Special Tools
Warning: Refer to Assistant Driving Warning in the Preface section.
To analyze a reported windnoise condition, test drive the vehicle to determine the origin of the noise.
Choose a regular route with smooth and straight streets that run in all 4 directions: North, South, East, and West. The area should have little traffic or little noise in order to eliminate interference with the test.
Note: Often there is one primary leak source and one or more secondary leaks that contribute to the noise condition. Repairing only one of the contributing leak sources may not completely repair the total condition but only reduce the condition.
Drive the vehicle at the speed in which the noise was noticed, or until the noise is heard. Maintain safe and legal speeds.
Many of the waterleak diagnosis tests are also used for the windnoise diagnosis.
Most windnoise is caused either by leaking seals or by misaligned body surfaces. You can diagnose the following types of windnoise with the aid of CH-39570 Chassis Ear or GE-41416 Leak Detector .
When moving at highway speeds, air pressure inside the vehicle becomes greater than the air pressure outside. When a leak occurs, the escaping air causes a hiss or a whistle.
Wind roar occurs when air passes over or through an opening between the 2 body surfaces. To correct the condition, adjust the alignment to the body surfaces.
Wind rush occurs when air presses over the vehicle's body, and is related to the aerodynamics of the vehicle. Wind whistle and wind roar are repairable. Rule out wind whistle and wind roar before concluding that the wind noise is due to wind rush.
Use the following inspections in order to aid in diagnosing wind whistle or wind roar:
Lifting and Jacking the Vehicle
Tracing Powder or Chalk TestMetric Fasteners
This vehicle provides fastener dimensions using the metric system. Most
metric fasteners are approximate in diameter to equivalent
English fasteners. Make replacements using fasteners of the same nominal
diameter, thread pitch, and strength.
A number marking identifies the OE metric fastener ...
Water Management Description and Operation
Plenum Water Flow Direction and Cleaning
A large percentage of water will flow off the windshield area into the plenum
chamber drain system and then down the outside on the
plenum to the underside of the vehicle. To ensure that the plenum chamber water
management system performs properly, the ...
Brake Fluid
The brake/clutch master cylinder reservoir is filled with DOT 3 brake fluid as
indicated on the reservoir cap.
There are only two reasons why the brake fluid level in the reservoir might go
down:
• The brake fluid level goes down because of normal brake lining wear. When new
linings are in ...