S8 V10 Flaps Delete (Intake Manifold)
 

Here it is, for everyone who suffers or may suffer in the future from a broken intake manifold flap/s.
This is an alternative to couple of £k manifold or a repair (£250) which I was going to do by sending the manifold to an engineer Ron knows, but decided nlt to purely as he couldn't provide any pictures of the repair so I can see how well this is done.

And this was the reason for it, one flap broken of laying at the bottom of the manifold and second one hanging up in the air.
http://forum.a8parts.co.uk/attachmen...1&d=1473973805

Oil separator was faulty hence a bit more than usual of filth inside the manifold.

Prons:
- more engine growl
- louder exhaust
- BHP gain at the higher revs
- huge satisfaction from doing it yourself

Cons:
- slight loss of BHP at the very low end of revs, but not noticeable on this powerful engine. After talking to remap place this loss can be easily recovered with the remap on the dyno which is my next step but also you will double gain BHP on the higher revs.

I followed this guide in order to remove the manifold.
http://audirevolution.net/forum/index.php?topic=3221.0

Please note:
- Inlet wont come out just like that like this guy claims
- You will have to remove both fuel pumps, one on each side of the manifold
- Remove two the most obvious and easiest to undo fuel lines and move them aside.
- This is the worst part which he did not mention at all, unless someone had his manifold out before and did not bother to bolt on the electrical connectors bracket for the fuel injectors which is bolted by two torx bolts to the bottom/front manifold and which will prevent you from removing the manifold.
You WILL NEED a pair or small hands, lots of patience and this mini ratchet with a torx bit (T25 or T30) on the end to unbolt the bracket. This is one of them bolts I've dropped and recover using endoscope camera and grap tool. Both bolts are visible thru the square cut out with the pin in the middle of the crash frame where the bonnet's latch goes.
http://www.screwfix.com/p/titan-scre...questid=550707

Now, this is where it gets interesting as manifold is made from a tough mix on magnesium, zink and aluminium which is also fragile to chips/possibly even cracks when you try to lever it while splitting to hard. That is mainly due to the silicon gasket being very very strong which was applied at the factory not only around the edge but also around each inlet and internal ribs for each intake channel.

Patience, patience, lots of patience, swearing in between and sweat running down your back.
First attempts on the bench where a complete failure even with my mate giving me a hand so time came for attempt no. 2, screwing the manifold to a pallet I quickly made for the engine which fits under my engine hoist. This was the way to go.
http://forum.a8parts.co.uk/attachmen...1&d=1473973805

Tools:
- Torx bit
- heat gun
- thin ish but as wide as possible flat head screwdriver (worth thinning the end off slightly with a grinder)
- stanley knife
- WD40 Specialist Fast Acting Degreaser (for decoking/cleaning the inlet channels and variable inlet flaps) together with few green scouring pads
- 2-3 packs of plastic spudgers for removing the silicon from the grooves
http://www.ebay.co.uk/itm/3-X-PCS-PL...EAAOSw6btXRmwk
- couple of small brass wire brushes for removing fine pieces of silicon seal left behind and final preparation of surface for resealing (it's much harder with the big brushes)
https://www.amazon.co.uk/175MM-BRUSH...wire+brush+set

Splitting is the worst part so as soon this task is done rest is just a time consuming job.

Front right corner is the best place to start as the ridge/grove which is all round the manifold is only set back 2-3mm from the edge and this particular corner and front of the manifold has approx 8-10mm of flat surface before the ridge.

You will only be able lift a tiny section, cut only some of the seal and when you get as far as approx. 1/3 of the way down the side its worth lifting the corner again and wedging and leaving a second screwdriver.
Don't know if that helped much, but I was heating up the manifold from the inside by blowing high temp down the whole where the T piece is bold on.

