Noise may be coming from the engine compartment in the above vehicles when the engine is running at operating temperature. This occurs in particular during acceleration of the vehicle and an engine speed between 2000 and 3000 rpm.
The cause may be a missing or misplaced damper strip between the frame rail and the refrigerant line (see image).
Make sure that the damping strip is present and correctly installed. If necessary, attach a new damping strip. When doing so, make sure that the refrigerant line does not come into contact with the frame rail.
Otherwise, the flow noise of the refrigerant may be transmitted through the body into the vehicle interior. It is important to ensure that the damping strip extends approx. 5mm beyond the edge of the frame rail.
Note: A suitable damping strip is Hella part no. 9MJ 351 018-011
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.
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