2. The filter is checked visually.
3. Open the hood and locate the buffer flap in the air filter (see photo). The damper is located in the long extension of the metal air filter housing.
4. On some vehicles, disconnect the flexible ventilation duct from the filter nozzle.
5. The check is performed on a cooled engine. Start the engine and use a mirror to make sure that the damper is closed. When the damper is closed, air passes through the hose, bypassing the channel near the exhaust manifold, in which the air is heated.
6. As the engine warms up, the damper should open, allowing air to enter through the nozzle. Depending on the outside temperature, the damper will open within 10-15 minutes. To speed up the check, you can take a short drive.
7. If the air filter flap does not operate, follow the steps described in Chapter 6.
[The original text can be found on the website «CHEVYMAN»]