: The rubber sleeve of the right-hand oxygen sensors is hard to access. Remove A/C compressor from bracket and put it aside.

7. Remove muffler.
8. Detach catalytic converter from turbocharger and remove it.
9. Disconnect pressure hoses from turbocharger (compressor side). Seal turbocharger immediately.
10. Loosen two pan head screws (M6 x 12) on the right-hand, lateral engine paneling (accessible from top).
11. Drain oil at turbocharger/oil tray.
12. Loosen oil return line between turbocharger/oil tray and bracket. Loosen bleeding line between turbocharger/oil tray and upper intake pipe.
13. Remove intake hose between turbocharger and intake pipe.

WARNING: (Risk of Injury!). Do not use a screw driver as a lever to disconnect the hose as the vacuum control unit might get damaged!

14. Cut the control hose right behind the vacuum control unit fitting. Use a sharp knife to open the remaining hose.
15. Loosen pan head screws (M8 x 18) between turbocharger bracket and cam- shaft housing.
16. Loosen turbocharger mounting point (combination screw M8 x 16).
17. Remove hoses between heat exchanger and heating flap box.
18. Loosen fastening nuts (M8) of heat exchanger and remove heat exchanger and turbocharger.

NOTE: Two persons are required to detach and remove the turbocharger/heat exchanger assembly.

19. Remove heat exchanger from turbocharger.