The vehicles mentioned above may experience noise from the compressor following a cold start of the engine.
This problem is especially common at low temperatures. In such cases, the noise is not necessarily an indication of a defective compressor.
These vehicles are generally fitted with vane compressors. Low temperatures can cause liquid refrigerant to get into the compressor, resulting in a knocking noise shortly after the engine has been started.
Once the motor has been running for a short time, gaseous refrigerant is sucked in again and the noise goes away.
This is a result of the design and weather conditions, not a technical defect.
Important safety notice
The following technical information and tips for practical use have been set up by HELLA in order to offer professional support to automotive workshops in their daily work. The information available here on this website is only to be used by appropriately trained specialist staff.
The reprinting, distribution, reproduction, exploitation in any form and disclosure of the contents of this document, even in part, is prohibited without our express written approval and indication of the source. The schematic illustrations, figures and descriptions are for explanation and presentation of the document text and cannot be used as a basis for installation or design. All rights reserved.
Not helpful at all
Very helpful