I only done once and for the first time in my life so can't give you a better advice unfortunately. I haven't seen anyone splitting it before either, but all I can say its doable without damaging it +++

There are 26x torx bolts you will have to undo, 10x at the top around the edges and 16x from the bottom

Here is the manifold with the bottom part removed.
All the black/grey stuff around each groove is the silicon gasket, there is plenty of it around to be removed.
You can also see how the exits to each inlet on the engine are coked up as well (part I mentioned in the decoke thread which really pushed me into decoking the whole engine)

http://forum.a8parts.co.uk/attachmen...1&d=1473973805

http://forum.a8parts.co.uk/attachmen...1&d=1473973805

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Few shots of the flaps

http://forum.a8parts.co.uk/attachmen...1&d=1473973805

http://forum.a8parts.co.uk/attachmen...1&d=1473973805

http://forum.a8parts.co.uk/attachmen...1&d=1473973805

http://forum.a8parts.co.uk/attachmen...1&d=1473973805

http://forum.a8parts.co.uk/attachmen...1&d=1473973805

http://forum.a8parts.co.uk/attachmen...1&d=1473973805

Flaps removed, actuator motors removed and manifold ready for cleaning.
One row of flaps was in very good condition while the other driven by the main set was absolutely worn out damaged in multiple places which makes no sense as you would expect the main set to be ruined which is driven the by actuator motor mounted at the front of the manifold.

Breaking off them ain't very easy, a strong flat head screwdriver with thin end is needed along with the hammer to break off three plastic rivets on each flap. You can see how some holes are worn out there where the flaps got loose before detaching from the base.

http://forum.a8parts.co.uk/attachmen...1&d=1473973805

http://forum.a8parts.co.uk/attachmen...1&d=1473973805

http://forum.a8parts.co.uk/attachmen...1&d=1473975785

http://forum.a8parts.co.uk/attachmen...1&d=1473975785

http://forum.a8parts.co.uk/attachmen...1&d=1473975785

http://forum.a8parts.co.uk/attachmen...1&d=1473975785

http://forum.a8parts.co.uk/attachmen...1&d=1473975785

http://forum.a8parts.co.uk/attachmen...1&d=1473975785

As mentioned earlier removing the silicon is a real pain and here are some shots of all the sealed are preped for sealing, all the inlets along with variable flaps cleaned/decoked and both parts of the manifold drying out in the sun after last and final rinse with the WD40 Degreaser.

http://forum.a8parts.co.uk/attachmen...1&d=1473975785

http://forum.a8parts.co.uk/attachmen...1&d=1473975785

http://forum.a8parts.co.uk/attachmen...1&d=1473975785

http://forum.a8parts.co.uk/attachmen...1&d=1473975785

http://forum.a8parts.co.uk/attachmen...1&d=1473975785

http://forum.a8parts.co.uk/attachmen...1&d=1473975785

For sealing the manifold I've used JB Weld Ultimate Grey Silicon
Very very hard to squeeze out so expect some rushing, sweating and your hands hurting at the end as hell.
I followed the instructions by hand tightening all the bolts first, leaving the silicon to set for half an hour and then doing all the bolts up by further quarter/half a turn using a torque wrench.
I got 4 tubes, used only 2, but there was more than half left in each left.
What could help is probably warming the tubes up in a bowl with very hot water.

http://forum.a8parts.co.uk/attachmen...1&d=1473975785

http://forum.a8parts.co.uk/attachmen...1&d=1473975785

And here is the middle part bolted on and bottom and top part finally sealed.

http://forum.a8parts.co.uk/attachmen...1&d=1473975785

http://forum.a8parts.co.uk/attachmen...1&d=1473975785

http://forum.a8parts.co.uk/attachmen...1&d=1473975785

http://forum.a8parts.co.uk/attachmen...1&d=1473975785

All actuators bolted back on (had one arm securing clips missing from the back on one of them so decided to pop in to Audi and order and replace all 3 of them).
All the excess of the silicon from outside trimmed.

