Sluggish Manifold Flaps Guide

[steamship]

In the D2 repair sticky, there is a link to a writeup on the quattroworld forum about sluggish or stuck manifold flaps. This is the link below:

40V Intake manifold fix for stuck or sluggish flap pivots (no broken parts)

Unfortunately, that site is no longer available, and I was wondering if anyone ever saved the details, including the photos. I've used the Internet Archive and can get the text, but none of the photos are there.

EDIT: I just did some more searching, and it appears the site is still available. It is just this one specific post that has been deleted. Still on the hunt for photos.

[johnny_quattro]

just found these nuggets, care of the trusty WaybackMachine (no photos though):

40V Intake manifold fix for stuck or sluggish flap pivots ( w/no broken parts )...
Posted by: silverd2 (9538) on 2011-03-06 16:52:20
In Reply to: Engine Mechanical posted by PaulW on 2009-12-01 14:38:37

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A common problem that disables an otherwise very effective torque curve extender.

Here's how it's supposed to work:


vv- The results -vv
You can see what would happen to engine torque if any stage was not working...well worth the trouble to get it freed up and working.


With engine off, the actuators should look like this. Both levers held against stops by springs...vacuum pods inflated. Should go to this immediately (not slowly) when engine is switched off. If not, they are seized or too sluggish.


When engine is started, they should go immediately (not slowly) to this. Both vacuum pods evacuated and both levers pulled away from stops fully, against spring tension. If not, your intake manifold changeover is not operating properly and you're missing out on the full effect of a really cool system...losing torque in some part of the rpm range.




Bentley has nothing on this, because Audi says the system cannot be repaired and the entire manifold needs to be replaced...not so.

Before you start, take photos or make notes about vacuum connections/routing. Also, if I need to to tell you individual tools, sizes and micro details for each step (except as noted/shown), you don't need to be tackling this job. It's not terribly difficult but includes a couple of "delicate" steps and a little "feel" required for things you can't see without taking the manifold apart (NOT necessary).
"Greg's" post (see link at bottom of page) in the FAQ Digest has photos of the manifold's interior, to help visualize how the other end of the "flap rods" fit into the pivots on the far end of the manifold. You'll have to feed them back into these when reassembling...it's blind, but very possible...I've done it a few times. You can actually see the top pivot hole back inside the manifold, looking in with a flashlight, while the upper flap rod is out of that pivot, but it is a blind fit when it comes time for reassembly.



First remove top vacuum pod and ball joint link...can pry ball joint off manifold actuating level with a wide flat screwdriver.


Disconnect elec connection to bottom left actuator valve and unbolt (one) from manifold.


Remove valve with hoses attached.


After disconnecting upper right actuator valve and removing with hoses attached, remove lower vacuum pod with ball joint link.


Time to take the plastic lever off the top pivot..center allen bolt. I recommend completely repairing the upper one, before disassembling the lower one. I found that the internal flaps can interfere with each other when both are free at the same time. Lower stays out of the way of the upper if left under spring tension.


Take note, before removing aluminum pivot casing (2 torx bolts), that the smaller triangle stop (next to upper torx bolt) needs to be at top...must reassemble this way...same on upper and lower pivots.


Pull casing out just far enough to get something behind it...there's enough play on the other end (inside manifold) to start "tapping" it out. At this point, of course, if you have the proper gear puller (I don't...used what I had), you could carefully press/pull outer pivot casing off plastic spindle end.


The first few mm's are the toughest..helps to put lever back on and rotate a little a few times. The right gear puller would indeed be ideal for this, but....


I went with progressively thicker back-stops (see crescent wrench), to assure rear clearance to continue driving the casing off the spindle. Be patient and GENTLE!! If it's seized or very sluggish, it's gonna be tough to tap off...baby steps...you DON'T wanna break it!!


There's your problem part...corrosion/build up/schmutz on the inside of the outer race casing.
Notice the plastic spindle in the manifold (end of internal "flap rod") is out as far as it will go...out of the hidden inside pivot hole on other end of the manifold.
I carefully cleaned the plastic spindle with a plastic brush wheel on a Dremel...not much build up there...just clean it.


Notice the tiny lip seal inside casing...rides on raised inner lip at base of plastic spindle end. Be very careful not to damage this or outer o-ring to assure no vacuum leaks.


I found cleaning alone was NOT enough in the outer aluminum pivot casing. I used a soft (carbon steel) wire wheel on a Dremel, being careful NOT to damage the little lip seal. Do a little at a time and test fit it on the plastic spindle...snug, but easy turning on the spindle is as far as you want to go. I used the wire brush just to the point of getting a shine and it was a perfect fit.


