Plenum chamber drain holes

jdp1962

Grumpy Old Man
As the weather cools and we head into autumn, I'm starting to see condensation build up on the inside of the windscreen. That's usually an indicator that the plenum drain holes need clearing; I can do the nearside one pretty easily but how does a sausage-fingered idiot like me access the offside one that is concealed below so much fixed hardware? Does it need to go up on a ramp, have the engine undertray removed and a long stick poked up from below?
 

Tatey14

New Member
Have you got any damp carpets?

I was wondering the exact same thing as after finding damp driver carpets with some heavy rain last weekend. Nearside drain seems find, but I can't even see the offside drain to know if it's blocked.

Can't see any evidence of drips behind the A pillar trim, so can only think its coming through the bulkhead offside.
 

rum4mo

Registered User
My B8 S4 is normally garaged so these drains never get chocked, though, as it ends up parked outside when away from home, I give these drains a checking over every other year, and I'm sure that I can reach the RHS one with something flexible, like a long "grabber" or "net curtain" springy thing that I've bought and used for years for jobs like this and threading through new wiring.
 

RyanJonS4

Drive It Like You Stole It

ld2130

Registered User
I currently have the same issue as my drive is surrounded by trees.
I've just added gutter hedgehogs to my gutters and wondered if I could do something similar for the poor car as it just sitting there most of time these days.
 

audiwaterpump

Registered User
It would help if we knew the exact location of the drivers side drain hole.
Any one got a diagram?
 

rum4mo

Registered User
From memory, maybe not a good idea/servant, it is under the brake servo, which is why you can't see it easily.

I have a "thing" about leaves etc gathering under car bonnets, as they can cause serious issues/costs if not removed frequently.
 

audiwaterpump

Registered User
The drain hole on the driver's side is impossible to get to, without removing a lot of stuff.
Does anyone where the water drains to? Does it drain into the engine bay, or somewhere else?
 

audiwaterpump

Registered User
I'm sure, that both drains just drain through these holes+valves on the base of that plenum area down to the outside world below these points
I was thinking, if we knew where the exit was then I may be able to clear the blockage form the bottom end as opposed to from the top end. - if that makes sense.

The one of the passenger side drains into the engine bay.
 

rum4mo

Registered User
I think that while that sounds like a good plan, in reality, even after removing a couple of under covers, that area, looking up from below, is a bit crowed gearbox /final drive wise.
 

audiwaterpump

Registered User
I think that while that sounds like a good plan, in reality, even after removing a couple of under covers, that area, looking up from below, is a bit crowed gearbox /final drive wise.
Pity that the driver's side one doesn't drain into the engine bay, like the passenger side one.
 

Gooders

Active Member
VCDS Map User
I cleared mine out the other day using an air line and a hover lol. Blow the dirt up and the hover caught it all. Work rather well


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