Plenum drain = Cowl drain? Drains for air box? Suggestions?
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Plenum drain = Cowl drain? Drains for air box? Suggestions?
This might just be a case of terminology...
As I mentioned in the thread below, the Audi dealer found that clogged "plenum drains" & the worn air box intake seal were causing water to get in through the heater box intake. The "official" fix would be to reseal the air box intake -- a procedure that involves taking off the dash, etc. They sketched a diagram of how the water rises and gets in. The repair would be over $1,500.
When I asked if there were any "unofficial" fixes, it was mentioned that it would be worthwhile checking online with DIY A8 owners. An offhand comment was something like, "I don't know whether a couple of 1/8" holes in the plenum would help or hurt."
I've checked the Audipages drain cleaning section and found references to the A/C evap drains & the "cowl" drains. Are either of these what the dealer calls "plenum drains?"
Does anyone have the Audi factory instructions for clearing the "plenum" and/or "cowl" drains?
As I mentioned in the thread below, the Audi dealer found that clogged "plenum drains" & the worn air box intake seal were causing water to get in through the heater box intake. The "official" fix would be to reseal the air box intake -- a procedure that involves taking off the dash, etc. They sketched a diagram of how the water rises and gets in. The repair would be over $1,500.
When I asked if there were any "unofficial" fixes, it was mentioned that it would be worthwhile checking online with DIY A8 owners. An offhand comment was something like, "I don't know whether a couple of 1/8" holes in the plenum would help or hurt."
I've checked the Audipages drain cleaning section and found references to the A/C evap drains & the "cowl" drains. Are either of these what the dealer calls "plenum drains?"
Does anyone have the Audi factory instructions for clearing the "plenum" and/or "cowl" drains?
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Re: Plenum drain = Cowl drain? Yes, correct.
Click on the A8 line in my sig. There's a set of instructions for cleaning both the cowl/plenum drains, and the A/C evap drains, at Audipages.
You may genuflect in the direction of Chicago, in homage to PaulW, after bookmarking Audipages.
You may genuflect in the direction of Chicago, in homage to PaulW, after bookmarking Audipages.
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From: Wilbur by the Sea
$1500? I'll do it for tree fiddy
That would be the easiest $350 I ever made. Follow the procedures on audipages and with the money saved, have a few bottles of high end champagne on me!
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There are 4 cowl drains, and 2 evap drains.
The evap drains are on each side of the driveshaft hump, in the footwell.
Your air seal is not "worn". Every A8 leaks there. It's just bad design. Pay them the money, and the next time the drains clog it will STILL LEAK. Hell man, if it fills up enough, the water comes pouring out of the rear passenger air vents!!
The 2 easy to access cowl drains are in each front tire wheel well. You can see them rather easily with a flashlight.
The 2 center cowl drains are more problematic, since they are hidden from above and exit over the transmission .. completely hidden from both sides.
You have to use an piece of bent copper or aluminum tubing as an extension for an air hose, and snake it down into the plenum until you find the 2 vents, then blast them good.
The only long-term fix is to garage your A8! Stop getting leaves in your airbox 8)
Your air seal is not "worn". Every A8 leaks there. It's just bad design. Pay them the money, and the next time the drains clog it will STILL LEAK. Hell man, if it fills up enough, the water comes pouring out of the rear passenger air vents!!
The 2 easy to access cowl drains are in each front tire wheel well. You can see them rather easily with a flashlight.
The 2 center cowl drains are more problematic, since they are hidden from above and exit over the transmission .. completely hidden from both sides.
You have to use an piece of bent copper or aluminum tubing as an extension for an air hose, and snake it down into the plenum until you find the 2 vents, then blast them good.
The only long-term fix is to garage your A8! Stop getting leaves in your airbox 8)
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Thanks for info. I actually do garage my car @ home, but...
since I live in a semi-rural area of WA, there are plenty of opportunities to be near trees and bleepin' pine needles the rest of the time.
What about Angus' suggestion of clipping the cowl / plenum drain ends?
What about Angus' suggestion of clipping the cowl / plenum drain ends?