http://forum.a8parts.co.uk/attachmen...1&d=1473975785

http://forum.a8parts.co.uk/attachmen...1&d=1473977011

http://forum.a8parts.co.uk/attachmen...1&d=1473975785

http://forum.a8parts.co.uk/attachmen...1&d=1473975785


DONE !!!
Very pleased with the job and result +++

http://forum.a8parts.co.uk/attachmen...1&d=1473975785

Very well done mate - I think you should be rightly proud of that one. Removing manifolds is not always a job for the fainted hearted but having a guide available will certainly make the job much, much easier for many and is a sound alternative given the cost of garage and replacement. Good work.

I think as you suggest, the minor loss of low end BHP or torque on a 5.2 V10 is going to be negligible, especially when offset against the cost and/or risk of a broken failing manifold.

Thank you very much +++
It was certainly a great thing to do for many reasons and satisfaction from doing it was and still is huge.
£250 repair seems a very good deal, but I only was 95% confident in it due to lack of pictures of the repair and this was the crucial 5% of me no, let's crack on with it and see what's is all about. On the end of the day if would have failed have way thru I could always sent a split manifold for the repair, but I knew from the beginning that the biggest challenge will be to split it, and it was.
I know that Ron is very pleased with his repaired manifold, but me being me and brutally honest, I've got slightly more doubts now in the repair process for such a small money considering what really is involved and how time consuming this process is. As a business I would probably charge at least £250 just for splitting the manifold and re-sealing it.
All in I'm very pleased and that loss of power if any isn't noticeable at all, when you floor it car responds the same way it was before with no weird lag or choking.

Fantastic job Marcin, and an excellent write up too +++

My lack of photos probably did you a favour, now you've "been there, done that" yourself, and probably have a much better understanding because of it. It's over two years now since my saga and I was very much at the mercy of those who had the car. One garage, Swift Motorsport, a local VAG independent specialist diagnosed the fault and stripped and cleaned the manifold (I witnessed it stripped down and cleaned when they showed me the failed flap) and the engineer carried out the repair for them after I was directed to him by someone who knew he'd done similar work previously. Even TPS helped me out by being incompetent as I was resigned to buying a new manifold and would have done had they been able to deliver, but that's another story.

I'm sure this will give others the satisfaction that preventative maintenance can be done to prevent failure, and even if failure comes it's not the end of the world. At the time of my drama all I could find were examples of them failing and causing engine damage and after seven weeks I was just glad to get the car back running as it should, as you can imagine.

This great forum, and the many knowledgeable people on it never fail to deliver, great work +++

Awesome write-up with lots of detail thanks for all the trouble you've gone to to write these up Marcin - added to sticky! +++

Superb post, well done for taking time to post up

My pleasure boys +++
It's something I've researched before, but a lot of detail was missing so I decided that's it, let's do it, document it and share with others as this is a common failure and no full guide out there.
Will post the graphs from the dyno run before the remap to see what the difference is vs. the one someone posted few months ago of a Silver S8.
It should be an interesting comparison.

Brilliant job.
I do this with my bikes. On them though its called flapper valve mod!.
Pull em out and it gives better induction and more roar under acceleration. It must sound awesome on our V10's. Once I move house next month I think this will definately be something I can get to grips with now with this perfect guide and the decoke.
Although Im still in 2 minds about paying the £800 AMD want to do it. Gotta be the easier option surely lol!!

Rick, satisfaction from doing it yourself and guarantee of both jobs being done properly as you can't check the results afterwards is priceless.
Then spend £400 out of £800 for a proper dyno run and remap, but before you do that spend £150 on injectors cleaning and you will still be left with £150 toward the beer fund as both jobs will cost you approx £100 in degreasers, wire brushes and sealant for the manifold +++

Once thats done mate its back to the dyno to see how many of the lost horses have come back to stable!
I was 128bhp down due to the control arms not being connected to the flaps! No air flow into the engine. They did recommend a decoke at the tjme as well.