I coated the spindle end and inside of outer pivot race with a thin coat of silicone grease. Reassemble by fishing "flap rod" back into rear pivot, put outer casing on spindle, torx bolts back in (taking care that small triangle stop is up).
Photo shows levers test fitted correctly with flaps free to fall into place under gravity.
Notice that the lower lever will be harder to tension spring far enough to fit casing onto spindle correctly.
Note reminder: You may have to assemble lower pivot/lever (including spring in place) before fishing upper "flap rod" into rear hole. If the lower flap rod is out of inner pivot and/or out of spring loaded position, it "can" interfere with upper flap rod fitting into place.


With spring on lever, fit end of spring into lower slot (out of view).


Not easy, but turn lever clockwise back against spring to this position so that lever engages spindle at it's proper "rest" point. Push on and replace allen bolt.


Upper lever is much easier to fit. Spring in slot, then turn clockwise just past lower triangle stop and it should slide onto spindle there. Push on and bolt.


Replace lower right vacuum pod and press ball joint link back together.


Replace upper right actuator valve w/hoses and elec plug.


Replace lower left actuator valve w/hoses and elec plug. Then replace upper left vacuum pod and press ball joint link back together.


Make sure all your hoses are routed and back on correctly (and snug)...elec plugs on valves, too.

Put your engine cover back on.

Start it up and take a drive...don't forget to close the hood

Take it up to redline a few times and see what ya think.
http://forums.quattroworld.com/a8/msgs/22072.phtml

[steamship]

Originally Posted by johnny_quattro

just found these nuggets, care of the trusty WaybackMachine (no photos though):

Thanks, but as I did state in my original post, I already have the text, obtained the same way.

[Architex_mA8tey]

I may have the original drawings saved as a pdf but would need some time to search
James did the flap fix on my D2 many years ago after me and Reffro compared flaps at the first AITPand mine were sticking - I can remember copying the whole thing onto PDF and sending him a copy

[johnny_quattro]

Steamship, I got all excited and didn't twig about the Internet Archive as I've always known it as the Wayback Machine. Still, useful info to include in the post for future searches. Let's hope Architex-mA8tey can find that elusive PDF with photos.

I'll admit to having a vested interest here due to my recent cam cover gaskets problem. These are now sorted at the second attempt and whilst the vanity covers were off the engine, I took a look at those bellows and noted that the top one on mine seemed to have some kind of repair effected on it (it looks like someone has had a go at this before and smeared some black silicone sealant on the outside casing).

My bellows seem to be inflated all the time but when the engine is running, they suck in gently but only by a few millimetres. I can pinch one of the attached rubber hoses to see the slight movement. It's definitely not working as intended so I'd like to attempt this repair.

[MikkiJayne]

Can you move the arms by hand? Often the braided vacuum hoses perish and you lose the vacuum which drives this system, so the pods and arms may be fine but there's nothing to make them move.

[David's8]

I have the Audiworld pages for this repair complete with colour piccies. Its 16 pages long and Ill need to scan it to pdf.

It'll cost you Sean

[David's8]

Here you are.

[27litres]

Silverd2 (Sam) has posted this on Audiworld and Quattroworld.
Edit: he posted it on QW and linked to it on AW.
For some reason it's been deleted from QW. Don't know why, but he appears to have left the building (on both forums).
I'm glad someone saved it and for the wayback machine...

And I think Gruven copied the whole thing onto their site too as a DIY.
Edit: link here to Gruven DIY (copied from QW) as a pdf

It's all out there somewhere.

[steamship]

Originally Posted by johnny_quattro

Steamship, I got all excited and didn't twig about the Internet Archive as I've always known it as the Wayback Machine.

No problem, I always knew it as the Wayback Machine as well.

Originally Posted by MikkiJayne

Can you move the arms by hand? Often the braided vacuum hoses perish and you lose the vacuum which drives this system, so the pods and arms may be fine but there's nothing to make them move.

They move by hand, the pods are intact and the vacuum hoses were all replaced a couple of years ago. I was searching for something on the forum and came across an old post of mine, where I mention that they seem to work fine (after filming them), but when you give some throttle, one of them is slower that t'other.

Originally Posted by David's8

Here you are.

Fantastic! I owe you one, or two.

Originally Posted by 27litres

Silverd2 (Sam) has posted this on Audiworld and Quattroworld.
Edit: he posted it on QW and linked to it on AW.
For some reason it's been deleted from QW. Don't know why, but he appears to have left the building (on both forums).
I'm glad someone saved it and for the wayback machine...

It's all out there somewhere.

It was from AW that I first came across it, and when the link didn't work, that's why I thought that the QW site had gone.

As ever, thanks to everyone.