Plenum Chamber Water Drain, Checking
The draining of water from plenum chamber may be impaired by deposits (leaves, various tree needles, etc.) accumulating in the plenum chamber water drains -arrows- and in the grommets -1-. The water level in the plenum chamber then rises if the vehicle is taken to an automatic car wash or in the event of heavy rain, water enters via intake housing into the A/C unit and is blown by the fresh air blower onto the evaporator together with the air conveyed.
In the illustration, the water drains -arrows- and the grommets -1- with the water drain valve are shown on the driver side with a removed brake booster.
If the water drains -arrows- and/or the grommets -1- with the valve are blocked by leaves and pine needles, it may cause the 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 shop.
Water can flow into the fresh air intake duct if the cowl panel trim -2- and/or plenum chamber cover -1- are damaged or incorrectly installed. Complaints due to odor problems coming from the heater/A/C system and/or there is moisture in the passenger compartment may result.