Great write up, will be of use to many over the coming years I'm sure +++

Could someone please give me the details of the engineer that can repair the flaps?

I'd prefer them to remain installed and, just in case I find a problem when mine is done, it would be great to have the details of someone who could do the repair.

Same for me, I'd like to discuss with the engineer so I don't have to engineer myself.

If anyone has the details of the engineer that can repair the flaps, I'd really appreciate it.

My car will be going in soon and I'd like to be armed, in case a repair is required.

Anyone?

I followed this guide and removed my inlet manifold today.
I was advised by the previous owner of the car (who had also had a garage remove the manifold) that the flaps where damaged and the car is also throwing a fault code so I did it in good faith.


Turns out though that after splitting the manifold the flaps where all intact, however they have lots of play, especially in the input mechanism. Its definably not airtight anyway..

Here is a couple of pics (open and closed) and also a video. If you have experience in this please have a look and let me know if its worth removing them and mapping them out now that I have the manifold out or if I should just leave them in after degreasing everything.
Perhaps the fault was down to the amount of play in the system?

Attachment 16030
Attachment 16031

Video:
https://youtu.be/gDPneDxKV8Q

Also just to add to this great guide, Its possible to partly remove the manifold with out undoing the two t30 bolts that hold on the bracket for the injector wiring.
Once its then lifted out a little they come off much easier as there is heaps more access +++


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Hey Bo,

Taking them out is not really an option without damaging the 'bearings' as they are melted into position.
I have yet to find out how the sealing works on the input shaft (where the lever plate is attached) but I expect to find a very thick (maybe square) o-ring in a groove in the plastic so it will probably seal pretty well even though the play is quite excessive compared to a new one indeed.

I would advice when assembling it again to use a non setting sealant so in the future it will be easy to open again.

Now that the manifold is off it pays to renew the seal between the oil filter housing and the block.

Subscribe to this thread because in the future I will notify on here when my PCV delete kit is done so no more contaminating and deteriorating vapors into this relatively weak assembly, and when my repair kit is done for people with broken flaps.

Many thanks for the advice, so you would recommend to leave it as it is and just clean and decoke everything?
I also noticed on this thread that the pictures show each bearing for the relevant flap is riveted to the casing but when I ran my finger down the inside of the air way behind the bearings there are no plastic rivets sticking through its just smooth metal so perhaps these are melted on like you say.

Anyway thats not really important I just thought it was odd how they seam to be different.

I will do the inlet valves too as they are totally covered with build up of carbon.
Ill have a look at changing that seal on the oil filter housing too if thats worth doing.

Pcg valve delete
 

Please can you let me know as well, planning manifold flap delete and decode soon.

I finished my flap delete and decoke last week and have driven the car about 500 miles since then with out problems.

Its made a huge difference to the exhaust noise and I now no longer have suicidal rattle noises coming from the inlet manifold when the car is stationary and blipped to 2000+rpm.
Torque is a little down which is noticeable in 1st and 2nd but a remap should sort that.

None of the flaps where actually broken in my car but the whole assembly was extremely loose hence the rattle. I removed everything including the input linkage and filled the whole with an m14 bolt, nut and lots of sealant.

I also gave the upper manifold assembly a lick of high temperature paint :D

Attachment 16095

Good job mate and removing them was a good call too. Once they are loose that's it, fault will get worst much quicker.

I hear what you are saying about the injector connectors bracket, but it's impossible what you have done on the car which never had manifold out due to the wiring loom just before the connectors being fixed to the front of the engine block leaving you with no play on the manifold. Most likely guys who took it out didn't bother to reassemble it properly :tuttut:

Well done +++

Ha, the link wont work for me now I have all (i think) the bolts out. 12 torx and nothing else visable holding it down, just yank till it comes away??

Loose much torque?