Test Information

Fig. 8 Applying Tracing Powder:

If you have completed the road test and haven't been able to pinpoint the source of an internal wind noise, there are several additional diagnostic tests you can perform in the shop.

TRACING POWDER/CHALK:

One of the simplest and most effective checks for weatherstrip leaks is the tracing powder or chalk test.

First, clean the weatherstrip with solvent cleaner. Next, apply the powder or chalk to the weatherstrip's mating surface, as shown in Figure 8.

Fig. 9 Gap in Tracing Powder Imprint:

Press the panel against its mating surface firmly, without slamming, closing it completely. When you reopen it, there will be an imprint left whenever the weatherstrip made good contact with the mating surface. Gaps in the imprint indicate a poor seal. Refer to Figure 9.

Fig. 10 Escaping Air Forms Bubbles:

SOAP BUBBLE:

On the road test, you taped the pressure relief valves and shut the doors and windows to create higher pressure inside the vehicle. By turning the interior fan on HIGH, you can create a similar condition in the shop.

You can then spray a soapy solution along the outside of the suspected area. If air is escaping from an area, bubbles will form, as shown in Figure 10.

Fig. 11 Listening With Sonic Detector:

SONIC DETECTOR:

Another method which doesn't involve taping the relief valves and turning on the fan uses a sonic detector to pinpoint leaks.

Place the tone generator inside the vehicle and listen with the detector along the door and window seals, as shown in Figure 11.