Removing and Installing/Replacing Front Exhaust Manifold

18 40 050 - Removing and installing/replacing front exhaust manifold (N52K)





Warning!
Risk of injury!
Refrigerant circuit is under high pressure!
Follow safety instructions for handling refrigerant.
Avoid contact with refrigerant and refrigerant oil
Follow safety instructions for handling refrigerant oil [1][2]64 50 ... Safety Instructions for Handling Refrigerant Oil.





Important!
Risk of damage!
Restart engine only when A/C system has been correctly filled.
Follow instructions Removal and Replacement for opening and replacing parts in refrigerant circuit.
If A/C system is opened for more than 24 hours:
Replace desiccant insert Service and Repair for A/C system.





Necessary preliminary tasks:
- Remove rear exhaust manifold Removing and Installing/Replacing Rear Exhaust Manifold
- Drain off air conditioning system 64 50 010 Drawing Off, Evacuating and Filling A/C System (R 134a)





Note:
The oxygen sensors are in danger of being damaged when the exhaust manifolds are removed and installed.

Remove control sensor 11 78 513 Replacing Both Oxygen Control Sensors from cylinders 1 to 3.

Remove monitor sensor 11 78 545 Removing and Installing/Replacing Monitor Sensor from cylinders 1 to 3.





Release screws (1).
Tightening torque 64 52 1AZ [1][2]Compressor HVAC.
Detach pressure and suction lines from A/C compressor.

Installation Note:
Replace all sealing rings and moisten with refrigerant oil.





Unscrew nuts.
Remove exhaust manifold (1).

Installation Note:
Clean sealing faces and replace seals.
Replace nuts.
Tightening torque 18 40 1AZ 18 40 Exhaust Manifold.





Assemble engine.
Evacuate and fill A/C system 64 50 010 Drawing Off, Evacuating and Filling A/C System (R 134a).
Check exhaust system for leaks.