Checking, cleaning, removing and installing plenum chamber water drain — AUDI

Checking, cleaning, removing and installing plenum chamber water drain
Note
Drainage of water out of plenum chamber may be impaired by deposits such as leaves and pine needles accumulating in the water drains. If the vehicle is then driven through a car wash or in the event of heavy rainfall, the water level in the plenum chamber will rise and water ingress via the fresh-air intake
A
into the air intake unit
B
.
The water drain hose
C
is intended to discharge the small amounts of water entering the air intake unit via the fresh-air intake in normal operation.
The water drains via the water drain hose
C
out of the plenum chamber (via connection
D
) into the transmission tunnel in the area behind the noise and heat insulation mat (a hole is provided specifically for this in the bottom of the plenum chamber).
A plastic element
D
for reducing the cross-section is inserted in the water drain hose
C
. If plastic element
D
is not fitted, noise may occur depending on
fresh-air blower
V2
speed.
The water drain socket
C
is accessible after removing the
alarm horn
H12
of the anti-theft alarm
B
. The water drain socket
D
is not accessible with the brake servo and air intake unit
A
in position.
If the water drain sockets
C
and
D
are clogged with leaves and pine needles, the drains may freeze up in winter and prevent water drainage. After driving a short distance, the heat emitted by the engine and exhaust system causes the ice in the drains to thaw again. It is possible that the water will have drained off from the plenum chamber again by the time the vehicle arrives at the workshop.
The water drain socket
C
can be cleaned for example after removing the
alarm horn
H12
of the anti-theft alarm
B
(removing
alarm horn
H12
Rep. Gr.
96
Electrical system
).
Coarse dirt can be removed from the water drain socket
D
using a commercially available flexible gripping tool for example. Fine deposits and sludge can be removed for example using a thin water hose or a
pressure-feed spray gun
V.A.G 1538
and a
nylon probe
V.A.G 1538/2
.
If one of the two water drain sockets
C
or
D
is blocked and there are leaves, for example, in the plenum chamber, remove coarse dirt from the area beneath the air intake unit using a commercially available flexible gripping tool for instance. Fine deposits and sludge can be removed for example using a thin water hose or a
pressure-feed spray gun
V.A.G 1538
and a
nylon probe
V.A.G 1538/2
.
To stop water from the plenum chamber flowing via the water drain hose
E
into the air intake unit, the hose ends in the area behind the noise and heat insulation mat in the transmission tunnel.