Plenum Chamber Water Drain, Checking
WARNING: This page is about a different car, the 2021 Audi S4 and 2021 Audi A4 Quattro. However, it is still accessible from the selected car via links, so may be relevant.
-- Remove the plenum chamber cover -A-. Refer to PLENUM CHAMBER COVER, REMOVING AND INSTALLING .
- To prevent water from running via intake shaft -B- into the heater and A/C unit when plenum chamber cover -A- is installed, the plenum chamber cover -A- must not be damaged. In addition the plenum chamber cover -A- must be correctly and completely engaged in the windshield frame -C-.
- The draining of water from plenum chamber -A- may be impaired by deposits (leaves, various tree needles, etc.) accumulating in plenum chamber water drains -D- (or in the opening -E-). The water level in plenum chamber then rises if the vehicle is taken to an automatic car wash or in the event of heavy rain. Water enters via the air intake shroud -B- into the heater and A/C unit and is blown by the Fresh Air Blower -V2- together with the conveyed air into the dust and pollen filter and onto the evaporator.
- If opening of the water drains -E- (right and left in plenum chamber respectively) are blocked by leaves and pine needles, it may cause the water drains to freeze up in winter and water can no longer drain out. After a short drive, heat emitted from engine and exhaust system melts the ice in the drains again and water may drain off again before vehicle arrives at the workshop.
- If the water drains -D- (one right and left in the plenum chamber respectively) or the plenum chamber itself is contaminated with leaves and pine needles, this can lead to complaints when operating the heating and A/C system do to odor.
- Both water drains -D- are currently without valves, the water flows via the openings -E- in the area of the rear, right, and the left front wheel housing liner.