A/C Question

[Drivingman]

I just purchased a 2011 BMW 328i Convertible and it not blow cold air with the A/C on. I evacuated the system and it held a vacuum. I put in 22 oz of 134A just has the sticker on the hood stated. Now the A/C blows cold air. I never heard the compressor cycle. I checked the compressor and it never shuts off. I turned the temp controls to 80 degrees and the compressor still runs. Does this sound correct? Does the compress run all the time?

[relative4]

Yes and no. The compressor is always spinning, but it is not always compressing. It does not have a clutched pulley. It has an internal swashplate operated by a solenoid to vary piston travel. This allows for variable compression, as opposed to an old-style compressor's on/off operation.

[jclausen]

Exactly

[Drivingman]

Thank you. Good to know.