The test procedures given in the chapter Noise, Vibration and Harshness can also be used to diagnose wind noises.
Road tests
Wind noises can usually only be localized by road tests
NOTE: There should always be two people present during road tests to find noises. A driver who reconstructs the situation causing the noise, and a person to carry out the checks
The following points should be taken into account for such road tests:
If it is difficult to detect the noise sources, the search can be made easier by masking potential areas.
Chalk/powder test
This test checks the contact surfaces of seals on doors, hatches and lids.
Process using a door seal as an example: To do this, the door seal is coated with powder or brushed with chalk. A thin layer of grease is applied to the surface against which the seal makes contact. The door must then be slowly closed and reopened. The width and continuity of the imprint can now be checked on the seal.
Smoke test
Flow checking device
Item |
Description |
1 | Test pipe |
2 | Test pipe opener |
3 | Puffer ball |
Mode of operation: The flow checking device is a set made up of a flow-testing pipe, a test pipe opener, puffer ball and closing-off caps for the pipe.
The test pipe contains a filling layer which is impregnated with fuming sulfuric acid. When air is blown through the pipe by the puffer ball, sulfuric acid aerosol is emitted in the form of a white smoke.
NOTE: Pay attention to the instructions for use and the safety directions issued by the manufacturer.
The smoke test can only be performed in a draft-free environment.
This test can be used to detect leaks visually.
Procedure:
Ultrasonic test
This test searches for leaks in the system of seals or rather acoustic bridges. When an ultrasonic transmitter is placed inside the vehicle, it sends out ultrasonic waves. A leak is located by running a detector along the suspected area. The position with the loudest reception of the escaping ultrasonic waves indicates places where noises occur.
Ultrasonic test device
Procedure:
Stethoscope test
Stethoscope