Compressor, 6-Cylinder

Compressor, 6-Cylinder

• Mark connector to A/C Compressor Regulator Valve (N280) due to risk of interchange with connector to electric engine mount (if connectors are interchanged, no DTC is entered in DTC memory, however the evaporator may ice-up since the compressor is actuated continuously).

• In vehicles with an electric engine mount, ensure the proper allocation of connectors at the engine mount and at the A/C Compressor Regulator Valve (N280), these components have the same connections. If the connectors are transposed, an error will not be stored (the components have approximately the same electric values), the engine mount will be actuated by the Climatronic Control Module (J255), and the A/C Compressor Regulator Valve (N280) by the Engine Control Module.

Removing

- Drain the refrigerant circuit.

- Disconnect refrigerant lines from compressor => [ Refrigerant Lines, Disconnecting and Connecting at Compressor ] Refrigerant Lines, Disconnecting and Connecting at Compressor.

- Remove the compressor from the holder => [ Compressor with Pulley, Removing and Installing at Bracket ] Compressor with Pulley, Removing and Installing at Bracket

• Seal open pipes and connections at condenser with suitable caps (to prevent dirt and moisture from entering).

Installing

Installation is carried out in the reverse order, noting the following:

- Install the compressor on the holder => [ Compressor with Pulley, Removing and Installing at Bracket ] Compressor with Pulley, Removing and Installing at Bracket

• Tightening torque for the screws between the compressor and holder => [ Compressor with Pulley, Removing and Installing at Bracket ] Compressor with Pulley, Removing and Installing at Bracket.

• An uncertain quantity of refrigerant oil remains in a removed compressor, therefore observe notes for replacing the compressor.

• Start the engine first after reconnecting the refrigerant circuit.

• If possible start engine only with a filled refrigerant circuit.

- Replace the O-ring seals on opened connection points, version

- Install the refrigerant lines on the compressor => [ Refrigerant Lines, Disconnecting and Connecting at Compressor ] Refrigerant Lines, Disconnecting and Connecting at Compressor

- After installation, manually turn the compressor 10 rotations before positioning the ribbed belt (to prevent damage to the compressor when it is first switched on).

If the engine must be started when the refrigerant circuit is empty, perform the following steps to prevent compressor damage => [ A/C System, Operating after Filling Refrigerant Circuit ] A/C System, Operating after Filling Refrigerant Circuit

• By rotating, refrigerant oil which has accumulated in the compressor compression chamber in the removed compressor or after adding fresh refrigerant oil (e.g. after blowing through the refrigerant circuit) is forced out of the compression chamber.

• Different compressors, depending on country variants and the engine.

• Coat O-ring seals lightly with refrigerant oil before installing.

• The compressor is always driven by a pulley/the drive unit. There is no magnetic clutch.

• The compressor has an "internal oil circuit" to ensure the compressor is not damaged when refrigerant circuit is empty. Prerequisite for the internal lubrication is residual refrigerant oil in compressor. As there is no refrigerant in the circuit, the oil required to lubricate is not fed to the compressor.

• The engine may only be started when the refrigerant circuit is installed correctly. If for example the refrigerant lines are not connected to the compressor and the engine is started then the compressor may be destroyed by the build-up of internal heat.

• A/C Compressor Regulator Valve (N280) is not activated when the refrigerant circuit is empty and the compressor idles with the engine.

- Empty and fill refrigerant circuit.

- Check DTC memory of A/C control head Climatronic Control Module (J255) and erase malfunctions displayed if necessary.

- Operate the A/C system after filling the refrigerant circuit => [ A/C System, Operating after Filling Refrigerant Circuit ] A/C System, Operating after Filling Refrigerant Circuit